Effect of Galardin and its Solvents on the Microtensile Bond Strength of Different Adhesive Systems to Dentin

Objective: To evaluate the effect of a synthetic inhibitor of MMPs (Galardin) and its solvents [ethanol and dimethyl sulfoxide (DMSO)] on the microtensile bond strength (µTBS) of adhesive systems to dentin. Material and Methods: Sound human third molars (n=180) were randomly assigned into 5 based on solution type: DMSO; ethanol; Galardin + DMSO; Galardin + ethanol; and distilled water as control. Then were further subdivided into 6 based on the adhesive system, i.e. 3-step and 2-step etch-and-rinse (ER), one-step and 2-step self-etch (SE) and universal in ER and SE strategies. The samples underwent a 500-round thermocycling procedure at 5±5/55±5°C and were sectioned into 1-mm2 pieces perpendicularly in a cutting machine. The µTBS was measured at a strain rate of 1 mm/min. Data were analyzed with two-way ANOVA and post hoc Games-Howell tests (p<0.05). Results: The adhesive system and the solution had significant effects on the µTBS (p<0.001). The universal adhesive in the SE mode resulted in a significant decrease in µTBS compared to the other adhesives (p<0.05). Ethanol, too, resulted in a significant decrease in µTBS compared to other solutions (p<0.05). Conclusion: Galardin and its solvents, except for ethanol, had no detrimental effects on the immediate µTBS.

Inhibitory Effect of Gamma-Secretase on the Survival Rate of Dental Pulp Stem Cells: An in Vitro Study

Objective: To evaluate in vitro the effect of gamma-secretase inhibition on the survival of dental pulp stem cells. Material and Methods: Sound teeth have been used. Dental pulp stem cells were isolated by enzymatic digestion. An appropriate number of cells were treated with different concentrations of gamma secretase enzyme (DAPT) (1, 3, 6.25, 12.5, 25.5, 37.5, 50 and 100 µM). The metabolic activity of cells and the distribution of cells in different phages of cell cycle was evaluated by MTT assay and flow cytometry, respectively. Statistical analysis was made one-way ANOVA. Comparison was made between the groups on the level of p<0.05. Results: In low concentration of DAPT (1, 3, 6.25, 12.5) the growth rate of the cells increases, whereas in high concentration of DAPT (25.5, 37.5, 50, 100) can significantly reduce the viability of the treated cells. The results also indicate that DAPT can interrupt the cell cycle in G1 phase. Conclusion: The DAPT for dose-dependent survival rate of dental pulp stem cells and affect cell population increase in the G1 phase of the cell cycle.

Comparison of the Accuracy of Digital Radiography with Conventional Radiography and Visual Examination in the Detection of Permanent Teeth Interproximal Caries

Objective: To compared the accuracy of digital radiography in the diagnosis of interproximal caries in permanent teeth with conventional radiography and visual examination. Material and Methods: In this descriptive-analytical study, 78 human premolars, which seem normal in primary examination, are mounted on the plaster in a pair-wise manner and their caries are visually evaluated. Conventional and digital radiographic images are taken under the same conditions and their caries are graded with Confidence Score. To determine the golden standard, after mesiodistal incision, the teeth are examined using stereomicroscopy. Finally, the results obtained by visual observation and conventional radiography as well as digital images were compared with those obtained from the stereomicroscopy to determine their accuracy in detecting the interproximal caries. Results: The consistencies between the visual, digital, and conventional methods with the standard method (microscopic histology) are 53%, 78%, and 50% respectively - all of them are significant (p<0.05). The highest and the lowest sensitivities are related to the digital (96%) and visual (88%) methods respectively, while the highest and lowest specificities are related to the digital (79%) and conventional (50%) methods respectively. The highest and lowest positive predictive value is related to the digital (79%) and conventional (80%) methods respectively. The highest and lowest negative predictive values are related to the digital (90%) and visual (71%) methods respectively. Compared with the standard methodology, the most accurate diagnostic accuracy can be seen for the digital method (91%). Conclusion: There is no significant difference in the diagnosis of interproximal caries by different methods, and the only advantage of digital radiography, compared with the conventional one, is storing radiographs without losing important information and the lower dose of radiation for the patient.

Comparing the Clinical Success Rate of Self-Drilling and Self-Tapping Mini-screws in the Retraction of Maxillary Anterior Teeth

Objective: To compare the success of self-drilling and self-tapping methods in the retraction of maxillary anterior teeth. Material and Methods: The study was conducted in 57 subjects with Cl II malocclusion who needed to be treated with extraction of four maxillary teeth. The selftapping method was used on the left side and the self-drilling method was used on the right side. Then, the pain rate of each method was recorded by the numerical rating scale (NRS). Statistical analysis was done by t-test and Chi-square test. The significance level in this study was considered at p-value<0.05. Results: Considering the clinical mobility as the failure, the success of treatment was equal in both methods and was 93%. The inflammation around the mini-screws was 8.8%. A significant relationship was found between the variables inflammation and success (p<0.05). The mean pain was 2.47 but there was no significant difference between the two methods in terms of pain score (p>0.05). There was a significant difference between the groups (p=0.03). The pain was significantly higher in the female. Conclusion: There is no difference between self-drilling and self-tapping methods in terms of success. Comparison of the pain between two genders according to the replantation method showed a significant difference in pain sensation between two genders. The pain sensation mean in female group was greater than male group.

Effect of Pharyngeal Pack on Postoperative Nausea and Throat Pain in Patients Undergoing Rhinoplasty

Objective: To evaluate the effect of pharyngeal pack on postoperative throat pain and nausea in rhinoplasty patients. Material and Methods: Twenty-eight patients were randomly selected and divided into two groups (n=14). The participants were randomly divided into two groups: G1 - the pharyngeal pack was used (Intervention group) and G2: not used (Control group). Both groups were anesthetized by the same protocol. Throat pain was measured by visual analog scale and nausea by presence / absence. Fischer's exact test, ANOVA, Friedman and Wilcoxon test were used. Results: There was no significant difference in mean pain and presence or absence of nausea between the two groups (p>0.05). But there was a significant difference in mean pain and the presence or absence of postoperative nausea with the intervals (p<0.05). Mean pain had a significant difference 2 hours postoperatively with other times, 6 hours postoperatively with 24 and 72 hours postoperatively, and 24 hours postoperatively with 72 hours (p<0.05). There was no significant difference in the presence or absence of postoperative nausea, between 2 hours and 6 hours postoperatively (p>0.05). The presence or absence of postoperative nausea had a significant difference between 2 hours postoperatively with 24 and 72 hours postoperatively and 6 hours postoperatively with 24 and 72 hours postoperatively (p<0.05). There was no significant difference in nausea between 24 hours and 72 hours postoperatively (p>0.05). Conclusion: None of the two groups were significantly superior in terms of reduction of pain and nausea, but because of the possible effectiveness of the pharyngeal pack in preventing aspiration of objects and tissues during the operation, the use of pharyngeal pack is recommended in patients.

Dimensional Stability of Casts Derived from Three Types of Alginate at Different Times After Impression

Objective: To evaluate the dimensional changes in three types of alginate following three different delay times after casting. Material and Methods: In this laboratory study, a maxillary arch-shaped stainless steel model was prepared and three pins with similar and determined diameters and heights were placed (one at mid-line and two on the underside of the model) as reference points to compare the dimensional stability of the three types of alginates. A special metal tray was made from the main model. The main moldel was imprisoned by the metal tray, and these were kept for a specific time in a humid environment. Gypsum Type 4 was poured over the impression to obtain 90 gypsum casts for three types of alginate. The dimensions of casts obtained from each alginate were compared in two lateral and anterior-posterior dimensions, they were compared with each other, and the alginates were also compared to the main model. Results: At a time interval of 15 minutes, the dimensional accuracy of the casts obtained from the three types of alginates, with the main model in both anterior-posterior and transverse dimensions was not significantly different (p<0.05); but there was a significant difference at 60 minutes and 24 hours in both dimensions (p<0.05). Although there was no significant difference between the alginates in both dimensions and all three studied time periods, the least difference with the main model was related to Zhermack and the highest difference was related to Golchai alginates. Pairwise comparisons showed that none of the samples had a significant difference in terms of dimensions. Conclusion: The dimensional stability of alginate was a time-dependent type of alginate and had no significant effect on the dimensional accuracy of casts.

Evaluation of Periodontal Status of Adjacent Teeth to Posterior Single- Tooth Implant during a One-Year Period after Restoration: A Cross- Sectional Study

Objective: To evaluate the periodontal status of teeth adjacent to the posterior single tooth implant during one year after restoration. Material and Methods: In this crosssectional study, 36 patients, which were systematically and had received the implant(s) of single posterior teeth over the past year were selected. The teeth adjacent to singleposterior tooth implants were evaluated regarding bleeding on probing, mobility, gingivitis and periodontal pockets during the follow up period of 3, 6 and 9 months under the supervision of two specialists. To investigate the relationship between periodontal statuses, the Chi-square test was used, and the Kruskal-Wallis test was used to assess statistical significance of periodontal indexes in the period under assessment. The p-value of less than 0.05 was considered significant. Results: There was no significant relationship between the variable of bleeding on probing, mobility, gingivitis and periodontal pocket in the studied distal and mesial teeth. Out of studied patients, after 9 months, only 11.1% had one of the periodontal problems, as a result, 88.9% of crowns replacement of single-posterior tooth does not make any periodontal damages to adjacent teeth. Conclusion: Crowns replacement of implant does not have any destructive impact on periodontal condition of adjacent teeth.

Efect of Anaheal (Bromelain) Drug on the Periodontal Clinical Indices in Nonsurgical Periodontal Treatment of Patients with Chronic Periodontitis

Objective: To evaluate the effect of Anaheal (Bromelain) drug on the periodontal clinical indices in nonsurgical periodontal treatment of patients with chronic periodontitis. Material and Methods: In this double blind clinical trial, 80 patients with chronic moderate periodontitis and a healthy systemic status were chosen, and divided into two 40-subject groups. Thereafter, the standard treatment of periodontitis including scaling and root planning in one session by the unit operator was performed for all patients. Eventually, one group of the patients was administered Bromelain medication (500-mg capsule twice a day) one hour before food, while the other group was given placebo. Four and eight weeks after the treatment, the clinical periodontal indicators were measured and recorded in both groups. The data were assessed using descriptive statistics and analytical test methods (Mann-U-Whitney and Chi-square). P value less than 0.05 was considered statistically significant. Results: Gingival index, probing depth and plaque index before the treatment were similar in both groups (Anaheal and placebo). However, four and eight weeks after the treatment, the three studied indices were significantly lower in the Anaheal group as compared to the placebo (p<0.05). The index of bleeding on probing was also similar before the treatment and four weeks after the treatment in both groups. However, eight weeks after the treatment, this index was significantly lower in the Anaheal group as compared to the placebo group (p<0.05). Conclusion: Administration of oral Anaheal medication after nonsurgical periodontal treatments reduced all the clinical periodontal indices among patients with chronic periodontitis as compared to the control group. Therefore, it can be a suitable substitute for the common oral industrial antibiotics.

Effect of Consecutive Removal and Placement of Abutments during Prosthetic Procedures on an Increase in Proinflammatory Cytokine Levels around Dental Implants

Objective: To evaluate the effect of repeated removal and placement of abutments during prosthetic stages on increasing proinflammatory cytokine levels around dental implants. Material and Methods: All the patients with dental implants, referring to the prosthodontics private office during a 3-month period, were examined in relation to the health of the implants and included in the present study based on inclusion criteria; the patients had a multi-unit abutment on one side of the jaw and a conventional healing abutment on the implant on the other side of the jaw. Samples of gingival crevicular fluid were taken from all the eligible subjects for immunological analyses. The samples were taken from the sulcus around each implant in each subject. The samples were sent to the immunology laboratory for determination of IL-6 and IL-1ß proinflammatory cytokines with the use of an ELISA kit. Data were analyzed with SPSS 16 and Descriptive statistics and T-test was used. Statistical significance was set at p<0.05. Results: The results showed that the mean concentrations of IL-1ß and IL-6 in the group with multi-unit abutment were less than those in the conventional abutment group. In addition, comparison of the means of IL-6 and IL-1ß concentrations showed that in both groups the concentration of IL-6 was higher than that of IL-1ß. Conclusion: The use of multi-unit abutments resulted in less inflammation compared to the use of conventional two-segment abutments, which require repeated removal and placement during the prosthetic stage.

Effect of Home Bleaching on the Color Matching of Composite Resin Restorations

Objective: To investigate the effect of home bleaching on color matching between the dental restoration and the adjacent tooth structure after the staining process. Material and Methods: Ten intact maxillary central incisors were used. After preparation (semimesial restoration of the specimens), the specimens were immersed in a colored solution for 14 days and then were washed and the bleaching process was there after performed. A spectrophotometer apparatus was used to determine the color of the specimens in the part of the tooth filled with restorative material three times, including before the staining process, fourteen days after the staining process and immediately after the bleaching process. Paired t-test was employed to compare the color of the intact tooth and the dental restoration before and after the staining and bleaching processes. The level of significance was set at 5%. Results: Pre-bleaching E color of the teeth was 68.1, which increased to 78.8% after bleaching, and this increase was also statistically significant (p<0.001). Pre and Post-bleaching E color of composite restorations was 65% and 77.6%, respectively. This increase was also statistically significant (p<0.001). Postbleaching E color of the tooth and composite material was 78.8% and 77.6%, respectively. This difference was not statistically significant (p=0.342). Conclusion: The staining and bleaching processes had a significant effect on the discoloration of the dental restoration and the tooth; however, the application of bleaching on the teeth and composite improved the tooth composite color-match.

Evaluation of the Color Matching of Composite Resin Restoration used for Repair with Initial Composite Resin Restoration

Objective: To investigate the color matching of the composite resin used for repaired with initial composite resin restoration after the aging process. Material and Methods: After preparation of 30 composite resin samples, their color were determined using the spectrophotometer four times and the average was recorded. After the initial aging, the color of the samples was measured again. Then, the repair process was performed with an appropriate composite resin color for each sample and the aging process was performed again. After the second aging, the color of the initial and the repaired composite resins were measured. Then, the data were analyzed by paired T-test. The level of significance was set at 5%. Results: The color difference of the initial composite resin between before and after initial aging, as well as the color difference of repaired composite resins between before and after second aging, were significant (p<0.001). Also, after the second aging, the color difference between initial and repaired composite resin restoration were significant (p<0.001). Conclusion: The color matching of the repaired composite resin with the initial one is not acceptable. In this way, replacement of initial composite suggested instead of repaired.

Comparison of Digital Diagnostic Value and Cone Beam Computed Tomography (CBCT) in Determining Vertical Root Fracture in Single- Root Teeth

Objective: To compare the accuracy of digital radiography and CBCT for the diagnosis of vertical root fractures in single root teeth. Material and Methods: For this descriptive-analytic study, 50 non-fractured, single-root teeth were selected. The teeth were randomly divided into a control and an experimental group (25 teeth in each group). The teeth in the control group did not have vertical root fractures. In the test group, after preparing the access cavity, the root canal was cleared and loosened up to No. 80 file, then a vertical root fracture was created by one of the K-Reamers Nos. 90- 130.The images were prepared by CBCT radiography in axial and cross-sectional slices and in digital radiography with PSP sensors at mesial, distal, and parallel angles. The Chi-square test was used to express the correlation of variables. Results: In the diagnosis of vertical root fractures, the sensitivity of CBCT in the axial section was 32% and in the cross-sectional slice it was 20%, whereas the specificity in both the sections was 100%. The sensitivity of the digital radiography in detecting vertical root fractures for parallel, mesial, and distal angles was 38%, 16%, and 24%, respectively. Conclusion: According to this study, the sensitivity, specificity, and accuracy of digital radiography and CBCT were not significantly different.

Effect of Sequential Use of 0. 2% Chlorhexidine Mouthwash and Listerine on Microbial Plaque Control

Objective: To evaluate the effects of combined and sequential consumption of chlorhexidine and listerine mouthwashes on plaque indices. Material and Methods: Sixteen dental students, both genders, were selected. After prophylaxis, four mouthwash regimens were used, such that in each period, mouthwash was used for 5 days and after each period there was 4 days of washing out. During the mouthwash period, the participants did not use any mechanical plaque control tool. The four regimens included: first regimen, first chlorhexidine then listerine; second regimen, listerine then chlorhexidine; third regimen, only listerine; fourth regimen, chlorhexidine alone. At the end of the period, individuals were evaluated for plaque indices and investigated for bleeding during probing using ANOVA variance analysis and post-hoc Tukey test. The level of significance was set at 5%. Results: Regimen 1 with a plaque mean of 0.55 ± 0.25 had significantly lower plaque than other regimens. The maximum rate of plaque was observed in regimen 3. Probing did not cause bleeding in any of the individuals who used the four mouthwash regimens. Conclusion: The use of 0.2% chlorhexidine and listerine has the highest effect on plaque reduction.

Frequency of Post-Operative Sensitivity in Class II Composite Restorations in Iranian Patients

Objective: To determine the frequency of sensitivity after treatment in composite resin restorations Class II of premolars in Iranian patients. Material and Methods: In this descriptive-cross-sectional study, questionnaires were used which included questions about the extent of post-operative sensitivity in posterior composite resin restorations among 178 patients referred to the restoration section. After restoration of the teeth, the patients were called to record sensitivity after the treatment. Post-operative sensitivity was measured 24 h and 1 month with cold stimulation using Visual Analog Scale (VAS) method. The data were analyzed with the SPSS software, through descriptive statistical methods (frequency and percentage, mean, standard deviation). Group comparisons were evaluated using Mann-Whitney U test and p-value <0.05 was considered to be statistically significant. Results: The mean frequency of sensitivity in terms of gender was 0.75 and 0.76 in males and females, respectively. The mean frequency of sensitivity in terms of type of jaw was 0.59 and 1.1, in the upper and lower jaw, respectively. It was also observed that the frequency of sensitivity is higher in adolescent age group, in comparison with other age groups. No significant association between gender as well as type of jaw and post-operative sensitivity frequency was observed (p>0.05). However, age group has a statistically significant association with the frequency of post-operative sensitivity (p<0.05). Conclusion: There is a significant relationship between extent of sensitivity after treatment in composite resin restorations Class II and the age group of patients.