Background: The aim of this study was to assess the effect of incorporation of zinc oxide nanoparticles (ZnO-NPs) to glass-ionomer cement (GIC) (Fuji II SC, GC Corp., Tokyo, Japan) on subgingival accumulation of mutans streptococci and lactobacilli under orthodontic bands. Materials and Methods: In order to conduct this in vivo split-mouth study, 20 patients aged between 7 and 10 years who required lingual holding arch on their mandibular first molars were divided into two groups. In one group, Fuji II SC GIC was used for cementation of the right molar band, and the same cement containing 2 wt% ZnO-NPs was used for the left one. The opposite was performed for the second group while the operator was blinded to the cement types. Subgingival microbial sampling was performed 16 weeks after cementation of lingual arch. Mutans streptococci and lactobacilli colony counts were compared. Paired t-test was used to compare the two cement groups. Data were analyzed using SPSS version 21, and P ≤ 0.05 was considered statistically significant. Results: The mean colony counts of mutans streptococci, lactobacilli, and total bacterial count in Fuji II SC containing ZnO-NPs were significantly lower than the corresponding values in plain Fuji II SC group. Conclusion: Incorporation of ZnO-NPs into GIC reveals antimicrobial features against mutans streptococci and lactobacilli under orthodontic bands.

Background: This study aimed to compare the success rate of inferior alveolar nerve (IAN) anesthesia in the mandibular first molars with symptomatic irreversible pulpitis using two anesthetic solutions of prilocaine and mepivacaine. Materials and Methods: The current randomized controlled clinical trial was conducted on 100 patients in two groups (n = 50). Standard injection of IAN block (IANB) was performed using two cartridges of 3% mepivacaine plain in the first group and using two cartridges of 3% prilocaine with 0.03 IU felypressin in the second group. Fifteen minutes after injection, the patients were asked about lip anesthesia. In case of a positive answer, the tooth was isolated with a rubber dam. Success was defined as no or mild pain on the basis of the visual analog scale recording upon access cavity preparation, entry into the pulp chamber, and initial instrumentation. Data were analyzed with SPSS 17 using the Chi-square test, and P < 0.05 was set as statistically significant. Results: The patients' pain severities during the three stages were significantly different (P = 0.001, 0.0001, and 0.001, respectively). The success rate of IANB during access cavity preparation was 88% with prilocaine and 68% with mepivacaine. This rate during entry into the pulp chamber was 78% and 24%, respectively, which was 3.25 times higher with prilocaine than mepivacaine. The success rates during instrumentation were 32% and 10%, respectively, which was 3.2 times higher with prilocaine than mepivacaine. Conclusion: The success rate of IANB in the teeth with symptomatic irreversible pulpitis was higher using 3% prilocaine with felypressin than using 3% mepivacaine.

Background: Rheumatoid arthritis (RA) is one of the most common chronic inflammatory diseases. Previous studies have reported an association between stress and salivary alpha-amylase. The aim of this study was to investigate the concentration of salivary alpha-amylase in patients with RA (by elimination of stress factor). Materials and Methods: In this case–control study, we enrolled 50 patients with RA and 48 healthy patients as the control group. The perceived stress scale questionnaire was used to evaluate scores of stress in both case and control groups, and then the participants with high scores of stress were excluded from the study. Moreover, the alpha-amylase activity kit was used for the assessment of the levels of salivary alpha-amylase. In all analyses, the significance level was considered to be < 0.05. Finally, the obtained data were analyzed by SPSS22. Results: Our results indicated a high score of stress in the case group (19.42 ± 5.83 units) compared with the control group (18.02 ± 6.07 units) which was not statistically significant (P < 0.248). Moreover, we demonstrated a high salivary alpha-amylase concentration in the case group (340.65 ± 38.04 units) compared to the control group (302.62 ± 58.72 units), which was statistically significant (P < 0.001). The sensitivity and specificity of this method, at >312 alpha-amylase concentrations, were 80% and 46%, respectively. Conclusion: In general, we indicated that the alpha-amylase concentration in patients with RA is higher than the healthy controls, and can be used as a codiagnostic factor.

Background: Cleft lip (CL) and cleft palate (CP) are among the most common birth defects in the craniofacial region affected by various environmental and genetic factors. The prevalence of these abnormalities varies in races and countries. Therefore, it is a necessity to design a website to register newborns with CL ± CP in Iran. This study aimed to design a website to record the characteristics of children with CL ± CP. Materials and Methods: First, a website was designed to register the characteristics of children with CL ± CP. To evaluate the accuracy of the website, the characteristics of all children (n = 31) with CL ± CP were recorded and analyzed. Results: Due to the capability of the website to print and create reports in Excel format, the data of registered patients were analyzed. Conclusion: As CL ± CP are very common defects around the world including Iran, it is necessary to design a website to record all information about these children in Iran. Hope this website helps the public health authorities to improve program effectiveness to treat these children.

Background: An ever-increasing demand is seen for clear aligners and transparent vacuum-formed retainers. They are esthetic and convenient. However, the biomaterials used in these appliances might pose biological safety and biocompatibility threats in terms of their bisphenol-A (BPA) release, cytotoxicity, adverse effects, and estrogenic effects. Due to the controversial results and the lack of any systematic reviews in this regard, we conducted this systematic review. Materials and Methods: Web of Science, PubMed, Cochrane, Scopus, and Google Scholar as well as references of the found articles were searched (independently by 3 researchers) up to December 22, 2021, to find studies relevant to the biocompatibility of clear aligners and thermoplastic retainers. The search keywords were a combination of the following (and more): Essix, vacuum-formed aligner, thermoplastic aligner, clear aligner, Invisalign, vacuum-formed retainer, BPA release, monomer release, cytotoxicity, estrogenicity, biocompatibility, chemical properties, and oral epithelial cell. As eligibility criteria, articles in all languages would be included as long as their text could be translated clearly using online translators or by professional translators; all types of publications (article, book, and thesis) would be included if containing relevant studies and information; they should have been on clear liners or thermoplastic retainers; and they should have been on biocompatibility, safety, cytotoxicity, or estrogenicity of clear aligners or thermoplastic retainers. There were no restrictions on the type of study (randomized clinical trials, experimental in vitro studies). Studies focusing merely on the mechanical properties of clear aligners or thermoplastic retainers (without examining their chemical properties) would be excluded. The risk of bias was assessed. Results: The risk of bias was rather low. However, the methodologies of the studies were quite different. Overall, 16 articles (1 randomized clinical trial and 15 in vitro studies) were identified. The data for BPA release were reported in four articles (1 clinical trial and 3 in vitro studies). Quantitatively speaking, the amount of released BPA reported by in vitro studies was very low, if not zero. However, the BPA level was very high in the only randomized clinical trial. Many adverse effects were linked to using clear aligners or transparent retainers, including pain and soft-tissue issues such as burning, tingling, sore tongue, lip swelling, blisters, ulceration, dry mouth, periodontal problems, and even systemic problems such as difficulty in breathing. Besides these biological adverse effects, oral dysfunctions and speech difficulties and tooth damage may be associated with clear aligners and should as well be taken into consideration. Conclusion: Given the very high levels of BPA leach observed in the only clinical trial and considering other possible dangers of small traces of BPA (even at low doses) and also given the numerous adverse events linked to clear aligners or transparent retainers, it seems that safety of these appliances might be questionable and more clinical studies of biocompatibility are needed in this regard.

Background: The digital dentistry, requires materials with wo opposite properties of machining ability and also enough hardness. The main objective of this experimental study was to investigate the fabrication feasibility of the lithium metasilicate glass-ceramic in partially crystalized stated using the spark plasma sintering (SPS) method. Materials and Methods: In this study, SPS for the first time was used to fabricate primary lithium metasilicate glass-ceramic (LMGC) blocks. The raw materials were mixed and melted and then quenched in water and the resulted frits were grinded. The resulting powder was sintered by SPS at 660, 680, and 700°C. Results: Scanning Electron Microscope (SEM), X-ray diffraction (XRD), and Vicker's microhardness assay were used to evaluate the properties of samples. Statistical comparison of the obtained data was performed by ANOVA, followed by the post hoc test of Duncan. Microstructural studies by SEM and XRD showed that all samples were composed of lithium metasilicate phase in a glassy matrix. With increasing the sintering temperature, the number and size of lithium metasilicate particles increased and higher mechanical properties have been achieved. However, the sintered sample at 700°C has less processing ability than the samples sintered at 660 and 680°C. Conclusion: The optimum sintering temperature for glass frit consolidation was determined by SPS at 680°C.

Background: Different studies about the effects of mouthwashes on force reduction by elastomeric chains are reported in the literature. Hence, this review was done for the assessment of force degradation in the elastomeric chains in different mouthwash compositions. This study helps to improve the clinical performance of elastomeric chains used in orthodontics, reducing force degradation, and finally assisting clinicians in choosing better and more efficient methods for their treatments. Materials and Methods: In this review article, an extensive search was performed in the electronic databases of Cochrane Library, Web of Science, PubMed, and Scopus from the year 1990–2020. No language restriction was considered and manually investigated the reference lists of all articles related to the title. Out of 450 obtained articles, 14 in vitro studies were chosen based on the inclusion criteria, and their quality was assessed using modified CONSORT. This systematic review was limited and written based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol. Results: Based on the results achieved, mouthwashes containing alcohol caused considerable force degradation in the elastomeric chains compared to the alcohol-free ones and mouthwashes with fluoride caused lesser force degradation compared to other types.

Background: Biodegradable hydrogel scaffold is one of the crucial characteristics that determine the success of pulp regeneration. The degradation should be suitable for the growth of new tissue establishment. The aim of this study is to synthesize and compare the novel biodegradable hydrogel scaffold based on hydroxyapatite (HAp) eggshell, collagen, and epigallocatechin-3-gallate (HAp-Col-EGCG) with different HAp concentrations in vitro. Materials and Methods: This study is original research. HAp-Col-EGCG hydrogel scaffolds were prepared using 1:1, 1:2, and 1:4 ratios of collagen and HAp with 10 μmol/L EGCG. The samples were freeze-dried and immersed in phosphate buffer saline containing lysozyme enzyme. The dried samples were weighed to determine the percentage of biodegradation value (P < 0.05). Results: The result showed HAp-Col-EGCG was biodegradable but it has not been concluded that it can be completely eliminated. The data were analyzed by one-way analysis of variance and it indicated significant differences in percentage values. Conclusion: Hydrogel scaffold based on HAp-Col-EGCG can be degraded and have the potential to be used as a biodegradable scaffold in supporting tissue regeneration.

Background: Polymethyl methacrylate resin is widely used in orthodontic treatments. Graphene oxide (GO) has reactive functional groups on its surface that facilitate binding to various materials such as polymers, biomolecules, DNA, and proteins. This study aimed to investigate the impact of adding functionalized GO nanosheets on the physical, mechanical, cytotoxicity, and anti-biofilm properties of acrylic resin. Materials and Methods: In this experimental study, fifty samples (for each test) were divided into groups of 10, in the form of acrylic resin discs with concentrations of 0, 0.25, 0.5, 1, and 2 weight percentage (wt%) of functionalized GO nanosheets and also the control group. Samples were evaluated in terms of physical properties (surface hardness, surface roughness, compressive strength, fracture toughness, and flexural strength), anti-biofilm properties (On four groups of micro-organisms, including Streptococcus mutans, Streptococcus sanguis, Staphylococcus aureus, and Candida albicans), and cytotoxicity. Data were analyzed using SPSS software version 22, descriptive statistics, one-way analysis of variance test, and Tukey post hoc test. The significance level was considered P < 0.05. Results: No significant difference was observed between the different groups with weight percentages of 0.25, 0.5, 1, and 2% nano GO (nGO) and the control group (without nGO) in terms of surface roughness and toughness. However, compressive strength, three-point flexural strength, and surface hardness showed significant differences between the groups. Furthermore, the degree of cytotoxicity increased by increasing the weight percentage of nano-GO. Conclusion: The addition of functionalized nGO in appropriate concentrations to polymethyl methacrylate can improve the anti-bacterial and anti-fungal biofilm properties without changing or increasing their physical and mechanical properties.

Background: The prevalence of oral squamous cell carcinoma (OSCC) has increased in recent years. With the development of various treatments, the mortality rate has decreased and more people are living with the consequences of the disease and its treatment, which can have a great impact on the quality of life. Some questionnaires measure the impact of the disease on daily activities and patient behavior. In this study, the oral health-related quality of life (OHRQOL) was assessed through the Oral Health Impact Profile (OHIP)-14 questionnaire between the OSCC patient and control groups. Materials and Methods: In this cross-sectional study, the OHIP-14 questionnaire was given to 51 OSCC patients who had completed the treatment at least 6 months before participating in this study and 51 healthy individuals, and we used the Chi-square test, independent sample t-test, one-way ANOVA, and linear regression in three models. P = 0.05 was considered statistically significant. Results: The mean age of patients was 55.86 ± 15.04 years and the control group was 54.96 ± 14.08 years. Women made up 51% of patients. The mean OHIP score was 22.84 ± 11.42 in the patient group and 17.92 ± 9.23 in the control group, which indicates a significant (P = 0.005) difference between the two groups according to the independent sample t-test. Conclusion: The OHRQOL of patients has significantly decreased compared to the control group. Surgery had the lowest quality reduction, and combined surgical treatment with radiotherapy and chemotherapy had the highest reduction in the OHRQOL. It is recommended to have regular follow-up sessions and to have a proper diet during and after treatment.

Background: Surface smoothness considered to be a significant part of the appearance and success of the restorative materials. The aim of this study was to assess the influence of four different polishing systems on surface roughness of four resin composite materials when subjected to thermocycling. Materials and Methods: This research was designed as a comparative study. Four resin composites were used which are: Nanofill composite (Filtek Supreme XT), nanohybrid composite (Tetric EvoCeram), microfill composite (Renamel Microfill), and microhybrid composite (Filtek Z250). Sixty disk-shaped specimens of each resin composite were prepared then divided into four groups according to the polishing system (n = 15); which were Sof-Lex Spiral, Diatech Shapeguard, Venus Supra, and Astropol. The specimens of each group were polished following the manufactures' instructions, then surface roughness, R_a values in μm were measured initially and after the specimens subjected to thermal cycling. The influence of resin composites, polishing systems, thermocycling, and their interaction effects on surface roughness (R_a mean values) was statistically analyzed mainly by using the repeated measures two-way analysis of variance test, whereas the Bonferroni''s post hoc test was applied for pair-wise comparisons. P ≤ 0.05 was used as the significant level. Results: The results of this study revealed that Filtek Supreme XT recorded significantly the lowest mean surface roughness (R_a) of 0.2533 ± 0.073 μm (P < 0.001). The Sof-Lex Spiral polishing system revealed significantly the lowest mean surface roughness (Ra) of 0.2734 ± 0.0903 μm (P = 0.004). Regardless of composite type and polishing system, there was a statistically significant increase in mean surface roughness values (R_a) in μm after thermocycling (0.2251 ± 0.0496 μm and 0.3506 ± 0.0868 μm, respectively) (P < 0.001). Conclusion: Resin composite type, polishing method, and thermocycling aging significantly affected the surface roughness of composites; Nanofill composite and Sof-Lex Spiral polishing system provided the lowest values of surface roughness which increased after thermocycling.

Transplantation of one tooth to another site in the same individual can be considered an attractive alternative to dental implants or fixed prostheses. This study reports the treatment results of a 16-year-old female with severe crowding in upper and lower arches and a fractured mandibular premolar with a poor prognosis. The crowding of the lower left quadrant was relieved by the extraction of the first premolar. This extracted tooth with a complete root was transplanted to the right quadrant with the fractured tooth. Platelet-rich fibrin can stimulate and accelerate periodontal healing. The platelet concentrate of this patient was prepared and applied to the socket wall at the time of surgery. The acceptable occlusion and the excellent 4-year prognosis of the transplanted tooth are presented.

Background: Occlusal loading of osseointegrated implants is believed to be an essential determining factor in the long-term success of an implant treatment. Numerous studies have been conducted on the evaluation of stress distribution by definitive restoration materials for Implant-supported fixed prosthesis, but very few have evaluated provisional restoration materials for the same. This study aims to evaluate the influence of provisional restoration material – Milled Polymethylmethacrylate (PMMA) and Milled Polyetheretherketone (PEEK), over stress distribution on the peri-implant bone around an implant-supported three-unit, fixed dental prosthesis using finite element analysis method. Materials and Methods: Three-dimensional models of a pair of bone-level implant system and titanium base abutments were created using the standard tessellation language data of original implant components. A bone block representing the mandibular posterior area was created, and the implants were placed in the bone block with 100% osseointegration in the 2nd premolar to 2nd molar region. A superstructure of an implant-supported 3-unit bridge was modeled on top of the abutments, each crown to be 8 mm in height and with an outer diameter of 6 mm in 2^nd premolar region and 10 mm in 1^st molar and 2^nd molar region. Two different models were created according to combinations of provisional restoration materials, namely, Milled PMMA and Milled PEEK based on. In each model, the implants were loaded vertically (300 N) and obliquely (150 N at 30°). The stress distribution in the cortical bone, cancellous bone, and implant was evaluated through the von Mises stress analysis. Results: The results showed no difference in stress distribution due to the different provisional restorations – Milled PMMA and Milled PEEK. In addition, the vertical load resulted in higher stress values in the implant components, cortical bone, and cancellous bone in both PEEK and PMMA models as compared to oblique loading. Conclusion: The new polymer, PEEK was seen to provide comparable stress generation in the current study without exceeding the physiological limits of peri-implant bone. Thus, it can be considered as a good alternative to PMMA resin as a provisional crown material since it provides certain additional benefits.

Background: The burden of oral diseases is increasing, which constitute a major public health problem. The use of probiotics as an adjuvant, along with routine dental care practice by an individual, can produce additional benefits in the maintenance of one's oral health. The study aimed to investigate the effect of Bifidobacterium as a probiotic on oral health. Material and Methods: Six databases and registers were searched from the start of the database to December 2021 without any restrictions. Randomized controlled trials (RCTs) evaluating the clinical effects of Bifidobacterium as a probiotic on oral health were included in the study. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed to conduct this systematic review. The included studies were analyzed for the risk of bias using the Cochrane risk-of-bias tool for randomized trial (RoB 2) tool as well as quality of available evidence using GRADE criteria. Results: From the 22 qualified studies, four studies showed non-significant results. There was a high risk of bias in 13 studies and some concerns of bias in nine studies. No adverse effects were reported, and the quality of available evidence was moderate. Conclusion: The effect of Bifidobacterium on oral health is questionable. Further high-quality RCTs are required on the clinical effects of bifidobacteria and also the optimum level of probiotic needed, and ideal mode of administration to provide oral health benefits. Furthermore, synergistic effects of the combined use of various strains of probiotics need to be studied.

Root perforation may occur at any stage of endodontic treatment and is mostly due to iatrogenic injury and may compromise the outcome of endodontic treatment. Repairing a perforation is difficult and the prognosis depends on various factors such as time, site and size of perforation, and the patient's overall health status. Hence, choosing the most appropriate material can be critical for the dentist. In this case report of a strip-perforation repair, an mineral trioxide aggregate-like material (cold ceramic) that has been shown in previous studies to have favorable properties, was successfully used.

Background: Dentistry practice has become more complex and challenging in the recent years. The clinical decision-making process has experienced many problems due to changing socioeconomic patterns, knowledgeable patients, rapid technological advances, and information explosion. The present study reviewed the status of the attitude toward evidence-based dentistry (EBD) among dental students of Iran Universities. The effect of the educational intervention was also assessed. Materials and Methods: This systematic review was conducted according to the Preferred Reporting Items for Systematic review and Meta-Analysis checklist. Search strategy was developed by Medical Subject Headings terms and keywords surfing electronic available databases including Medline/PubMed and Google Scholar and local databases such as Scientific Information Database (SID) and Magiran. Two reviewers read the abstracts of all eligible papers and excluded the duplicates. They extracted the information of the full-text of the studies included in the review and assessed the quality by Joanna Briggs Institute critical appraisal checklist. Results: Ten studies including 8 cross-sectional and 2 interventional studies met the criteria. The assessment of the attitude of 937 dental students from a different region of the country toward EBD showed moderate to acceptable status using 3 different tools. In regard to educational interventions, 2 studies were successful to improve their attitude. Conclusion: Although the researchers presented good scores on the attitude questionnaires, the quality of the study tools, the eligible criteria for recruiting the participants and the method of evaluating the construct of attitude should be investigated in future studies.

Background: This in vitro study aimed to compare the fracture resistance of fiber post and reversed-oriented metal post in the restoration of severely decayed primary incisors. Materials and Methods: In this in vitro study, forty extracted human primary incisors were sectioned horizontally 1 mm above the CEJ and randomly divided into four groups – Group 1: Central incisors restored with reverse-oriented metal post, Group 2: Lateral incisors restored with reverse-oriented metal post, Group 3: Central incisors restored with fiber post, and Group 4: Lateral incisors restored with fiber post. The coronary portion of the teeth was then restored with nanohybrid universal composite. The fracture resistance was measured using universal testing machine. The type of fracture was determined by employing a stereomicroscope. Data were analyzed using two-way ANOVA test. The level of significance was considered at P < 0.05. Results: The mean fracture resistance of glass fiber posts (208.00 ± 73.19) was higher than the reverse-oriented metal posts (190.37 ± 56.36); however, there was no significant difference between any of the groups (P = 0.353). Conclusion: Within the limitations of this study, it can be concluded that both types of posts studied in the present research can be successfully used in the restoration of severely damaged primary incisors.

Background: The aim of this study was to investigate the effect of bleaching agent, sodium ascorbate as an antioxidant, and delay time on the shear bond strength (SBS) of orthodontic brackets to enamel using Transbond XT and universal adhesive. Materials and Methods: In this in vitro experimental study, 80 extracted maxillary premolars without any defect or decay were randomly divided into eight groups of 1: no bleaching + Transbond XT (NB/TX) bonding agent, 2: no bleaching + All-Bond Universal (NB/AB), 3: bleaching + Transbond XT (B/TX), 4: bleaching + All-Bond Universal (B/AB), 5: bleaching + sodium ascorbate + Transbond XT (B/SA/TX), 6: bleaching + sodium ascorbate + All-Bond Universal (B/SA/AB), 7: bleaching + Transbond XT after a 3-week delay (B/3W/TX), and 8: bleaching + All-Bond Universal after a 3-week delay (B/3W/AB). After thermocycling (1000 cycles, 5–55°C), the SBS was measured, and the adhesive remnant index scores were determined to assess the failure mode. Data were analyzed by one-way analysis of variance, Tamhane's post hoc test, Kruskal–Wallis, and Mann–Whitney U-test at the significance level of P < 0.05. Results: The mean SBS range was 5.5–29.78 MPa. The highest SBS values were related to Group 2 (NB/AB) which were significantly higher than all groups (P < 0.05) and the lowest values were observed in Group 5 (B/SA/TX) which were significantly lower than all groups except Group 3 (B/TX) (P < 0.05). Conclusion: Bleaching with 40% hydrogen peroxide significantly decreased the SBS of orthodontic brackets, and 10% sodium ascorbate could not reverse the adverse effect of bleaching on SBS. Delaying the bonding procedure by 3 weeks using Universal adhesive considerably decreased the adverse effect of bleaching on SBS and increased the SBS to a clinically acceptable level for orthodontic treatment.

Background: Panoramic radiography is a standard diagnostic imaging method for dentists. However, it is challenging to detect mandibular trauma and fractures in panoramic radiographs due to the superimposed facial skeleton structures. The objective of this study was to develop a deep learning algorithm that is capable of detecting mandibular fractures and trauma automatically and compare its performance with general dentists. Materials and Methods: This is a retrospective diagnostic test accuracy study. This study used a two-stage deep learning framework. To train the model, 190 panoramic images were collected from four different sources. The mandible was first segmented using a U-net model. Then, to detect fractures, a model named Faster region-based convolutional neural network was applied. In the end, a comparison was made between the accuracy, specificity, and sensitivity of artificial intelligence and general dentists in trauma diagnosis. Results: The mAP50 and mAP75 for object detection were 98.66% and 57.90%, respectively. The classification accuracy of the model was 91.67%. The sensitivity and specificity of the model were 100% and 83.33%, respectively. On the other hand, human-level diagnostic accuracy, sensitivity, and specificity were 87.22 ± 8.91, 82.22 ± 16.39, and 92.22 ± 6.33, respectively. Conclusion: Our framework can provide a level of performance better than general dentists when it comes to diagnosing trauma or fractures.

Background: The aim of this study was to compare the clinical, histological, and histomorphometrical outcomes of CenoBone^® allograft with and without plasma rich in growth factor (PRGF) for the preservation of edentulous ridge in the dental sockets. Materials and Methods: This study is experimental clinical trial that 14 dental sockets were included the sockets required ridge preservation followed by implant placement in the premolar and molar of the mandible. After extraction of the teeth, the CenoBone^® allograft and PRGF were used in the test group and CenoBone^® allograft was used alone in the control group. During the first stage of surgery and 5 months later, in the second stage of surgery (implant placement), the vertical changes of the ridge were measured. Furthermore, using Core-Biopsy in the second stage of surgery, criteria of histologic and histomorphometric were determined. Data were analyzed with t-test, Mann–Whitney U-test, and Fisher's exact test at the level of significance of P < 0.05. Results: The mean trabecular thickness in the test group (52.18 ± 5.53) was significantly higher than that in the control group (41.53 ± 10.40) (P = 0.344). However, there were no significant differences in the mean values of vertical bone absorption, bone percentage, remaining biomaterials, inflammation, and blood vessels between the two groups. There was no case of foreign body reaction and the bone was vital in all the cases and in direct contact with the biomaterial. Conclusion: Although CenoBone^® allograft with PRGF was effective in some histomorphometric factors such as trabecular thickness, it did not lead to significant clinical changes.

Background: During the orthodontic bonding process, the need for repositioning or rebonding of orthodontic brackets on the enamel surface occurs frequently. The aim of this study is to compare the shear bond strength (SBS) in rebonding orthodontic stainless steel brackets with three different methods of enamel surface conditioning methods. Materials and Methods: In this in vitro study, 80 human premolars that were extracted for orthodontic purposes were randomly divided into four groups and underwent orthodontic bonding procedure (N = 20). Except for the control group, three other groups underwent debonding and rebonding process in which after removing the remaining adhesive with tungsten-carbide bur, enamel surface conditioned by three different methods including re-etching with phosphoric acid, sandblasting + acid etching, and Erbium-doped Yttrium–Aluminum–Garnet laser. Then, the SBS of the bracket to the enamel surface was compared between different groups. Scanning Electron microscopy images were also obtained from a number of samples. Statistical analysis was performed by Kruskal–Wallis and Mann–Whitney tests. Results: The highest SBS was observed in the primary bond (control group) with an average of 29,440 MPa. There was a significant difference between the studied groups (P < 0.001) and only the group that was re-etched with phosphoric acid had no significant difference with the control group (P = 0.708) ∝ =0.05. Conclusion: Rebonding of brackets using phosphoric acid for reconditioning of the enamel surface creates bond strength comparable to the primary bond. Other groups had significantly lower SBS than the control group.

Background: This study aimed to assess the effect of laser irradiation and Tooth Mousse on tooth hypersensitivity (TH) after office bleaching (OB). Materials and Methods: This clinical trial, parallel-design split-mouth nonrandomized was conducted on 30 patients requiring OB. After scaling and fabrication of a custom tray, 35% hydrogen peroxide was applied on all teeth, and 940 nm diode laser (10 W, Class IV, 110–240 V) was irradiated to the upper and lower right quadrants. Laser in off mode was used for the left quadrants. Bleaching agent was then reapplied. After completion of bleaching, a custom tray containing tooth Mousse was placed on the maxillary arch while the tray was used without the paste for the mandibular arch. A visual analog scale was used to assess the degree of TH at 15 min and 24 h after OB. Data were compared using t-test, paired t-test, and analysis of variance. Significance level was set at α = 0.05. Results: Comparison of TH at 15 min and 24 h after OB showed a significantly lower TH score in the left upper quadrant (tooth Mousse alone) than right upper quadrant (both laser and Tooth Mousse) (P < 0.05). The TH score in the right upper quadrant was significantly lower than that in the right lower quadrant (laser only) (P < 0.05). The mean TH score in the left upper quadrant was insignificantly lower than that in the left lower quadrant (no intervention) (P > 0.05). Conclusion: The use of 940 nm diode laser for OB increases the postoperative TH. The application of Tooth Mousse can effectively decrease TH after OB with/without laser irradiation.

Background: Bonded composites may increase bacterial accumulation and caries formation risk. Therefore, assessment of methods to decrease bacterial activity around them would be valuable. The literature on the efficacy of adding silver nanoparticles to fiber-reinforced composite (FRC) or adding them to bonding agents in terms of their antibacterial activity and/or shear bond strength (SBS) is scarce. Thus, we aimed to assess the antibacterial activity of flowable composites and bonding agents containing various percentages of experimental silver nanoparticles (nanosilver) against S. mutans and to evaluate the SBS of FRC and bonding agents containing different amounts of nanosilver to enamel. Materials and Methods: In this preliminary study, 0% (control), 0.5%, 1%, 2.5%, and 5% nanosilver were added to flowable composite and bonding agent. Syntheses of nanosilver and nanosilver-incorporated composite specimens were approved using X-ray diffraction spectroscopy and scanning electron microscopy. Antibacterial effects of the produced materials on S. mutans were evaluated by colony count with serial dilution method (n = 7 groups × 10 [n = 70] specimens) and agar disc diffusion test (n = 6 groups × 5 [n = 30] composite specimens + n = 6 groups × 5 [n = 30] light-cured bonding + n = 6 groups × 5 [n = 30] uncured bonding) against negative control and cefotaxime antibiotic. Moreover, SBS values of various FRC blocks bonded to enamel using various bonding agents were measured (n = 9 groups × 6 [n = 54] human premolars). Data were analyzed using Kruskal–Wallis, Dunn, two-way analysis of variance, and Tukey's tests (α = 0.05). Results: Composite discs containing all concentrations of nanosilver reduced S. mutans colony counts (P < 0.05); bacterial growth was ceased at samples containing 2.5% and 5% of nanosilver. The reduction in the SBS of FRCs was significant only for 5% nanosilver (P < 0.05). Conclusion: Adding 0.5%, 1%, and 2.5% nanosilver to composite and 0.5% or 1% nanosilver to bonding agent led to a significant antibacterial behavior against S. mutans while not significantly affecting the SBS of FRC.

Background: The temporary cement remaining inside the dental prosthesis can act as a source of microbial colonization and contamination and decrease the final cement retention. Consequently, complete removal of temporary cement before permanent cementation is suggested. This study aimed to assess the effect of different cleaning methods for removing temporary cement on the tensile bond force (TBF) of permanently cemented implant-supported zirconia copings. Materials and Methods: In this in vitro study fifty titanium abutments were screwed onto 50 analogs with 30 Ncm torque into in acrylic resin blocks. Each abutment was scanned separately, and 50 zirconia copings were designed and milled. Permanent resin cement was used to cement copings of control group (N = 10). Copings were divided into two temporary cementation types that in each group, two cleansing methods were used: Temp-S (temporary cement with eugenol and sandblasted after debonding), Samples of the control group were placed in the universal testing machine, and the TBF values were recorded. Samples of the test groups after debonding and cleaning the abutments were subjected to cement with permanent resin cement, aging, and removing. Levene test, two-way analysis of variance (ANOVA), and Tamhane post hoc tests were applied. α = 0.05. Results: The highest and lowest TBF values were found for the TempNE-SU (554.7 ± 31.5 N) and Temp-S (492.2 ± 48 N) groups, respectively. The two groups of isopropyl alcohol baths in ultrasonics in combination with sandblasting showed statistically higher TBF values than the other two groups that used only sandblasting (P < 0.001) and had similar values compared to the control group. Conclusion: Sandblasting combined with immersion in an ultrasonic bath containing isopropyl alcohol resulted in statistically similar values to the values of cementation with resin cement from the beginning. However, cleaning the inside of the copings only by sandblasting method reduced the values of the final retention force in comparison to cement with permanent resin cement from the beginning.

Background: The use of a rubber dam is more important than ever in today's COVID-19 era to limit cross infections. In children, the placement of the metal clamp to retain the rubber dam is perceived to be painful and often requiring a local anesthetic injection. This dissuades many clinicians from placing the rubber dam. Hence, this study evaluated the pain response of children to a SoftClamp^™ compared to the conventional metal clamp. Materials and Methods: This was a randomized controlled, equal allocation ratio, split-mouth clinical trial. Forty-two children aged between 8 and 12 years, having two permanent mandibular molars in need of sealants, were divided into Groups A and B (metal clamp and SoftClamp^™, respectively). The pain response was recorded using both an objective and a subjective scale i.e., the Faces Legs Activity Cry Consolability (FLACC) scale and the Wong Baker Faces Pain Rating Scale (WBFPRS). The level of significance was set at 5% (P < 0.05). The pain response recorded from the WBFPRS and the FLACC scale for the metal and the SoftClamp^™ were analyzed using the Wilcoxon signed rank test. The difference in pain response between genders and between two age groups (below and above 10 years of age) was analyzed using the Mann–Whitney U-test. Results: The children reported mild discomfort to clamp placement in both the scales. The P values for the FLACC and WBFPRS scores comparing the pain response to the metal and SoftClamp^™ were 0.311 and 0.149, respectively. Conclusion: There was no significant difference in the pain response of children to both the clamps. Good rubber dam application practices in children through the use of behavior guidance and a proper topical anesthesia technique may play a far more important role regardless of the clamp used. But the SoftClamp^™, with its more child friendly appearance could be a viable alternative to the metal clamp in children.

Background: The demand for an ideal root canal filling material in primary teeth with maximum antibacterial properties keeps escalating to improve the success rate of root canal treatment in primary teeth. Hence, the present study was conducted to determine the antimicrobial efficacy of the different concentrations of a novel root canal filling material. Materials and Methods: An in vitro study was designed to compare the antimicrobial efficacy of different concentrations of the novel obturating material for primary teeth. Different concentrations of the novel obturating material were prepared using calcium hydroxide, zinc oxide cement, and metronidazole and were tested for its antimicrobial efficacy against Streptococcus mutans and Enterococcus faecalis using Mueller–Hinton Agar for 24 h at 37°C. The zone of inhibition was measured in millimeters after 24 h. The values were entered into a Microsoft Excel spreadsheet and subjected to statistical analysis. Descriptive statistics were used for data summarization and presentation. Friedman test and Kruskal–Wallis test were used to compare the different concentrations of the novel obturating materials against S. mutans and E. faecalis. P < 0.05 was considered to be significant. Results: Against S. mutans at 1% concentration, the zone of inhibition was statistically greater at 50 μl and at 2% and 3%, the zone of inhibition was greater at 100 μl. Similarly, against E. faecalis, the zone of inhibition was statistically greater at 100 μl at 2% and no significant difference was noted at 1% and 3%. Comparison between the groups at 25, 50, and 100 μl shows no significant difference against S. mutans between 1%, 2%, and 3% of 60–40 concentration. However, 3% 60–40 concentration at 50 μl shows significantly increased zone of inhibition against E. faecalis. Conclusion: Two percentage metronidazole at 60–40 (calcium hydroxide–zinc oxide) concentration of the novel obturating material at 100 μl has better antibacterial properties against both S. mutans and E. faecalis.

Background: The present study was conducted to develop a standard questionnaire to assess the knowledge and practice of prosthodontists regarding the diagnosis and treatment of obstructive sleep apnea syndrome (OSA). Materials and Methods: This study had questionnaire designing and cross-sectional-descriptive phases. Questionnaire domains were identified by a panel of eight experts. The face and content validity of the questionnaire was assessed by experts and four laypeople. The internal consistency reliability of the questionnaire was checked using Cronbach's alpha coefficient. Moreover, its stability was tested using the test–retest method. The questionnaire was completed online by 282 Iranian prosthodontists and the relationship between different variables and scores of knowledge and practice of them with simple and multiple linear regression tests was were analyzed. Results: A 32-item questionnaire was designed. The Scale Content Validity Index was >0.8 for clarity, simplicity, and necessity in all domains and the content validity of all questions was above 0.8. As for reliability, Cronbach's alpha coefficient was above 0.7 on average. Faculty members had more knowledge (P = 0.04) and better practice (P = 0.001) compared to others. Prosthodontists who participated in sleep disorders training courses had higher scores in knowledge (P = 0.001) and practice (P = 0.001). Prosthodontists who referred patients to sleep disorders clinics had higher knowledge (P = 0.001) and practice (P = 0.001) than those who did not. Conclusion: The questionnaire developed in this study can be considered a comprehensive and executable scale with appropriate reliability and validity. There is a positive relationship between being exposed to information and the level of knowledge and practice of prosthodontists about OSA.

Background: Minimally invasive techniques should be employed to maintain pulp vitality without affecting physiological tooth resorption for pediatric patients. This study aims to evaluate clinical and radiographic success of light cure calcium silicate and resin-modified glass ionomer (RMGI) as indirect pulp-capping agent in primary molars in children between 5 and 9 years. Materials and Methods: In this randomized clinical trial study, 40 primary molars with the International Caries Detection and Assessment System criteria 4–6 score were divided randomly into two groups after computerized randomization method. After caries excavation by minimally invasive dentistry principle, affected dentin was lined by either light cure calcium silicate (Group I) or RMGI (Group II) liner followed by composite restoration. Clinical success was determined with the absence of symptoms and bitewing radiographs were taken at baseline, 3, and 6 months' interval to measure increase in dentin increment using ImageJ software. Statistical analysis for intergroup comparison was done using Paired t-test, and Independent t-test was used for intragroup comparison. The level of statistical significance was set at P < 0.05. Results: Change in dentin increment seen from baseline to 6 months in Group I was 0.19 mm and in Group II was 0.20 mm (P = 0.924). Intragroup increment was statistically significant during all follow-up intervals for both the groups (Group I – P ≤ 0.001, Group II – P = 0.009). For baseline remaining dentin thickness >1.5 mm, statistically significant increase was observed in the dentin increment at 3 months' interval between both the groups. Conclusion: Both TheraCal LC and Vitrebond show acceptable clinical and radiographic results when used in primary molars as indirect pulp treatment agents. Both the liners are equivalent to each other in terms of feasibility and cost-effectiveness but TheraCal LC can be preferred due to better handling and avoiding the manipulation step thereby reducing treatment time.

Background: Pain following surgical removal of impacted molars has remained a principal concern among practitioners. Since green tea has anti-inflammatory and anti-bacterial properties, the current study aimed to evaluate the efficacy of green tea extract local application in controlling postoperative pain following surgical extraction of the impacted mandibular third molar teeth. Materials and Methods: In a double-blinded randomized controlled trial study with a split-mouth design, 32 patients underwent bilateral removal of impacted third molars in a 2-month time interval; afterward, the sterile gauzes impregnated with green tea extract and saline were applied randomly to the surgical sites. Postoperative pain was evaluated 6, 12, 24, and 48 h after surgery using a questionnaire based on the Visual Analog Scale (VAS) and the number of analgesics used after surgery. Data were subjected to exact and Chi-square tests with the significance level set at 0.05. Results: There was a decrease in the mean scores of the VAS and the mean number of analgesic consumptions in the first 2 days after surgery. Chi-square test results showed a significant reduction in the VAS scores after applying the green tea extract only 6 and 12 h after surgery (P < 0.05). Moreover, the number of analgesic consumptions was significantly lower in the green tea group compared to the control group. Conclusion: Green tea extract may be an appropriate and safe choice for postoperative pain control after surgical extraction of the impacted mandibular third molar teeth.

Background: Xenogeneic grafts have gained attention due to advantages in compare of autografts. This study aimed to compare Xeno (ostrich) Acellular Dermal Matrix (XADM) with the free gingival graft (FGG) to increase the width of Keratinized gingiva (KGW) in dogs. Materials and Methods: This split mouth animal study was performed on 10 mixed breed dogs. The upper second premolar sites were randomly selected for grafting by XADM (test) or FGG (control). Measurements of KGW were recorded before surgery, 1, 3, and 6 months after surgery. Biopsies from grafted sites for histologic and histomorphometric evaluations were harvested 6 months after surgery. Data were analyzed by repeated measured, paired samples t-test, and Wilcoxon Signed rank test. P < 0.05 was considered statistically significant. Results: KGW increased in the two study groups after surgery with no significant statistical difference between them at any time intervals (P > 0.05). The graft shrinkage was 23% and 21% for the test and control groups, respectively, without statistically significant difference (P > 0.05). Histomorphometric evaluation showed no significant difference between the two study groups. Foreign body reaction was not seen in any of the study groups. Conclusion: Increased KWG was similar between the two study groups. With regard to FGG limitations, XADM may be assumed as a suitable alternative for FGG. It should be noted that this research was an animal study and clinical trials on human should be performed to approve the efficacy and safety of this material.

Background: Pulpotomy is the most common pulp treatment of primary molars, where surgical amputation of infected coronal pulp results in preserving the vitality and function of radicular pulp. With introduction of newer materials, the emphasis has shifted towards regeneration, in this scenario; novel materials such as platelet derived growth factor (PDGF) and propolis (PS) have been considered. Materials and Methods: This was a single-blind in vivo study; ninety human primary teeth from children aged between 5 and 10 years were divided into three equal groups in whom pulpotomy procedure was performed and they were recalled after 3- and 6-month interval for histological evaluation. Observations were subjected to statistical analysis using Pearson's Chi-square test. Results: No statistically significant difference was found between the three materials with respect to inflammatory response, soft-tissue organization, and dentin bridge formation (P > 0.05). Majority of the samples in both growth factor and propolis exhibited dentin bridges at the interface of the exposed pulp, bringing or attempting to bridge the site exposed to the pulpotomy material. The ability of the material to evoke a foreign and inflammatory cell response in the pulpal tissue was not significant. The samples of both formocresol and growth factor group showed signs of pulpal necrosis which revealed the presence of a mild necrotic zone in one specimen at 3 months. One specimen from the propolis group showed mild areas of necrosis at the end of 6 months, where none of the specimens in the growth factor group showed areas of necrosis at the end of 6 months. Conclusion: The results of the present study showed a positive outcome for growth factor and propolis groups. Further clinical trials with a larger sample size and long-term review have to be conducted for the material to be used widely.

Background: There are controversies on the analgesic and anti-inflammatory effects of low-level laser therapy on pain, edema, and trismus after mandibular third molar extraction surgery. This study aimed to evaluate the efficacy of low-level laser therapy (LLLT) on discomforts occurring after the mandibular wisdom tooth removal. Materials and Methods: This double-blind, split-mouth design, randomized clinical trial study was performed on 36 healthy controls with bilateral symmetrical mandibular third molar referred to the Department of Oral and Maxillofacial Surgery of Dental Faculty from January to November 2019. After surgical extraction, the laser group underwent laser (Ga-Al-As diode laser, 808 nm, 200 mW) intraorally and extraorally just after surgery and 24 h after surgery. For the placebo group, the handpiece was inserted without laser irradiation. The pain level was assessed by Baker Wong scale at 2, 4, 6, 12, 24, 36, 48, and 60 h postoperatively, and the edema and the extent of mouth opening were examined before surgery, at the 1^st and 7^th days after surgery. The data were collected and analyzed by SPSS at the significant level of 0.05. Results: The statistical analysis of 32 participants' data (laser group: n = 32, placebo group: n = 32) indicated that the mean score of pain in 3 days after surgery in the interventional group was significantly lower than the score of the placebo group (P < 0.001). Furthermore, the swelling and the extent of the mouth opening differed significantly between the two groups at 1^st and 7^th days after the procedure (P < 0.001). Conclusion: Our findings showed that the LLLT had beneficial effects on the management of pain, edema, and trismus following after 3^rd molar extraction surgery.

Background: The fetal amniotic membrane is a biological graft with unique qualities which all lead to wound protection, reducing discomfort, and achieving adequate epithelialization. Materials and Methods: In this animal study, the second and third premolars of the mandible of 4 dogs were extracted. After 4 weeks, 20 mm of mandibular premolar site area were resected on both sides. The created defects on both sides were filled with xenograft. On one side, an amniotic membrane was placed over the graft particles and the reflected flap was sutured. The amount of bone formation in the defects was measured after 4 weeks for two of the dogs and after 8 weeks for the other two, using a caliper. Three histopathological samples from both sides were taken. The collected data were subjected to statistical analysis (Wilcoxon signed-rank and paired sample t-test) using SPSS software at a significant P = 0.05. Results: In the test group, the quantity of bone was 56.81, whereas in the control group bone quantity was 37.38 with statistically significant differences (P = 0.025). In the amniotic membrane group, the inflammation intensity after the graft procedure was moderate (50%) in comparison to the control group where the inflammation was severe (62.5%) (P = 0.041). Conclusion: The amniotic membrane can induce positive osteoinduction effects and be helpful in repairmen of bone defects such as the natural periosteum.

Background: Odontogenic keratocyst (OKC) is one of the most common jaw cysts with high recurrence rate. Some possible factors affecting recurrence that have not been evaluated in previous studies are examined in this study. This study aimed to predict the recurrence rate of OKC and more viable treatment of OKC. Materials and Methods: In this descriptive, analytical, and cross-sectional study, 10 recurrent OKCs, which both slides before and after recurrence were accessible, were collected from oral and maxillofacial pathology department's archive. First, they were evaluated based on common histopathologic features. In the second phase, the frequency of these findings in 36 OKCs (24 samples with recurrence and 12 without recurrence after 5 years) was evaluated based on clinical, radiological, and histopathologic features. Data were analyzed by SPSS, Wilcoxon signed-rank test, McNamara, t-test, Chi-square, Mann–Whitney, Fisher's exact test, Cohen's kappa coefficient, and odds ratio (P < 0/05). Results: According to this study, OKC in women, with multilocular radiolucency and mitosis in basal layer of epithelium as well as diffused inflammation, were statistically associated with probability of recurrence (P = 0.05, 0.035, 0.033, and 0.045, respectively). The corrugated surface, reverse polarity, hypercellularity in parabasal, and satellite cysts can affect the recurrence of OKC with odds ratios = 2.364, 2.364, 1.190, and 1.500, respectively). Conclusion: Gender (women), multilocular radiolucency, diffused inflammation in stroma, and mitosis in basal layer of epithelial lining, can statically predict the possibility of recurrence rate. In addition, findings regarding the age (in younger patients), corrugated surface, reverse polarity, and sub-basal cleft can be helpful in predicting recurrence.

Background: Dental anxiety has negative effects on dentists' pain management. Patients have different levels of pain tolerance. Therefore, providing psychological interventions can reduce treatment avoidance and promote oral health. This study compared the effect of acceptance and commitment therapy (ACT) and cognitive behavioral therapy (CBT) on pain coping strategies and pain perception intensity in patients with dental anxiety. Materials and Methods: This clinical trial with a pretest–posttest control group design and a 3-month follow-up period was performed on 45 patients with dental anxiety. They were randomly selected by convenience sampling method and assigned to two experimental groups and one control group. The first experimental group underwent 10 sessions of ACT, the second experimental group underwent 10 sessions of CBT, and the control group underwent oral care training. Data were collected by the Rosenstiel and Keefe's Coping Strategies Questionnaire and McGill Pain Questionnaire and analyzed by SPSS (version 24) software. The considered significance level is 0.05. Results: The results showed no significant difference between ACT and CBT in pain coping strategies and pain perception intensity (P < 0.05) but indicated a significant difference between the treatment groups and the control group. Moreover, the results showed a significant difference between posttest and follow-up and pretest in pain coping strategies and pain perception intensity (P < 0.01) but indicated no significant difference between posttest and follow-up (P < 0.05). Conclusion: ACT and CBT can play an important role in the sustainable improvement of pain coping strategies and pain perception intensity in patients with dental anxiety.

Ameloblastoma is a benign tumor of odontogenic epithelium which is slow growing, locally invasive, expansive that may result with asymmetries of the face. Conservative treatment of odontogenic tumors with marsupialization is not common but can be done successfully in those with cystic pattern. The aim of this case and literature review is to propose marsupialization as an initial procedure for its treatment. We have presented a case of an ameloblastoma involving 56-year-old male patient. Orthopantomography and computed tomography showed the lesion extended between the right molar region and left molar region of mandible with both buccal and lingual expansion and root resorptions. On clinical examination, expansions of mandible and slight tooth mobilities were seen. An incisional biopsy was carried out and histopathologic examination revealed ameloblastoma although clinical features of lesion were more suggestive of cyst. Our case was treated by obturator marsupialization with a good healing. This case and review of the literature discusses the available treatment option according to macroscopic features of jaw lesions and emphasizes on the importance of the most conservative treatment option. Conservative treatment preserves integrity of bones while radical treatment can leave major cosmetic and functional sequelae such as pathologic fractures, complication with reconstruction plates.

Background: General anesthesia in dentistry has been widely utilized in cases of uncontrollable fear/anxiety and uncooperative patients, patients of young age, and those allergic to local anesthesia and with other existing systemic diseases. These people usually require re-treatment owing to their weak immunity. Our study investigates the frequency and the prevalence of re-treatment in patients and candidates for dental procedure under general anesthesia in Isfahan during 1393–1396. Materials and Methods: The present cross-sectional study randomly chose 162 patients who were candidates for dental procedures. Patients who came in for re-treatment twice or more during this period were identified and their records were requested from the archives. Demographic data, reason for using general anesthesia, underlying disease, physical condition, and mental condition were all gathered through a questionnaire. The causative etiology of re-treatment was identified by examining the patients' medical records including restorations, denervation, tooth extraction, filling, and pulpotomy. Statistical analysis was performed using the SPSS software (version 25) and tests such as Kolmogorov–Smirnov Z-test, Spearman, and Chi-square test. P < 0.05 was considered statistically significant. Results: The findings of the present study showed that 92.25% of patients needed dental re-treatment during their second visit. The most needed treatment was in the second repair session and the least was related to prosthetics. It was also noted that 42.15% of patients needed dental treatment at the third visit and the highest need for treatment was in the third prosthesis session and the lowest reason was related to tooth restoration and extraction. Conclusion: The most needed treatment was in the second session of endodontic treatment, and in the third session, tooth extraction was one of the required treatments, which indicates the progression of dental problems in the interval between treatments.

Background: This study presented a cleaning method for orthodontic NiTi-closed coils and evaluated its effect on the force characteristics of these coils. Materials and Methods: In this in vitro study, 160 orthodontic NiTi-closed coils, 160 orthodontic NiTi-closed coils (9 mm) from two brands G and H and DB, randomly assigned into four groups. Group 1: Three times of immersion in the 10% hydrochloric acid (HCI) solution for 1 min followed by the immersion in 5.25% sodium hypochlorite solution for 5 min. Group 2: Three times autoclave sterilization. Group 3: Three times of immersion in 10% HCI solution for 1 min, followed by the immersion in 5.25% sodium hypochlorite solution for 5 min and autoclave sterilization. Group 4: No immersion and no sterilization. The forces of coils were measured at 25, 23, 21, 19, and 17 mm extension. To measure the force characteristics of coils, an electromechanical universal testing machine was used. For the statistical analysis, Kolmogorov–Smirnov, Kruskal–Wallis, and Mann–Whitney U-tests were used at 0.05 significance level. Results: In G and H coils, no significant differences between the mean forces of different groups were found in any extensions. In DB coils, only in 25 mm extension, there were no significant differences between the groups (P = 0.144). In 17-, 19-, and 21-mm extensions, significant differences (P < 0.001) were found like in 23 mm extension (P = 0.05). In both brands, more extension makes significant more forces statistically (P < 0.01). In all extensions, G and H coils have significant less forces (P < 0.001). Conclusion: Immersion in HCl, 10% for 1 min followed by the immersion in NaOCl, 5.25% for 5 min followed by autoclave sterilization, even three times repeating of this process, did not result in significant changes in the force characteristics of A-NiTi-closed coils.

Background: Infants and children who experience pain in early life, show long-term changes in terms of pain perception and related behaviors. Local anesthesia is integral to the practice of painless dentistry but the pain of injection itself is deterrent to successful administration of local anesthesia and can be a most anxiety-provoking procedure. Distraction as a behavior management technique is successfully known to reduce pain and manage children's dental behavior by diverting their attention away from painful stimuli during invasive dental procedure. This study aimed to compare the pain associated with local anesthetic injection delivered with and without the use of distraction as a behavior management technique in 6–8-year-old children. Materials and Methods: In this randomized, clinical, in vivo study with a split-mouth design we compared the pain of 30 children (6–8-year-old), requiring dental treatment necessitating the use of local anesthesia bilaterally in either of their maxillary and mandibular arches. Treatment was done in two visits, 1 week apart. Children were randomly assigned to receive the distraction (iPad) at one visit while no distraction in other visits. Two different pain assessment scales were used: Wong-Baker faces pain scale (FPS) and FPS-Revised. The Chi-square test was used for statistical analysis. P ≤ 0.05 was considered to be statistical significance. Results: Children who received local anesthesia with audiovisual distraction had lower pain rating scores than those who received local anesthesia with no distraction. Conclusion: Audiovisual distraction significantly reduces pain associated with injection of local anesthesia.

Background: Zinc oxide (ZnO) and graphene oxide (GO) nanoparticles (NPs) have antimicrobial properties. The present study was undertaken to evaluate the effects of incorporating these NPs and their chemical and physical blends on abrasion, translucency, and microhardness of flowable composite resin. Materials and Methods: In the present in vitro study, flowable composite resin samples (Grandio Flow, VOCO, Germany) were evaluated in 5 groups and the sample size was 10 for each group of each experiment (n = 10) as follows: Group 1, without NPs; Group 2, with ZnO NPs; Group 3, with GO NPs; Group 4, containing a physical mixture of GO and ZnO; and Group 5, containing a chemical mixture of GO and ZnO NPs. In all the groups, 1 wt% of the NPs were incorporate into flowable composite resin. Abrasion, translucency, and microhardness of the samples were evaluated. Data were analyzed with analysis of variance, followed by post hoc Tukey's tests at the level of significance of P < 0.05. Results: In Groups 2, 4, and 5 (all the groups containing ZnO), a significant decrease in abrasion and microhardness of flowable composite resin was observed compared to the control group. Incorporation of NPs in all the groups resulted in a significant decrease in translucency compared to the control group. Conclusion: Incorporation of NPs into flowable composite resin resulted in a decrease in translucency. The microhardness was reduced in groups containing ZnO, but the abrasion was also reduced in these groups. The incorporation of GO did not significantly alter the abrasion and microhardness of the composite resin.

Background: This study aimed to assess the microshear bond strength (micro-SBS) of two universal adhesives with different pH values in etch-and-rinse (E and R) and self-etch (SE) modes to superficial dentin. Materials and Methods: This in vitro experimental study evaluated 75 extracted sound human third molars. Superficial dentin was exposed by trimming the enamel and removing 0.5–1 mm of tooth structure beyond the dentinoenamel junction. A 600-grit abrasive paper was used to create smear layer. The teeth were randomly divided into five groups (n = 15). All-Bond Universal and G-Premio Bond were applied in E and R and SE modes in four groups. Clearfil SE Bond was used in the control group. Z350XT composite cylinders (0.9 mm diameter and 1.5 mm height) were then bonded to the prepared surface. The teeth were incubated at 37°C and 100% humidity for 24 h. Micro-SBS was measured by a universal testing machine, and the mode of failure was determined under a stereomicroscope. Data were analyzed using ANOVA, Bonferroni test, and Fisher's exact test (alpha = 0.05). Results: The micro-SBS of Clearfil SE Bond was significantly lower than all other groups (P < 0.05). All-Bond Universal yielded the maximum micro-SBS in SE and minimum micro-SBS in E and R mode. All-Bond Universal showed significantly lower micro-SBS in E and R mode than SE mode (P < 0.05). No other significant differences were noted. The mode of failure was also significantly different among the groups (P < 0.05). Mixed failure had the highest frequency in G-Premio in E and R mode. Conclusion: Type of adhesive and application mode affected the micro-shear bond strength to superficial dentin.

Background: Periodontitis, the second most common reason for tooth loss in adults, is a chronic inflammatory condition that increases the prevalence of cancer by inhibiting apoptosis and promoting tumor cell growth. However, it is still debatable if tooth loss is an important risk factor in oral cancer (OC). The aim of this systematic review is to analyze the relationship between tooth loss and the probability of developing head-and-neck cancer and also to see if there is an association between tooth loss, periodontitis, and the risk of OC. Materials and Methods: Studies that depicted a link between tooth loss and OC (till 2017) were searched from online databases accompanied by a thorough manual search of relevant journals. Data were collected from eligible studies, and meta-analysis was carried out using the Meta-Analysis software. The effect of various inclusions was assessed by sensitivity and subgroup analysis. Publication bias was also evaluated. Results: The meta-analysis consisted of 15 publications. When the number of teeth lost was counted, there was significant variability (I2 = 98.7%, P = 0.0001). When more than 15 teeth were missing in a subgroup analysis, there was a 2.4 times greater risk of OC (odds ratio: 2.496, 95% confidence interval [CI] = 2.067–3.015, P = 0.001) with no heterogeneity (I2 = 0.00%, 95% CI for I2 = 0.00–68.98). Subgroup analysis revealed that there was no evidence of publication bias. Conclusion: It was concluded that tooth loss can increase the OC risk by nearly 2 folds. However, large-scale population-based studies are needed to substantiate the findings.

Background: The aim of the current study was to evaluate the outcomes and complications of three-unit porcelain-fused-to-metal tooth-implant-supported prostheses in comparison with implant-supported prostheses. Materials and Methods: In this review article, the electronic databases, PubMed, Scopus, LILACS, Web of Science, EBSCO, LIVIVO, and Embase were searched over the past 20 years until December 2021. Risk ratio with 95% confidence interval (CI), fixed effect model, and Mantel–Haenszel method was calculated. The meta-analysis was performed with the statistical software Stata/MP v. 16. Results: Two hundred and three studies were selected for reviewing the abstracts, from which the full texts of 16 studies were reviewed. Finally, five studies were selected. The risk ratio of prosthesis failure between the tooth-implant-supported prosthesis and the implant-supported prosthesis was RR (Risk Ratio)= 1.83 (0.79, 4.24), (P = 0.16) and for prosthesis complication, it was RR = 0.61 (0.35, 1.06), (P = 0.08). Risk ratio of implant failure between the mentioned groups was RR = 2.33 (0.84, 6.41), (P = 0.10), and for implant complications, this rate was 0.09 (RR, 0.09 95% CI − 1.30, 1.48; P = 0.90). Conclusion: The meta-analysis of the present study showed that there was no significant difference between the two groups (three-unit porcelain-fused-to-metal tooth-implant-supported prosthesis and implant-supported prosthesis reconstruction) in terms of the total failure of implants and prostheses and the complication rate of implants and prostheses.

Background: The aim of the study was to compare the root reinforcement potential of different light cured intraorifice barriers (TheraCal, lime-lite, Ionoseal and resin-modified glass-ionomer [RMGI] [Fuji II LC]) with or without bonding agent placed in the orifice of endodontically treated and bleached teeth. Materials and Methods: In this experimental in vitro study, single-rooted bovine teeth were instrumented and obturated with gutta-percha. Except the control group, in other specimens, gutta-percha was removed 3 mm under cementoenamel junction. Then, the specimens were divided into seven groups according to the bases was applied: TheraCal LC, TheraCal LC with bonding agent, Lime-Lite, Lime-Lite with bonding agent, Ionoseal, Ionoseal with bonding agent, and RMGI (Fuji II LC). After internal bleaching, the teeth were decoronated. Then, all the groups were subjected to fracture resistance testing using Universal Testing Machine. For evaluating fracture resistance, analysis of variance and Tukey's test were used and for comparing the mode of fracture fisher test was applied in SPSS software. The significance was determined at (α = 0.05) confidence interval. Results: The group of TheraCal LC with bonding agent showed better fracture resistance as compared to the control group (P = 0.004). Although there was no statistically significant difference in the pairwise comparison between the other groups. Conclusion: TheraCal LC with bonding agent can be used as intraorifice barriers with good fracture resistance in endodontically treated and bleached teeth.

Background: The use of photodynamic therapy (PDT) has been evaluated as an adjunctive technique for bacterial decontamination of implants with peri-implantitis. Given the controversies over the efficacy of the application of PDT to treat peri-implant diseases, the present clinical study aimed to evaluate the posttherapeutic clinical parameters and cytokine levels in peri-implant crevicular fluid in patients with peri-implant mucosal inflammation, receiving mechanical debridement (MD) alone or in association with PDT. Materials and Methods: In this double-blinded randomized clinical trial, 52 patients with peri-implant mucosal inflammation were selected and they were randomly assigned to 2 treatment groups: a MD group and an MD + PDT group using an 805 nm laser and indocyanine green (ICG). Although the decrease in bleeding on probing was the primary outcome, pocket depth, PUS, pain on probing, clinical attachment level, gingival recession, tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and matrix metalloproteinase-8 were also evaluated at baseline, 2-week, and 3-month postintervention. Repeated measure analysis of variance was used to analyze inter-group differences and a P ≤ 0.05 was considered for significant differences between tested parameters. Results: Statistically significant improvements (P < 0.001) were detected for all variables after comparison of baseline data with those collected at each time interval of the study. Nevertheless, the inter-group comparisons of these variables between the baseline, 2-week, and 3-month intervals did not reveal any significant decrease in sites treated with either MD alone or MD + PDT. Conclusion: The application of PDT using 805-nm laser and ICG as an adjunct therapy to MD did not provide any additional improvements in the clinical or biologic parameters of peri-implant mucosal inflammation.