Amir Reza Rokn, DDS, MSc
Mohammad-Sadegh Ahmad-Akhoundi, DDS, MSc.
Shahroo Etemad-Moghadam, DDS, MSc.
Abbas Mirzaei, PhD
Vol 15, No 5 (2018)
Objectives: Irrigation plays a critical role in endodontic treatment. Various single and combined irrigants and irrigation protocols are available. The aim of this study was to evaluate the effect of some common irrigation protocols on the coronal fracture resistance of endodontically treated teeth undergoing bleaching.
Materials and Methods: After preparation of access cavities in 120 maxillary premolars, the teeth were divided into five groups (n=24) based on the irrigation protocol; G1:2.5% sodium hypochlorite (NaOCl), G2: 2% chlorhexidine (CHX), G3: NaOCl+CHX, G4: NaOCl+ethylenediaminetetraacetic acid (EDTA), G5: NaOCl+EDTA+CHX. Each group was subdivided into 2 subgroups of A: non-bleached (NB) and B: bleached (B). In subgroup B, the teeth underwent in-office and at-home bleaching techniques using 38% hydrogen peroxide and 20% carbamide peroxide gels for 3 weeks. The teeth were restored with composite resin, thermocycled, incubated for 24 hours, and underwent fracture resistance tests. Data were analyzed with one-way analysis of variance (ANOVA) and t-test (α=0.05).
Results: T-test showed significant differences between every two corresponding groups (P<0.0001). In subgroup A, the minimum fracture resistance was recorded in G1. Also, G2 specimens exhibited a significantly higher fracture resistance compared to G1, G4, and G5. In subgroup B, G2 specimens exhibited a significantly higher fracture resistance compared to G1 and G4 that were irrigated using NaOCl and NaOCl+EDTA.
Conclusions: It can be concluded that irrigation protocols can affect the coronal fracture resistance of bleached endodontically treated teeth, and specific irrigation protocols can be recommended for teeth undergoing bleaching.
Objectives: This study sought to assess the relationship of oral health literacy (OHL)of the parents with DMFT index ofthemselves and their children.
Materials and Methods: This cross-sectional study was performed on 258 children presenting to the Pediatric Dentistry and Orthodontics Departments of XXX in 2016 along with their parents. The parents were asked to fill out the OHL questionnaire, the validity and reliability of which had been previously confirmed in the Iranian and non-Iranian populations. Also, both parents and children were clinically examined to determine their DMFT index according to the WHOcriteria. Backward linear regression model was applied to assess the effect of demographic factors on OHL, behavioral habits and DMFT. The Pearson’s bivariate correlation was used to assess the relationship of OHL, behavioral habits and health indices.
Results: A significant linear correlation was noted between OHL of the parents with (f) in children. Only 48.5% of parents had adequate OHL. Children whose parents had adequate OHL had a significantly higher (f) and lower (m). Children whose parents had inadequate or marginal OHL had significantly lower (f) and higher (m).
Conclusion: Higher OHL of the parents significantly improves the DMFT index of themselves and their children and enhances their oral health behavior. Thus, programs must be implemented in developing countries like Iran to promote the OHL of the parents and consequently improve the oral health status of children.
Objectives: The aim of this study was to evaluate the diagnostic accuracy of different filtrations and slice thicknesses of cone-beam computed tomography (CBCT) in the detection of occlusal caries.
Materials and Methods: One-hundred teeth were selected for this ex-vivo experimental study. The CBCT images of the teeth were evaluated and scored by two observers in panoramic and cross-sectional views using different slice thicknesses and filtrations. Paired t-test, repeated-measures analysis of variance (ANOVA), and the least significant difference (LSD) test were used to compare the data with the histological gold standard. Receiver operating characteristic (ROC) analysis was used to determine the diagnostic accuracy of each slice thickness and filtration (P<0.05).
Results: The mean score of true caries detection in cross-sectional views was lower than that in panoramic views (P<0.05). Repeated-measures ANOVA showed a significant difference in the mean of true detections in different thicknesses of cross-sectional views, but this difference was significant only between 5 mm thickness and other thicknesses in panoramic views. On all the views, increasing the thickness decreased the accuracy of caries detection. Repeated-measures ANOVA showed a significant difference between different filtrations; on all the views, increasing the filtration increased the accuracy of caries detection.
Conclusions: An increase of filtration of CBCT images increases the accuracy of occlusal caries detection; however, an increase in slice thickness results in a lower diagnostic accuracy.
Objectives: The aim of this study was to assess the antibacterial activities of OrthoMTA, RetroMTA, and ProRoot MTA against Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), and Prevotella intermedia (Pi).
Materials and Methods: Each material was mixed on a glass slab using a spatula and was placed in columns containing the filter membrane of the modified membrane-enclosed immersion test (MEIT) system. The materials were sterilized after setting. The columns containing the sterilized test materials were placed in microcentrifuge tubes containing 500 µl of bacterial suspension. The systems were then incubated at 37°C under anaerobic conditions. After 72 hours, the bacterial growth and concentration (colony-forming unit (CFU)/ml) were assessed. The results were analyzed using one-way analysis of variance (ANOVA) and Tukey's post-hoc test in SPSS 22 software. In all analyses, the differences were considered significant at P<0.05.
Results: OrthoMTA had the highest antibacterial activity against Pi. The mean number of CFU/ml of Fn in the presence of ProRoot MTA and RetroMTA was significantly lower than that in positive controls. There were significant differences between the antibacterial activities of ProRoot MTA and OrthoMTA against Pg compared to positive controls.
Conclusions: ProRoot MTA, OrthoMTA, and RetroMTA had similar antibacterial activities against the three evaluated anaerobic endodontic bacteria, except RetroMTA against Pg.
Objectives: This in-vitro study aimed to compare the push-out bond strength of composite resin posts packed into the root canal of primary anterior teeth using two different layering techniques.
Materials and Methods: Thirty-two primary anterior teeth were randomly divided into two groups. In group 1, after the preparation of post spaces, a posterior composite resin (Filtek P60) was packed in three horizontal layers by a composite condenser instrument with a cylindrical tip using the horizontal layering technique (HLT). In group 2, this was done using a condenser with a conical tip in three funnel-shaped layers according to the funnel-shaped layering technique (FSLT). Next, the specimens were subjected to push-out bond strength testing. Data were analyzed using t-test and the Kaplan-Meier curves.
Results: The mean±standard deviation (SD) bond strengths of composite resin posts were 8.46±3.45 MPa and 7.7±2.24 MPa for the HLT and FSLT, respectively; the difference was not statistically significant (P=0.46).
Conclusions: The layering technique by which composite resin was packed into the root canal of primary anterior teeth (HLT versus FSLT) had no significant effect on the push-out bond strength of composite resin posts.
Objectives: Considering the optimal efficacy of bromelain for pain relief and wound healing, this study aimed to assess the effect of bromelain on wound healing, pain, and bleeding at the donor site following free gingival grafting (FGG).
Materials and Methods: This randomized, controlled double-blind clinical trial was performed on 26 patients with gingival recession. The patients were randomly divided into two groups of bromelain and placebo (n=13). Treatment was started on the day of surgery and was continued for 10 days. Pain, bleeding, and epithelialization at the donor site were the variables evaluated in this study using a questionnaire. The level of pain was determined using a visual analog scale (VAS) considering the number of analgesic tablets taken within 7 days postoperatively. Bleeding was determined according to the patient’s report, and epithelization was assessed by applying 3% hydrogen peroxide (H2O2) to the donor site. The donor site epithelialization was assessed at 7 and 10 days after surgery.
Results: Bromelain caused a significant reduction in pain at the donor site (2.605±0.509) compared to the placebo (4.885±0.519; P<0.05). The number of donor sites with complete epithelialization was higher in the bromelain group compared to the placebo, but this difference was not statistically significant (P>0.05). The two groups were the same regarding postoperative bleeding (P>0.05).
Conclusions: The results showed that oral bromelain (500 mg/day) can be effective in the reduction of pain at the donor site after FGG and may also enhance wound healing. Oral bromelain does not increase the risk of postoperative bleeding.
Objectives: This study aimed to evaluate the effect of oral melatonin and oral midazolam as premedication for intravenous (IV) sedation of pediatric dental patients.
Materials and Methods: This crossover, double-blind randomized clinical trial was conducted on 23 uncooperative 2-6-year-olds with definitely negative behaviors according to the Frankl's scale. Each child served as their own control. The children were randomly divided into two groups: group I received 0.5mg/kg of oral melatonin one hour before IV sedation, while group II received 0.5mg/kg of oral midazolam 30 minutes before IV sedation on their first visit. Every child received the other premedication on their second visit. The degree of sedation was judged according to the Houpt scale. Physiologic parameters including blood pressure (PB), heart rate (HR), and blood oxygen saturation (SpO2) and side effects including dizziness, nausea, vomiting, and sleepiness were assessed. The parents' and the operator's satisfaction rates were scored. Data were analyzed using paired t-test and Wilcoxon signed-rank test.
Results: There were significant differences in sedation scores between the two sessions (P<0.05). However, there were no significant differences in alterations of physiologic parameters between the two sessions (P>0.05). Nausea and vomiting were more common during the first two hours in the midazolam group (P=0.002). Tremors were more common in the melatonin group (P=0.013). Dizziness was more evident when melatonin was used (P<0.001). The clinician and the parents were more satisfied with the results of midazolam intake (P<0.05).
Conclusions: Premedication with oral midazolam in pediatric patients is superior to that with melatonin with a higher parents' and operator's satisfaction.
Objectives: Pressure transmission under denture bases can vary depending on the denture tooth material. The aim of the present study was to evaluate pressure transmission under denture bases using denture teeth of different materials in direct and indirect tooth contacts.
Materials and Methods: In this in-vitro study, the pressure transmission generated by five types of denture teeth, including ceramic, nanocomposite, composite-acrylic resin, cross-linked acrylic resin, and polymethyl methacrylate (PMMA), under direct and indirect pressures was evaluated (n=10). The maximum pressure (MPa) was measured using a strain gauge. Data were statistically analyzed with one-way analysis of variance (ANOVA; α=0.05).
Results: The denture tooth material had a significant effect on pressure transmission under denture bases (P<0.001). Under direct load, ceramic and PMMA teeth exhibited the maximum and minimum pressures, respectively, contrary to indirect load (P<0.001).
Conclusions: Pressure transmission under denture bases significantly varies with the use of different denture tooth materials. Acrylic teeth could be the most favorable choice to reduce the pressure beneath denture bases. Nanocomposite and acrylic resin-composite teeth may be used as alternatives.
Amir Reza Rokn, DDS, MSc
Mohammad-Sadegh Ahmad-Akhoundi, DDS, MSc.
Shahroo Etemad-Moghadam, DDS, MSc.
Abbas Mirzaei, PhD
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