Dental Research Journal最新文献

Background: Tooth bleaching sensitivity (TBS) after bleaching procedures is a common problem. This study was undertaken to determine the effect of preoperative systemic capsaicin on tooth sensitivity (TS) after in-office bleaching procedures.

Materials and methods: Thirty participants received the treatment in this clinical trial. The subjects were randomly assigned to two groups (n = 15). Placebo and 0.25% capsaicin were administered three times daily for 24 h, with the first dose being administrated 1 h before the bleaching procedure. The subjects underwent two bleaching sessions at a 2-week interval by applying 40% hydrogen peroxide gel on six upper anterior teeth. A visual analog scale (VAS) was used to evaluate TS. Data were analyzed with SPSS 24. Statistical analyses were carried out with the Wilcoxon test and paired t-test. Statistical significance was set at P ≤ 0.05.

Results: In the capsaicin group, there was a significant increase in TBS between the immediate and 1-h postoperative intervals and a significant decrease between 1- and 24-h postoperative intervals (P = 0.01 and P = 0.000, respectively). In the placebo group, there was a significant decrease between immediate and 24-h and between 1- and 24-h postoperative intervals (P = 0.007, P = 0.02). Milder TS was detected in the placebo group 24 h after bleaching (P < 0.05).

Conclusion: Under the limitations of this study, preoperative use of systemic capsaicin did not significantly affect TS after the in-office bleaching procedure.

Background: Gingival enlargement (GE) is a common clinical observation among orthodontic patients, yet its underlying causes remain unclear. This study aims to investigate the potential involvement of salivary matrix metalloproteinase (MMP)-2 and MMP-9 activity in orthodontic-induced GE.

Materials and methods: In this case-control study, we enrolled 50 subjects, including 25 individuals with GE and 25 without. The participants, aged 10-35 years, were in the 4^th or 5^th month of their orthodontic treatment. Comprehensive clinical assessments, encompassing plaque index, gingival index, and GE score were performed, and saliva samples were subjected to gelatin zymography to assess enzyme activity. Statistical analysis, including the Chi-square test for age distribution, independent samples t-test for age comparison between study groups, Mann-Whitney U test for MMP activity comparison, and Wilcoxon signed-rank test for comparison of data from the 4^th to 5^th months of treatment, was performed using SPSS version 23.0, with a significance level set at 0.05.

Results: MMP-2 activity was undetectable in the zymograms. In the 4^th month of treatment, MMP-9 activity was more prominent in the case group, though this disparity did not reach statistical significance in the 5^th month. Furthermore, MMP-9 activity did not exhibit a correlation with the GE score.

Conclusion: The activity of MMP-9 in the saliva of orthodontic patients with GE increases during the 4^th month of treatment, but no correlation exists with the degree of GE.

Background: The main disadvantage of silver diamine fluoride (SDF) is its persistent dark coloring. The aim of this study was to cover this discoloration on affected primary tooth dentin with different materials and subsequently measure their shear bond strength (SBS).

Materials and methods: In this in vitro study total of 60 primary teeth were demineralized and randomly divided into five groups (n = 12). The tooth surfaces were treated with 38% SDF, and restorative cylinders were built on the dentin as follows: (1) phosphoric acid etching + GLUMA Universal Adhesive (GUA; etch-and-rinse mode) + composite resin (CR); (2) GUA (self-etch mode) + CR; (3) resin-modified glass ionomer (RMGI; Fuji II); (4) Surefil One (self-adhesive CR); and (5) TheraCem (self-adhesive resin cement) + CR. After restoration, the specimens were tested for SBS. Failure mode was determined by digital analysis and scanning electron microscopy. Data were analyzed by one-way analysis of variance and Tukey's honest significant difference post hoc test. P <0.05 indicated statistical significance.

Results: Group 1 had significantly higher mean SBS (P < 0.05) compared to Groups 2-5, while Group 5 had the least SBS (P < 0.001). Mean SBS differences between Groups 2 and 3 were not significant (P = 0.328). Group 4 had lower mean SBS than Groups 1 (P < 0.001) and 2 (P = 0.17). Most groups showed adhesive failure.

Conclusion: CR associated with the universal adhesive in etch-and-rinse mode had much higher SBS than the other groups; therefore, we recommend it to cover the dark discoloration generated by SDF.

Background: Optimal dimensional stability is required for successful root canal treatment. A sealant called EndoSeal mineral trioxide aggregate (MTA) was recently introduced to the market due to its favorable physical and chemical properties. On the other hand, AH Plus (AHP) is considered the gold-standard seal.

Materials and methods: In this ex vivo quasi-experimental study, 24 single-canal premolars extracted from humans were cleaned and shaped with a motorized and rotary file, then that is divided into two groups. The teeth of each group were filled with gutta F3 and each type of sealant. The teeth were scanned by a micro-computed tomography device after 24 h. After 7 days of storage in phosphate-buffered saline solution, the samples were re-scanned. Data were analyzed using SPSS software (version 21). Descriptive data were presented as frequency, percentage, mean, and standard deviation. The Shapiro-Wilk and Kolmogorov-Smirnov tests were used to investigate the normality of the data. The Mann-Whitney test was used to compare the two groups, and the differences were ultimately not significant. The level of significance was set at 0.05 (P < 0.05).

Results: The mean differences between sealer volumes before and after the intervention were not significantly different between the two groups indicating that the EndoSeal MTA sealer is not inferior to the gold-standard root canal sealer, AHP.

Conclusion: EndoSeal MTA can be considered a reliable sealer in endodontic treatments and be subjected to further investigation.

Background: Various methods, including the use of probiotics, have been suggested to prevent caries. Caries, which is mainly caused by Streptococcus mutans, is one of the bacterial diseases that imposes a heavy cost on society. The present study was conducted to investigate the probiotic products available in Iranian pharmacies that are used for caries prevention.

Materials and methods: In this double-blind randomized clinical trial, 40 students of medicine and pharmacy were randomly allocated to two equal groups of intervention and control using random allocation software. The intervention group used a probiotic pill containing Streptococcus salivarius M18 and K12 bacteria every night before going to bed. The control group used a mouth freshener tablet with the same flavor as the probiotic tablet every night before going to bed. The data were analyzed by SPSS (version 24) software using descriptive statistics (central tendency and dispersion) and inferential statistics (paired t-test and independent t-test). Data were collected using Excel software, and statistical analyses were performed by SPSS software (version 24).

Results: The mean number of S. mutans in the intervention group was 754.5 cfu/mm before the intervention and 1701.5 cfu/mm after the intervention, which showed a statistically significant difference (P < 0.05). In the control group, the mean S. mutans was 683 cfu/mm at the beginning of the intervention and 659 cfu/mm at the end of the intervention, which did not indicate a statistically significant difference (P > 0.05). Moreover, the normality of data was checked by the Kolmogorov-Smirnov test.

Conclusion: The mean number of S. mutans bacteria in the group using probiotic tablets was significantly increased compared to those of the control group. However, further studies are suggested to evaluate these products.

Clinical decision-making and biomedical research heavily rely on imaging techniques to visualize tissue morphology. To examine tissues in detail, it is necessary to use special histochemical stains to enhance contrast. This meta-analysis aimed to assess the sensitivity and specificity of these stains in diagnosing oral pathologic specimens. We conducted a search in 8 databases, including EMBASE, PubMed, Web of Science, Scopus, ProQuest, Ovid, Cinahl, and Cochrane, up to June 2022. Of 87,393 studies, 41 articles were selected for inclusion in our study. The results revealed that the specificity and sensitivity of the special histochemical stains were 86% with confidence interval (CI) 95%: 80%-90% and 83% with CI 95%: 75%-89%, respectively. Among the stains evaluated, toluidine blue, Papanicolaou, silver stain, Giemsa, Gram, feulgen, and periodic acid-Schiff (PAS) were the most frequently used for the detection of malignancy, premalignant lesions, dysplasia, and candidiasis. The specificity and sensitivity of each stain were analyzed individually, considering the type of specimen. Toluidine blue was the most commonly utilized special histochemical stain, particularly effective, for detecting malignancy, with a specificity of 97% with CI 95%: 88%-99% and sensitivity of 76% with CI 95%: 56%-89%. In conclusion, special histochemical stains are effective in diagnosing oral lesions, exhibiting reasonable specificity and sensitivity, especially in cases of premalignant and malignant lesions. Based on the reviewed articles in our study, the silver stain was identified as highly sensitive, while Giemsa and Papanicolaou stain exhibited the highest specificity.

Background: In this study, the effects of pure AH Plus sealer and its combination with triple antibiotic paste at different concentrations on Enterococcus faecalis bacteria have been investigated.

Materials and methods: This in vitro study was accomplished by the means of a triple antibiotic paste combination (minocycline, metronidazole, and ciprofloxacin) at different concentrations (0%, 1%, 5%, 10%, and 25%) with AH Plus sealer on E. faecalis bacteria. Sealers were set in an incubator for 1 h, 1 day, 3 days, and 7 days, and then 10 µL of bacteria solution was placed on all samples except the negative control group. After drying for 1 h, 250 µL brain-heart infusion broth culture medium was added, and it was cultured in solid media. Direct contact test technique was performed, and the obtained data were analyzed by 1-way ANOVA, 2-way ANOVA, 3-way ANOVA, and post hoc test least significant difference. It should be noted that the data were evaluated at the significance level of P < 0.05.

Results: The average of colony-forming unit (CFU)/mL illustrated that there were no significant differences between fresh antibiotic-sealer combination, 1-day set, and 3-day set (P = 0.525), while in sealer with 7-day set, the average of CFU/mL was notably lower than other sets (P < 0.001). The outcomes revealed a considerable variation by passing time and the number of CFU/mL was remarkably reduced (P < 0.05). The data suggested that, by increasing the concentration, the average of CFU/mL was decreased, whereas the average of CFU/mL did not have significant differences in all concentrations of the antibiotic-sealer combination compared to pure sealer (P < 0.05).

Conclusion: The concentration of 1% triple antibiotic in combination with root canal sealer may become a crucial factor for inhibiting the growth of remaining bacteria.

Background: The study aims to assess the clinical efficacy of periosteal pedicle graft (PPG) as a barrier membrane in guided tissue regeneration (GTR) for gingival recession, intrabony, and furcation defects.

Materials and methods: Electronic and hand searches were performed to identify randomized controlled/clinical trials investigating GTR using PPG, with 6-month follow-up. Primary outcomes recorded: probing depth (PD), clinical attachment level (CAL), bone fill, recession depth (RD) reduction, percentage of mean root coverage, keratinized tissue width (KTW), and bone defect area (BDA).

Results: Thirteen articles were selected; 6 for recession, 2 for furcation, and 5 for intrabony. Meta-analysis was performed whenever possible, results expressed as pooled standardized mean differences (SMDs). In recession defects, the RD pooled SMD is 0.47 (95% confidence interval (CI) = [-0.50-1.44]), KTW pooled SMD is 1.30 (95% CI = [-0.30-2.91]), favoring PPG over the comparator. In furcation defects, PD pooled SMD is 1.12 (95% CI = [-2.77-0.52]), CAL pooled SMD is 0.71 (95% CI = [-1.09-2.50]), and bone fill pooled SMD is 0.67 (95% CI = [-3.34-4.69]) favoring PPG. In intrabony defects, PD pooled SMD is 0.54 (95% CI = [-2.12-1.04]), CAL pooled SMD is 0.23 (95% CI = [-1.13-0.68]), and BDA pooled SMD is 0.37 (95% CI = [-1.58-2.31]) favoring PPG. The results were not statistically significant.

Conclusion: The current evidence indicates that PPG constitutes a valid and reliable alternative to collagen barrier membranes for successful GTR.

Background: Clinical trials investigating the efficacy of oral health prevention materials have conventionally used indices to evaluate the amount of plaque on tooth surfaces. Various methods, including the use of probiotics, have been suggested to prevent oral disease. The present study was conducted to investigate the probiotic products available in Iranian pharmacies that are used for the prevention of dental disease.

Materials and methods: In this double-blind randomized clinical trial, 40 students of medicine and pharmacy were randomly allocated into two equal groups of intervention and control using random allocation software. The intervention group used a probiotic pill containing Streptococcus salivarius M18 and K12 bacteria every night before going to bed. The control group used a mouth freshener tablet with the same flavor as the probiotic tablet every night before going to bed. The mean number of Streptococcus mutans bacteria in both the groups was calculated before and after using probiotic pills. The data were staticali analyzed by descriptive statistics (central tendency and dispersion) and inferential statistics (paired t-test and independent t-test) and Kolmogorov-Smironove tests (P<0.05).

Results: The plaque index values at the beginning of the study showed no statistical differences between the intervention and control groups (P = 0.85). The plaque index values in the intervention group before and after the intervention were 0.41 and 0.75, respectively, which showed a statistically significant difference (P < 0.05). The plaque index values in the control group before and after the intervention were 0.42 and 0.42, respectively, which indicated no statistically significant difference (P > 0.05).

Conclusion: The mean plaque index in the group using probiotic tablets was significantly increased compared to those of the control group. However, further studies are suggested to evaluate these products.

Background: To provide a continuous seal of the root canal, root-filling material should bond to the root canal dentin, ensuring the integrity of both the root-filling material and dentin remains in a static and functional state. The present study assessed the push-out bond strength of mineral trioxide aggregate (MTA) and cold ceramic (CC).

Materials and methods: In this laboratory trial study, 20 single-rooted, extracted human teeth without caries and cracks were selected. Each tooth was mounted in cold-curing resin. Then, 3 mm slices of mid-root dentin were obtained from each tooth. The specimens were randomly divided into two groups (n = 10) and filled with MTA ProRoot and CC. All specimens were stored for 30 days in an incubator at 37°C and 100% humidity. The push-out bond strength of the test materials was measured using a cylindrical punch with a 1-mm diameter. The punch was pushed against the test specimen at a speed of 1.0 mm/min using a universal material testing machine, extruding the filling test material. The push-out force during the test was recorded, and then, the internal surface of the teeth was examined to evaluate the mode of failure. Independent t-test and Chi-square were used to analyze the data. P < 0.05 was considered a significance threshold.

Results: The mean push-out bond strength in the CC group was 24.58 (MPa), and in MTA ProRoot, it was 23.77. No significant difference was observed between the two groups. The most frequent mode of failure in both groups was adhesive failure.

Conclusion: The two materials have adequate push-out bond strength to root dentin, and there is no difference between the bond strength and mode of failure of the two materials.