Permanent Molar Teeth Research Articles

Comparison of curative effect between different retrograde filling materials in young permanent molar root canal therapy.

The first mandible and maxilla permanent molars are the first permanent teeth that grow next to the deciduous teeth and may decay due to carelessness. Their caries can spread to the pulpal tentacles and cause pulpal and periapical diseases. In the current study, we tried to compare the curative effect of different retrograde filling materials, i.e. white MTA, gray MTA, Portland cement, and IRM, in young permanent molar root canal therapy. Because IL-1β stimulates bone degradation by osteoclasts, IL-1β gene expression was also measured for further evaluation. For this purpose, 400 students (240 boys and 160 girls) aged 8 to 11 years referred to the Pediatric Dental Center for first permanent molar root canal therapy were selected during two years. After recording the demographic characteristics of each patient, the first permanent molar teeth were examined by a general dentist with Abslang and decayed teeth were considered to have both discolorations in their grooves and apparent opacity. The patients, who need root canal therapy, were divided into four groups. The first group was treated with gray MTA. The second group was treated with white MTA. The third group received Portland cement for root canal therapy. The fourth group was treated with IRM. Also, IL-1β gene expression was evaluated by the real-time PCR technique. Relative changes in gene expression in PBMC cells were performed using One Way ANOVA. SPSS 18 software was used to determine the correlation of gene expression in PBMCs. The results showed that there was no significant difference between the groups in terms of age (p = 0.12) and gender (p = 0.24). Also, the need for endodontic treatment in the mandible (n = 278) was higher than the maxilla (n = 85) and both jaws (n = 37). But there was no significant difference between the groups in terms of the need for endodontic treatment (p = 0.32). The results of Pearson correlation coefficients between studied groups in terms of IL-1β gene expression showed that gray MTA and white MTA were not statistically different, but MTAs were generally different from Portland cement and IRM, with higher IL-1β gene expression. In general, the results showed that the teeth in the vicinity of gray MTA and white MTA showed a more appropriate response than Portland cement and IRM, so the use of MTA and its preference over other materials is recommended. In the case of Portland cement, more studies are needed to reach a conclusion comparing this material with MTA.

Evaluation of Gross Alpha and Beta Radioactivity Concentrations in Tooth Samples

Objective: Teeth are used as an important data source to estimate radioactivity accumulation in individuals. This study aimed to evaluation the gross alpha (GA) and gross beta (GB) radioactivity concentrations in tooth samples.Methods: Mandibular permanent first molar teeth of individuals living in the Middle Black Sea region were used for the study to ensure standardization. The teeth samples were divided into 4 groups according to the age factor (Group 1: 6-15 years, Group 2: 16-30 years, Group 3: 31-45 years, and Group 4: 46-65 years). Each group was divided into two subgroups according to gender factor. Measurements were completed with a nuclear spectroscopic system containing a gas-flow proportional counter. Data were analyzed statistically.Results: While a statistically significant difference was detected among groups for GA radioactivity concentration (p<0.05), no significant difference was detected among groups for GB (p>0.05). Mean GA value was higher in Group 1 (6-15 years) compared to the other groups. There was no statistically significant difference between the genders in both GA and GB radioactivity concentrations for all groups (p>0.05).Conclusion: While the GA radioactivity concentration was affected by the age factor, it was not affected by the gender factor.

A Scanning Electron Microscope Evaluation of the Efficacy of Different Fluoride-releasing Dental Restorative Materials to Prevent Enamel Demineralization: An In Vitro Study

Aim of the present research was to investigate the effectiveness of various fluoride-releasing dental restorative agents in preventing demineralization of enamel. Eighty human mandibular permanent molar teeth constituted the study group. All samples were subjected to storage in thymol, after which they were taken out to prepare alike proximal box in each. Inductions of artificial enamel surface lesions were done by placing the teeth in demineralizing solution for 96 hours. Subsequently, all 80 molars were randomly assigned to any of the four groups (i.e., 20 in every individual group) according to the restoration as group A: giomer (composite resin containing surface pre-reacted glass-ionomer fillers), group B: compomer (polyacid-modified composite resin), group C: resin-modified glass-ionomer cement (RMGIC), group D: fluoride-releasing composite. After this, the pH cycling was performed, and the samples were subjected to examination beneath scanning electron microscope (SEM). Higher mean areas of remineralization were noted when RMGIC (96.34 ± 0.06) was used followed by the compomer (109.52 ± 0.17), giomer (118.39 ± 0.82), and the fluoride-releasing composite group (129.27 ± 0.31) in that order. A statistically significant difference was seen amid the investigational groups that utilized different restorative agents (p <0.001). A pairwise evaluation that was performed revealed that except for the giomer group and the compomer group, a statistically significant difference (p <0.001) was found among the experimental groups. This research infers that the RMGIC-treated samples exhibited significantly superior performance in preventing enamel demineralization in comparison to compomer, giomer as well as fluoride-releasing composites. One among the highly frequently employed anticariogenic materials is fluorides. Owing to this characteristic, they are integrated into numerous restorative substances. Nevertheless, the quantity and speed of fluoride release differ in different agents, which translates to the efficacy of the restorative agent in avoiding demineralization about the restoration.

Apexification of an Immature Permanent First Molar Tooth with Cold Ceramic: A Case Report

Introduction: Apexification is a method to create a calcification barrier in teeth with open apex and pulp necrosis. For many years, calcium hydroxide was the most common substance for this purpose. Nowadays, apexification with other materials that can yield better results in one session has become more popular.&#x0D; Case report: For a 9-year-old boy complained of “tooth decay”, apexification treatment was performed by MTA on the lower right sixth permanent molar and by cold ceramic on the lower left sixth permanent molar. At one-year follow-up, no symptoms were observed on clinical examination and radiography of both teeth.&#x0D; Conclusion: Cold ceramic such as MTA can be considered effective in the apexification of immature tooth with pulp necrosis.

Etiology, Clinical Presentation, and Outcome of Mandibular Fractures in Immature Dogs Treated with non-Invasive or Minimally Invasive Techniques.

This study was performed to report etiology, clinical presentation, and outcome of mandibular fractures in immature dogs treated with non-invasive or minimally invasive techniques. Immature dogs diagnosed with mandibular fractures from 2001 to 2016 were included in this study. Diagnosis of the mandibular fracture was achieved by oral examination and diagnostic imaging in the anesthetized dog. Twenty-nine immature dogs with 54 mandibular fractures were selected. Within the mandibular body, the regions of the developing permanent canine and first molar teeth were most commonly involved (46.4% and 35.0%, respectively). Within the mandibular ramus, 53.8% of the fractures were located in its ventral half, and 38.5% in the condylar process. Muzzling was applied in 72.4% of the dogs. All dogs had clinical healing with resolution of signs of pain and recovery of mandibular function. Mean time for clinical healing was 21 ± 9 days. Age of the dog and duration of muzzling were significantly associated with the time needed for clinical healing. In immature dogs, fractures of the mandibular body occur most commonly in the regions of the developing permanent canine and first molar teeth, while fractures of the mandibular ramus are most commonly found in its ventral half and the condylar process. Non-invasive or minimally invasive management of mandibular fractures in immature dogs carries a good prognosis regarding clinical healing and recovery of mandibular function. Dogs should be monitored for the development of dental abnormalities and/or skeletal malocclusion until permanent teeth have erupted and jaw growth is completed.

A comparative evaluation of gingival microleakage and internal voids in Class II composite restoration with two different lining techniques: An in vitro study.

The aim of this study was to evaluate the gingival microleakage and internal voids in Class II composite restoration restored with precure and co-cure lining techniques using stereomicroscopic method. Forty-five freshly extracted permanent multirooted human molar teeth were collected and used in the study. After surface debridement and scaling of all teeth, standard Class II mesio-occlusal cavities were prepared. Forty-five samples were randomly divided into three experimental groups (n = 15), and filled according to manufacturer's instructions. Group I was precure group, Group II was co-cure group, and Group III was only bulk fill. The finishing and polishing of the restorations was done after 24 h. Then, all the specimens were subjected to thermocycling for 500 cycles. The gingival microleakage and internal voids of all the groups were evaluated using dye penetration method. Samples were then sectioned and examined under the stereomicroscope at ×40. Readings obtained were subjected to statistical analysis using SPSS ver 20.0 (IBM Corp, ARMONK USA) and Chi-square test. The statistical analysis revealed that extent of microleakage was maximum in Group II (co-cure), followed by Group III (only bulk fill) and Group I (precure). The gingival voids were maximum in Group III (only bulk fill), minimum in Group II (co-cure), and least in Group I (precure). The cervical voids were maximum in Group II (co-cure) and Group III (only bulk fill), followed by Group I (precure). The occlusal voids were maximum in Group II (co-cure) and similar in Group I (precure) and Group III (only bulk fill). The precure lining technique was better than co-cure lining technique in terms of both microleakage and internal voids.

Knowledge, Attitude and Clinical Practice of Dentists about Extraction of First Permanent Molars

The extraction of permanent first molar (PFM) teeth with poor prognosis allows the build of a new-and-ideal occlusion with the spontaneous movement of the healthy second and third molars by taking advantage of the patient's development. This study aimed to evaluate dentists' knowledge level about controlled tooth extractions and determine their information needs. The survey, consisting of 9 questions about balance and compensation extractions, was prepared on Google Forms and sent via email to dentists. The questionnaire was sent to 3137 dentists and 472 (15.04%) of them answered. While deciding on PFM extraction, the rate of those who checked the presence of permanent 3rd molar tooth was found to be 64.4%. Although 79% of pedodontists stated that they knew about balance extractions, only 60.9% of them apply it in the clinic. After maxillary PFM extraction, the rate of oral and maxillofacial surgeons who think that "mandibular PFM over-erupt" was 92.8%, and the rate of orthodontists was 68.7%. 87.1% of the participants stated that they needed more information about controlled extractions. It is possible to raise awareness, encourage the common and follow-up of correct clinical practices, and avoid complications; by adding controlled extractions to the undergraduate education program.

Daimi Birinci Molar Dişlerdeki Ektopik Erüpsiyon Özelliklerini Belirlemek İçin İki Farklı Sınıflandırma Sisteminin Kullanılması: Retrospektif Kesitsel Çalışma

Objective: The aim of this study is to determine the incidence of ectopic eruption in permanent first molar teeth retrospectively with 2 different classification methods, based on radiographic findings, during the transition from primary dentition to permanent dentition. Material and Methods: This study was conducted with children aged between 6-12 years admitted to pediatric dentistry department. The orthopantomographic radiographs of 2,516 patients were examined. The patients' age and gender, teeth with ectopic eruption and the jaw were recorded. In the classification of ectopic eruption, Young and Barberia-Leache et al.'s classification was used. Data were analyzed with IBM SPSS V23. Differences between teeth were examined with Cochran's Q test. The correlation between Barberia- Leache classification and Young's classification was evaluated with the chi-square test. Significance level was taken as p<0.05. Results: A total of 2,516 patients were included in the study and ectopic eruption was seen in a total of 70 teeth in 47 (23 girls, 24 boys) patients. The prevalence of ectopic eruption was found to be 1.9%. Ectopic eruption of the permanent first molar tooth was seen more in the upper jaw than in the lower jaw. According to Young's classification, the prevalence of permanent first molar eruption in reversible type is higher, while the prevalence of Grade I permanent first molar ectopic eruption is higher according to Barberia-Leache et al.'s classification. Conclusion: Even in cases of ectopic eruption in permanent first molars that are considered severe according to Barberia-Leache et al. classification and Young's classification, spontaneous recovery can be observed with long-term follow-up.

English

BACKGROUND Cavity disinfectants are frequently used for the elimination of bacteria that remain in the cavity, which are shown as the cause of secondary caries. However, its effect on microleakage from the tooth-restoration interface is still under investigation. The purpose of this study was to compare and evaluate the effects of the use of three different cavity disinfectants on microleakage in Class V composite restorations. METHODS For this study, 28 permanent third molar teeth without caries and restoration were used. Class V cavities of 4 mm x 3 mm x 3 mm were prepared on the buccal surfaces of each tooth. The teeth were randomly divided into 4 groups, with 7 teeth in each group. No cavity disinfectant was applied to the teeth in group 1. Tubulicid Red Label (Dental Therapeutics AB, Sweden) cavity disinfectant was applied to the 2nd group teeth, Cavity Cleanser (BISCO Inc., USA) cavity disinfectant to the 3rd group teeth, and Oxygenated Water (Dermosept, Turkey) cavity disinfectant to the 4th group teeth. Composite resin with universal adhesive and nanohybrid filler was applied to all samples in the groups in accordance with the recommendations of the manufacturers, and finishing and polishing processes were performed. Then, the thermal cycle (NOVA, Konya, Turkey) procedure was applied. After the restorations were covered with nail polish, they were kept in a 5 % basic fuchsin solution. The teeth were cut vertically in the buccolingual direction and examined with a stereomicroscope at x 40 magnification. The results were statistically evaluated with Kruskal-Wallis and Mann-Whitney U tests. RESULTS When the microleakage scores were compared between the control group and the groups treated with Tubulicid Red Label (p:0.204), Cavity Cleanser (p:0.204) and Oxygenated Water (P: 0.788), it was determined that there was no statistically significant difference (P &gt; 0.05). CONCLUSİONS It was determined that different cavity disinfectants applied in Class V cavities did not have a negative effect on microleakage and the closest results to the control group were seen in the group where cavity cleanser disinfectant containing 2 % chlorhexidine digluconate was applied. KEY WORDS Cavity Disinfectants, Class V Cavity, Microleakage.

Anti-caries evaluation of a nano-hydroxyapatite dental lotion for use after toothbrushing: An in situ study

ObjectivesThe aim of this randomized, double-blind, two-arm crossover in situ study was to investigate whether nano-hydroxyapatite (nanoHAP) dental lotion (Apagard Deep Care) applied immediately after tooth-brushing with nanoHAP toothpaste (Apagard M-plus) enhances the remineralization promotion and the demineralization inhibition efficacies of nanoHAP toothpastes. Methods64 sound enamel blocks and 64 blocks bearing artificially-produced initial caries were produced from human permanent molar teeth. During each treatment period, lasting 14 days per arm, two blocks, one sound and one lesion-bearing, were exposed to either 5% nanoHAP-containing or placebo dental lotion after tooth-brushing with 5% nanoHAP toothpaste, via an intra-oral appliance worn by 30 adults in each of the study groups. Baseline and post-test mineral loss were quantified using transverse microradiography (TMR). One-sided t-test of one group mean was used for intragroup comparison, while two-sided t-test of two independent means was used to compare the two dental lotions. ResultsPairwise comparison (baseline vs. post-test) indicated significant (p<.001) remineralization by nanoHAP toothpaste in both groups. However, when compared against each other, there was a significantly (p<.001) greater percentage of remineralization with nanoHAP lotion [58.4(±1.8)%] than with placebo lotion [37.7(±2.2)%]. TMR examination showed absolute demineralization inhibition in sound enamel blocks exposed to either lotions. ConclusionsToothpaste containing 5% nanoHAP effectively remineralized initial caries and inhibited demineralization of healthy enamel; however, the application of a dental lotion containing 5% nanoHAP after brushing resulted in superior remineralization compared to a placebo lotion. Clinical SignificanceDental lotion containing 5% nanohydroxyapatite used immediately after toothbrushing with 5% nanohydroxyapatite toothpaste can serve as an adjunct to enhance the clinical benefits of the toothpaste.

ICCMS™ root caries lesions stages and their underlying depth towards the pulp: an in vitro study with histologic evaluation.

To examine the relationship between the ICCMS™ (International Caries Classification and Managing System) features of root caries lesions and the underlying depth of the lesion towards the pulp. In order to control for bias, the study followed the tailored document for risk of bias assessment (RoB-tool) recently published. A pilot study showed that the outline of the pulp was much clearer on horizontal compared to vertical sections through the lesions (p = 0.03) and that the histological stereomicroscopical (SM) assessed lesion depth towards the pulp was not influenced by the cutting direction (p = 0.155). A sample of extracted permanent molar teeth (n = 100) were classifiedindependently by two of the authors according to ICCMS™ as no sign of root caries lesion 0 = sound; 1 = initial lesion (non-cavitated); 2 = moderate lesion (cavity depth ≤ 2mm) and 3 = extensive lesion (cavity depth > 2mm). After horizontal sectioning (HS) through the lesion, the depth of the underlying lesion was SM assessed independently by two of the authors as 0 = no lesion; 1 = lesion in outer 1/3; 2 = middle 1/3; and 3 = inner 1/3 of the dentine towards the pulp. Intra- and inter-reproducibility (weighted kappa values ≥ 0.83); the accuracy (Spearman's rho-values) = 0.94 and 0.95; and specificity/sensitivities/AUC values (three different thresholds) were ≥ 0.91, ≥ 0.93, and ≥ 0.96, respectively. Under the umbrella of the RoB-tool, the validity in terms of the reproducibility and accuracy of the ICCMS™ root caries scoring system was high. By means of the ICCMS™ root caries scoring system, the underlying lesion depth can be estimated, which must be considered when managing the lesion.

Sectional matrix system in reconstruction of proximal contact in class ii resin restoration

Background: Clinicians always faces some challenges to reconstruct proper proximal contact while restoring class-II cavity with composite resin due to its viscosity, elastic property and polymerization shrinkage. It has been claimed that use of sectional pre-contoured matrix band with separation ring will produce more reliable result for reconstruction of optimal proximal contact in class II composite resin restoration. Purpose: To evaluate the efficacy of sectional pre-contoured matrix band with separation ring for reconstruction of optimal proximal contact in class II resin composite restoration. Methodology: One Nissin manikin model having the facility of placing and screwing all upper and lower sets of artificial human teeth and sixty-two (62) artificial human mandibular permanent 1st molar teeth were collected. These 62 artificial human mandibular permanent 1st molars were randomly assigned in two groups (A &amp; B) having 31 teeth in each. Standardized class II MO (mesio-occlusal) cavity were prepared on total 31 artificial 1st molar in group A. The 2nd premolar in the manikin model was replaced by metal cast duplicate and permanently fixed into the socket. All the Thirty-one (31) 1st molar teeth in group A, having Prepared class II cavity in each, were replaced one by another in the manikin distal to cast duplicated 2nd premolar and restored with composite resin by using sectional pre-contoured matrix band with separation ring and another 31 uninstrumented intact artificial 1st molars were include in group B as a reference group. After completion of restoration, newly developed proximal contact points were measured by using universal testing machine one after another. Same were also done in intact reference Group B. Measurement was done to assess the position of contact point, contact tightness and contact area of Group A and Group B on the same typodont. The results were analyzed statistically with post hoc Bonferroni test (P&lt;0.05). Result: Teeth restored with sectional pre-contoured matrix with separation ring (group A) provided the tighter contact and broadened area of contact where all the contact points were placed more occlusally compared to that of the intact un-instrumented reference teeth (group B).Statistically significant differences (P&lt;0.05) were produced in all the three parameters with each other. Conclusion: Teeth restored with sectional pre-contoured matrix band with separation ring failed to reconstruct the optimal proximal contact in class-II composite resin restoration in comparison to intact uninstrumented reference tooth. Update Dent. Coll. j: 2021; 11(2): 16-19

Shear bond strength analysis and marginal gap evaluation of restoration–tooth interface of aesthetic restorations after simulated Co-60 gamma irradiation

Abstract Background: Radiotherapy to the head and neck region may cause considerable radiotherapy-induced changes in the surrounding tissues. These changes are oral mucositis, hyposalivation, dental caries, osteoradionecrosis, trismus and overall impact on patients’ quality of life. Tooth-coloured synthetic materials, unlike metallic restoration, did not influence radiation dose distribution. However, their exposure to a gamma radiation therapeutic dose during treatment might cause structural and compositional changes that alter their mechanical and physical properties. Aim: This study intends to evaluate the effect of Co 60 gamma rays on shear bond strength and marginal adaptation of already restored tooth surfaces, to help in material selection before the onset of radiotherapy. Materials and methods: Hundred freshly extracted human permanent mandibular molar teeth collected and stored in a 0·2% thymol solution for disinfection and were randomly divided into two groups of 50 each, to be tested for the shear bond strength of restoration to dentin and the marginal gap at tooth–restoration interface, respectively. Results: ANOVA showed a significant effect of both radiotherapy (F = 40·33, p &lt; 0·001) and restorations (134·00, p &lt; 0·001) on the marginal gap at the interface. In the without radiotherapy group, the mean marginal gap was least in Group Z250, and in with radiation, Bulk Fill has the least mean marginal gap. The mean shear bond strength was comparatively higher for all restorations without radiation than with radiation (p &lt; 0·001). Findings: Gamma radiation affects the physical or mechanical properties of tooth structure and the tooth restorative interface. Composites seem to be good restorative material when placed before the onset of radiotherapy in head and neck cancer patients.

Extra canal in permanent maxillary first molar in patients undergoing root canal treatment at a tertiary care dental hospital, Nepal

Background: Permanent maxillary first molar normally has three root canals but it can have extra root canals for which several studies were done in many parts of the globe. However, this type of study to explore extra canal is lagging in the context of Nepal. Objectives: The objective was to determine the percentage of extra canal in permanent maxillary first molar in patients undergoing root canal treatment and to compare the same between male and female. Methods: The descriptive cross-sectional study was conducted in the department of conservative dentistry and endodontics of People’s Dental College and Hospital from 20th December 2019 to 20th December 2020 after receiving ethical approval from Nepal Health Research Council on 18th December 2019 (ERB protocol No 888/2019) . One hundred and eighty permanent maxillary first molar teeth without root canal calcification were enrolled. Convenient sampling was done. Access opening was done and all canal orifices were located and recorded. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 22.0 with frequency table. Chi-square test was used for inferential statistics. Results: Out of 180 teeth, extra canals were present in 44(24.4%) having more numbers in male than in females. Extra canal was present in the mesiobuccal root. Conclusion: Extra canal in the permanent maxillary first molar is present in Nepalese population with greater number in male than in female. Thus, exploration of the pulp chamber in search of an extra canal is necessary to prevent failure of root canal treatment.

The evaluation of effectiveness of adhesive systems on dental amalgam restorations

Aim: The purpose of this study was to evaluate the effectiveness of different adhesive systems in amalgam restorations and their effects on microleakage.&#x0D; Methodology: In this study, 105 caries-free extracted human permanent molar teeth were used. Teeth were randomly assigned to five groups (n=21), and class I cavities were created on the surface of each tooth. The first was a control group to which no adhesive system was applied. Amalgam Liner (VOCO GmbH, Cuxhaven Germany) was applied to Group II, Clearfil SE-Bond (Kuraray Europe GmbH, Frankfurt Germany) was applied to Group III, Panavia F 2.0 (Kuraray Europe GmbH, Frankfurt Germany) was applied to Group IV, Amalgambond Plus (Parkell Inc.Edgewood, NY USA) was applied to Group V, and then amalgam (Tytin, Kerr, California USA) restorations were placed. After the polishing process, samples were subjected to thermocycling 1,000 times. Teeth were sectioned bucco-palatinally/lingually, and microleakage scores of the occlusal walls were evaluated under a stereomicroscope at 15X magnification by a standardized scale ranging from 0 to 4. One tooth was selected randomly from each group for SEM (Scanning Electron Microscope), and SEM LEO EVO 40 (LEO Ltd., Cambridge UK) photographs of amalgam-tooth hard tissue interfaces were also taken at different magnifications. The results of the microleakage tests were statistically analyzed by both the Kruskal-Wallis Test and the Mann Whitney U Test.&#x0D; Results: In terms of microleakage among groups, the differences that were determined were significant (p&lt;0.05). Microleakage within the control group was determined to be the highest, and statistically important differences were observed between the other groups. Group V (Amalgambond Plus) was determined to have the lowest microleakage scores.&#x0D; Conclusion: In prepared class I cavities, amalgam adhesive systems are effective in preventing occlusal microleakage but do not completely blocked it.&#x0D; &#x0D; How to cite this article: Ünal M, Atakul F. The evaluation of effectiveness of adhesive systems on dental amalgam restorations. Int Dent Res 2021;11(2):83-92. https://doi.org/10.5577/intdentres.2021.vol11.no2.5&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Three-Dimensional Tooth Models with Pulp Cavity Enhance Dental Anatomy Education.

Dental anatomy is an integrated, core fundamental dental course, which prepares students for all future clinical dental courses. This study aimed to build up an online dental learning platform of micro-computed tomography-based three-dimensional (3D) tooth models with pulp cavity, and to further evaluate its effectiveness for dental anatomy education using a cohort study. First, ninety-six extracted permanent teeth were scanned by micro-computed tomography and the enamel, dentine, and pulp cavity of each was distinguished by different grey-scale intensities using Mimics software. Three-dimensional images allowed further discrimination and insights into permanent three-rooted premolars, central tip, and dental diseases including deep caries and wedge-shaped defects. Furthermore, a second mesiobuccal canal (MB2) in maxillary permanent molar teeth and Vertucci type III root canal configuration in mandibular anterior teeth could be detected using the 3D analytical tool. A digitized 3D tooth model learning platform was implemented. Last, two groups of dental students were assessed to evaluate the effect of 3D models on dental anatomy education. Participants in the Digital group were allowed to use the online dental learning platform freely after class, while the participants in the Traditional group were not. Assessment quizzes showed that participants' scores improved in the Digital group with the use of the learning platform compared with scores in the Traditional group. A questionnaire survey indicated that the participants had a positive attitude toward the 3D models. Thus, adding digital 3D resources to a traditional curriculum may have a positive effect on academic achievements.

Influence of occlusal and proximal caries on the outcome of full pulpotomy in permanent mandibular molar teeth with partial irreversible pulpitis: A prospective study.

To assess the influence of occlusal and proximal deep carious lesions on the outcome of full pulpotomy performed in mandibular teeth with pulpal diagnosis of symptomatic partial irreversible pulpitis. Eighty deep carious mandibular molar teeth with clinical and radiographic diagnosis of symptomatic partial irreversible pulpitis without periapical rarefaction from patients of either gender between the age of 16-35years were included. Depending upon the location of deep carious lesion, the teeth were distributed equally into occlusal (n=40) and proximal caries groups (n=40). Full pulpotomy was performed under local anaesthesia and aseptic conditions. The pulp tissue was removed until the root canal orifices, and 2.5% sodium hypochlorite (NaOCl) was applied to arrest pulpal bleeding. Mineral trioxide aggregate (MTA) was compacted over the radicular pulp. Teeth were restored with resin-modified glass ionomer cement (RMGIC) and bulk-fill composite resin. Pre- and post-operative pain was assessed at 24, 48 and 72h using a 11-point Numerical Rating Scale (NRS). Patients were followed at 6 and 12months for clinical and radiographic evaluation. Asymptomatic teeth without any radiographic evidence of periapical rarefaction were considered successful. The data were analysed using the Shapiro-Wilk W test, two-sample Wilcoxon rank-sum test, Pearson chi-square test, Fisher's exact test and Kappa coefficient. The significance level was predetermined at p<.05. An intergroup comparison revealed that the pre- and post-operative pain scores at 24, 48 and 72h were not significantly different (p>.05). At the end of follow-up period (12months), success of full pulpotomy in occlusal and proximal caries group was 95% and 92.5%, respectively (p=.644). For both groups, the combined success rate of full pulpotomy was 93.75%. The site of carious lesions (i.e., occlusal or proximal) did not affect the clinical and radiographic outcome of full pulpotomy performed in mature permanent mandibular teeth with symptomatic partial irreversible pulpitis.

WITHDRAWN: Impact of riboflavin and curcumin mediated photodynamic therapy and Er,Cr:YSGG on microleakage of class V resin glass ionomer restorations in permanent molar teeth

The present study aimed to evaluate the impact of PDT using curcumin and riboflavin as photosensitizers and Er,Cr:YSGG on microleakage in class V RMGIC restorations in permanent teeth. Eighty permanent molars were investigated and randomly divided into 4 groups: control group: resin-modified glass ionomer restoration with no treatment, R-PDT: PDT with riboflavin, Cu-PDT: PDT with curcumin (Cu) and, Er,Cr:YSGG: laser application. All the teeth in each group were restored with the help of RMGIC. The samples were dipped for 24 h in 0.5 % Fuchsine solution, and subsequently fixed in acrylic resin-based molds. Microleakage scores were estimated considering both cervical and occlusal boundaries. Intergroup comparisons were made at each margin, and intragroup comparisons made at the cervical and occlusal margins. The Shapiro Wilk test was used to check the normality of the values. Whereas, the analysis of data was conducted using SPSS version 25 via the Kruskal-Wallis and Wilcoxon tests. P < 0.05 was contemplated to be statistically important. A high frequency (95%) of the enamel walls were not penetrated when subjected to treatment with R-PDT, followed by Cu-PDT and Er,Cr:YSGG. The highest amount of microleakage was observed (55%) Cu-PDT at the site of the cavity near the cementum. The least amount of microleakage was observed in the control group. A statistically significant difference in microleakage was noted at the cervical wall (p=0.015), while no significant difference was seen at the occlusal wall (p=0.789) between the groups. A significant difference was noted at the cervical wall between the control and R-PDT group (p=0.021) and Cu-PDT group (p=0.005), respectively. A significant difference in microleakage was observed when occlusal was compared with cervical walls within each group (p<0.05). Photosensitizers using riboflavin and curcumin may reduce the microleakage within the enamel surface restored with RMGIC in class V lesions that may not interfere with bonding. However, extreme caution should be taken while considering riboflavin and curcumin for class V RMGIC restorations extending to cementum surface.

Caries incidence of the first permanent molars according to the Caries Assessment Spectrum and Treatment (CAST) index and its determinants in children: a cohort study

BackgroundThere are limited information on caries incidence, especially from developing countries, the aim of the present study was to explore caries incidence in the first permanent molar teeth according to the CAST index in 7- to 8-year-old-children and its socio-demographic, oral health related and diet determinants.MethodsA multi-stage cluster random sample of 7–8 years old children was applied in Tehran, Iran. The oral examination using the CAST index and the Oral Hygiene Index-Simplified (OHI-S) performed by trained dentists in 2017 and 2019 calibrated with an expert (Kappa of 0.89 and 0.76, respectively). A 3-day food record was used to record sugary snacks consumption. Oral health related knowledge of the parents was assessed using a valid and reliable self-administered questionnaire. The data were analyzed using the SPSS software version 23.0 and descriptive and analytical statistics including the negative binomial regression was applied.ResultsTwo hundred and ninety schoolchildren aged 7–8 years old were followed up for two years. All of them had complete data obtained via oral examination and questionnaires. The annual caries incidence rate was 0.16 and 53% (95% CI 47.4–58.9) of the children developed at least one new dental caries (enamel or dentine) during two years. Multi-variate analysis revealed that the children of mothers with high school education or diploma (IRR = 1.47, 95% CI 1.02–2.12; p = 0.04) and those with low socio-economic status (IRR = 1.86, 95% CI 1.27–2.73; p < 0.001) were more likely to develop caries. There was no significant association between gender, father’s educational level, child birth order, housing area per person, OHI-S score, oral health knowledge of parents, and sugary snacks consumption per day and caries increment at an individual level.ConclusionThis 2-year longitudinal study on 7- to 8-year-old children showed that caries incidence according to the CAST index was associated with socio-economic status and mother education but not associated with having 2 or more sugary snack per day and oral hygiene status.

Microbiological and SEM assessment of atraumatic restorative treatment in adult dentition.

To investigate the practicability of atraumatic restorative treatment (ART) in adults in terms of marginal adaptation of restorations and microbiological changes in residual carious dentin. The occlusal dentin caries of 25 permanent molar teeth were removed with hand instruments. The total counts of bacteria (TCB) and the facultative anaerobic bacteria (FAB), mutans streptococci (MS), and Lactobacillusspp. (LB) counts in the affected dentin were evaluated quantitatively. The weights of the samples were measured with an electronic balance (Shimadzu, Type AX200, Japan). The cavities were restored with glass ionomer cement (KetacTM Molar Easymix, ESPE Dental AG, Seefeld, Germany). Twenty replicas of randomly selected ART restorations were prepared and marginal adaptation was evaluated by scanning electron microscopy (SEM). After 6 months, the same protocols were repeated. Data were analyzed with paired sample t-tests, Wilcoxon t-tests, Pearson and Spearman correlations, and chi-square tests (p<0.05). In the sixth month, restoration loss and pulpitis were not observed. The mean weight of samples removed from the cavity floor was less than the baseline (0.014±0.009 and 0.023±0.013 g, respectively) (p<0.01), and the counts of total bacteria, FAB, MS, and LB significantly decreased compared to baseline (p<0.01). The frequency of marginal gaps was increased (p< 0.01). ART showed that the counts of microorganisms decreased after 6 months although the marginal gap rates of restorations increased. ART can be a reliable treatment approach in adults for 6 months due to the decrease in microorganism counts, although gaps exist.