Background: Small chipping or fracture of ceramic restorations may be repaired by composite resin instead of replacing the restoration. This method is faster and cheaper compared to restoration replacement. Several strategies have been suggested to obtain a high repair shear bond strength (SBS). This study aimed to assess the efficacy of some new ceramic surface treatments (laser and universal adhesive) to enhance the repair bond strength of composite resin to ceramic compared to the conventional method. Materials and Methods: This in vitro study evaluated 80 IPS Empress Esthetic ceramic plates in eight groups (n = 10). The ceramic surface was polished with 320-grit silicon carbide paper under running water, rinsed with water spray for 10 s and dried. The samples were then divided into two subgroups for mechanical surface preparation with hydrofluoric (HF) acid and Er: YAG laser (2 W, 200 m J, 10 Hz, 10 s). Each group was divided into two subgroups for use/no use of silane. The conventional or universal adhesive was then applied on the samples in each subgroup. Composite cylinders were bonded to the ceramic surface using plastic tubes. The samples were stored in distilled water at 37°C for 24 h and subjected to an SBS test. Data were analyzed using one-way ANOVA (P < 0.05). Results: The interaction effect of variables on SBS was significant. Maximum SBS was noted in HF acid + silane + conventional adhesive group (mean: 12.0481 MPa). Minimum SBS was noted in the laser + conventional adhesive group (mean: 2.5766 MPa). Surface treatment with HF acid yielded significantly higher SBS than laser (P < 0.001). The interaction effect of conventional/universal adhesive and use/no use of silane on SBS was statistically significant. Conclusion: The repair SBS was higher in groups treated with HF acid compared to laser. Ceramic surface treatment with HF plus silane plus conventional adhesive yielded a higher SBS as well as HF plus Universal adhesive. Thus, the application of silane as a separate step can be omitted in the repair of ceramic restorations with universal adhesives.

The white spot lesion on the dental enamel is an optical alteration that compromises the esthetics of smile. It can be caused by many factors, among them, defects in mineralization and formation of tooth enamel. Resin infiltrants are agents that penetrate, by capillarity, through the pores of the demineralized or hypomineralized enamel, altering the refractive index (RI) of the tooth structure and totally or partially masking the appearance of the white spot. The aim of this work was to report the use of resin infiltration to minimize the visualization of white spot lesion, present in an upper central incisor, as a microinvasive approach for the esthetic treatment of deep enamel hypomineralization. A 20-year-old female patient sought care with the esthetic complaint of extensive white spot lesion on the buccal face of her upper right central incisor. The diagnosis established was a deep white stain associated with the incisor molar hypomineralization syndrome, and the treatment of choice for the resolution of the case was the application of the Icon^® resin infiltrant (DMG, Hamburg, Germany). To reach the body of the lesion, three cycles of acid erosion, using 15% HCl, were necessary to obtain a satisfactory aspect of masking the white lesion. A camouflage effect of the deep white spot lesion was achieved with the use of the resin infiltration, without the need of additional and irreversible wear of the dental structure.

Background: To compare and evaluate the strength rendering capacity of three restorative materials in tooth model simulated as immature teeth. Materials and Methods: In this in vitro study, 80 human maxillary permanent central incisors scheduled for periodontal extraction were collected, and an immature tooth model was prepared using a 3 mm twist drill. To simulate single-visit apical barrier, all the teeth were prepared with peso number 1–6. The teeth were segregated into three experimental and a control group. The experimental groups (n = 20) comprised of fiber-reinforced composite (FRC), Biodentine, and glass ionomer cement. The fracture resistance of all the teeth was tested using universal testing machine. The final reading of the applied load to cause fracture was noted and later was subjected to statistical analysis, P ≤ 0.05 was considered statistically significant, and the level of significance was fixed at 5%. Student's t-test was applied to compare values among experimental groups Results: There was a significant difference in the values of peak load resulting in fracture among experimental groups which was observed statistically (P ≤ 0.001). FRC exhibited superior reinforcing capacity (mean: 1199.7 N) among the experimental materials followed by Biodentine and Bioglass R. The lowest value to fracture was observed in control group (mean: 236.7 N). Conclusion: The results indicate that FRC could substantially contribute positively in reinforcing the simulated thin-walled immature roots.

Background: To compare the effect of different mouth washes on metallic ions release from silver-soldered and laser-welded orthodontic attachments. Materials and Methods: In this comparative in vitro study, 32 samples of molar bands without attachments were used. Sixteen samples were silver soldered to stainless steel (SS) wire and 16 samples were laser welded using laser welding device to SS wire. Each group samples were divided into four test groups and submerged in solution containing sodium fluoride (NaF), NaF + alcohol (NaF + alcohol), Chlorhexidine (CHX), and artificial saliva (AS). Samples were shaken for 24 h with an agitation rate of 60 rpm. One sample from each group was selected to study the morphologic changes on their surfaces through scanning electron microscopy (SEM), and remaining samples were studied for metal ions released and dissolved in the solutions using spectrometry. The metal ions release values of two different attachment methods in three different mouth washes and AS group were compared using the unpaired t-test. A two-way analysis of variance was used to identify the significant differences between the two types of orthodontic attachments immersed in four different types of solutions. P < 0.05 was defined to be set significant for all tests. Results: Level of metal ions released from the samples of silver soldering was higher than from laser welding. The lowest amounts of metal ions were released in CHX while highest in NaF + alcohol. The SEM images were in accordance with these findings. Conclusion: Laser welding should be preferred over silver soldering for the construction of orthodontic appliances. CHX containing mouthwashes such as Hexidine can be prescribed for the patients undergoing orthodontic treatment. More in vivo experiments will determine whether the levels of dissolved nickel ions can reach the toxic or sub-toxic concentrations or not.

Background: During the first experiences of clinical treatment, dental students face various challenges. The purpose of the study is to standardize the questionnaire as a suitable tool for quantitative and qualitative evaluation of psychosocial impact, stress levels, and learning effect of dental students during the transition from preclinical to clinical education in Persian. Materials and Methods: In this cross-sectional study a questionnaire including three areas of psychosocial impact, perceived stress, and learning effect was systematically translated. In the group of experts, face validity was examined. Then, the content validity ratio (CVR) and the content validity index (CVI) were determined. The reliability of the questionnaire was determined by the test–retest method and the Cohen's Kappa coefficient. In a cross-sectional study, the psychosocial impact, stress levels, and learning effect of all students newly admitted to the endodontic, prosthetics, periodontics, and restorative dentistry departments of Shahid Beheshti Dental School (128 people) were measured. Mann–Whitney and Spearman–Rho were used for statistical analysis (P = 0.05). Results: During the CVR and CVI evaluation, 12 statements were removed from the questionnaire, and one statement was changed. All valid statements of the questionnaire were considered reliable. The initial questionnaire was finally developed in the form of 27 items. Interest in clinical treatment and collaboration between students and faculty had the greatest psychosocial effects. The highest level of stress among students was seen in the endodontic ward (mean = 3.8). The greatest effect of learning was seen in different sections in infection control (mean >4). Conclusion: This study provided a standardized tool in Persian to evaluate the psychosocial impacts, perceived stress, and learning effect of dental students during the transition to clinical education and focused on the first clinical treatment experiences. One important psychosocial factor was collegiality between teachers and students. The ability to communicate well with the patient is thought to reduce stress.

Background: To establish an endodontic diagnosis, a clinician should consider a variety of factors. Various studies have failed to demonstrate a strong correlation between histological findings with clinical and radiographic assessments. This study sought to evaluate the histopathological features of reversible and irreversible pulpitis diseases and their correlation with clinical diagnosis in extracted human molar teeth. Materials and Methods: In this experimental ex vivo study, 75 molars with caries and three intact molars were used. According to the radiographic findings and clinical criteria and the need for root canal therapy, samples were categorized as having normal/reversible pulpitis and irreversible pulpitis. Immediately after extraction, an exposure was made at 2 mm below the cementoenamel junction. Formalin-fixed specimens were decalcified, sectioned and stained with hematoxylin and eosin for histological examinations using light microscopy. Variables including the type and severity of the inflammation, hyperemia, necrosis, fibrosis and the existence of an odontoblastic layer and dentin bridge were evaluated. The Fisher's exact test and the Chi-squared test were used for statistical analysis. P <0.05 was considered as significant. Results: Acute inflammation, hyperemia and pulp exposure were significantly more common among subjects with irreversible pulpitis (P < 0/005). However, fibrosis was significantly higher in the reversible group (P < 0/005). There were no statistically significant differences between the groups regarding the other variables. Conclusion: Some discrepancies between clinical, radiographic and histological findings were observed in our experimental study. Indeed, effective clinical practice requires consideration of all discrepancies found.

Background: This study aimed to assess the oral health knowledge, attitude, and performance of the parents of autistic 3–12-year-old. Materials and Methods: This descriptive cross-sectional study evaluated 50 parents of autistic 3–12-year-old in Isfahan city. The oral health knowledge, attitude, and performance of the parents were evaluated using a self-administered questionnaire with closed questions, after confirming its validity and reliability. Data were analyzed using independent t-test, one-way ANOVA, Pearson's correlation coefficient, regression analysis, and Cronbach's alpha (α =0.05). Results: Of children, 32 (64%) were males and 18 (36%) were females. A total of 28 (56%) fathers and 22 (44%) mothers participated in this study. The mean age of the children and parents was 8.12 ± 2.4 years and 39.6 ± 6.8 years, respectively. The mean age at the time of diagnosis of autism was 4.08 ± 1.33 years. Of all children, 24 (46.2%) had a previous dental history. The mean scores of the knowledge and attitude of the parents were 5.2 ± 1.7 out of 11, and 16.1 ± 3.1 out of 30, respectively. Of demographic variables, order of child birth had a significant correlation with attitude of the parents, and those with one single child had significantly higher attitude score (P = 0.03). Conclusion: The oral health knowledge, attitude, and performance of the parents of autistic children in Isfahan city were lower than expected, which calls for knowledge enhancement strategies in this respect.

Background: This study aimed to compare the antimicrobial effects of green tea, microwaving, cold boiled water, and chlorhexidine (CHX) on Streptococcus mutans and Candida albicans on silicone pacifiers. Materials and Methods: In this in vitro experimental study, 60 equal-size samples of silicone pacifiers were cut, ultraviolet sterilized, and randomly divided into two groups (n = 30) for immersion in 0.5 McFarland standard suspension of S. mutans and C. albicans. The samples in each group were then randomly divided into five subgroups (n = 6) for disinfection with 0.12% CHX, cold boiled water, green tea, microwaving for 7 min, and distilled water. The sample suspensions were cultured on blood agar (for S. mutans) and Sabouraud dextrose agar (for C. albicans) and incubated. The number of colonies was counted after 24 and 48 h. Data were analyzed using the Kruskal–Wallis and Mann–Whitney tests (P < 0.05). Results: At 24 and 48 h, the S. mutans colony count was the lowest in CHX and green tea subgroups followed by microwave, cold boiled water, and distilled water subgroups (P < 0.05). Conclusion: CHX and green tea can significantly decrease the S. mutans and C. albicans colony count on silicone pacifiers.

Background: One of the critical factors determining the success of dental implants is primary stability. This study aimed to determine the density of jawbones in the implant candidate sites via cone-beam computed tomography (CBCT) and its correlation with the values obtained from resonance frequency analysis during surgery. Materials and Methods: In this descriptive-analytic study seventeen implant sites requiring implant placement were selected. Impressions were sent to the laboratory to construct a surgical guide via the stereolithographic method. An electronic surgery was performed on the chosen implant sites according to each patient's CBCT information entered into the Kaveh surgical guide software. The bone density of the target areas was calculated using the gray value (voxel value). After preparing the final osteotomy, an implant was installed in the area according to the manufacture's recommendation. The relevant Osstell^® SmartPeg was selected and installed on the implant body to determine the primary stability. Kolmogorov–Smirnov test and the correlation pearson correlation statistical test. used for statistical analyze. P value amounts < 0.05 was considered significant. Results: The mean and standard deviation of the gray scale in this study were 563.7 ± 218.8 and 65.3 ± 7.7 implant stability quotient (ISQ) respectively. The correlation between gray scale and ISQ was evaluated by the Pearson correlation test, and the results indicated a strong correlation between the two variables. Conclusion: The voxel value and primary stability had a normal distribution and strong correlation. In other words, the gray scale determined by CBCT imaging techniques at the proposed implant site could be used to assess the bone density before the surgery.

Background: Adverse pregnancy outcome is due to deviation from the normal physiological and immunological process. There is conflicting evidence in support of maternal periodontitis as a risk factor for preterm low birth weight (PTLBW). Thus, the aim of the present study is to evaluate the correlation between PTLBW and periodontitis in postpartum mothers based on clinical and microbiological parameters. Materials and Methods: An observational retrospective study was conducted. A total of 103 women with singleton births were included in the study, which was divided into two groups, i.e., Group I-PTLBW and Group II-normal term normal birth weight (NTNBW). Clinical parameters such as oral hygiene index simplified, gingival bleeding index (BOP %), periodontal probing depth (PPD) and and clinical attachment loss (CAL) were recorded on the next day of postpartum. Two samples from each group, i.e., placental extract and the subgingival plaque were collected and transported to the laboratory in an anaerobic medium for microbiological analysis. The statistical analysis was performed using an unpaired t-test and Wilcoxon Mann–Whitney U-test. The P < 0.001 was considered statistically significant. Results: PTLBW group showed significantly higher amounts of periodontal destruction in terms of clinical parameters. The pathogens were also in higher quantities in the PTLBW group compared to the NTNBW group. Conclusion: Periodontitis is related to PTLBW in pregnant women of the studied population. Maternal oral hygiene status delivering PTLBW babies are compromised compared to mothers delivering NTNBW babies. Hence, periodontitis during pregnancy phase is an important health concern for the growing fetus.