Stress distribution of endodontically treated mandibular molars with varying amounts of tooth structure restored with direct composite resin with or without cuspal coverage: A 3D finite element analysis.

Background: Decision-making regarding whether cuspal coverage is required or not for the restoration of root canal-treated posterior teeth is still a matter of challenge for the dentist. Methodology: Four models of endodontically treated mandibular molars with mesio-occlusal (MO) cavity were designed and simulated with direct composite resin restorations. Group 1A - cavity width <½ the intercuspal distance restored without cuspal coverage, Group 1B - same as Group 1A but with cuspal coverage, Group 2A - MO cavity width >½ but <2/3rd the intercuspal distance restored without cuspal coverage, and Group 2B - same as Group 2A but with cuspal coverage. The models received occlusal load to simulate a mastication load. Static finite element analysis (FEA) was adopted for predicting the stress distribution generated in the restored tooth by the loading condition. Results: FEA of the models have shown that the variations in stress values were significant in bulk-fill material compared to enamel and other structures. Comparing the maximum and minimum principal stress values in the overall region demonstrated that 2A was safer, whereas 2B was found to be the worst case. Conclusions: The results indicate that restoration of endodontically treated mandibular molar with loss of one marginal ridge with composite resin without cuspal coverage revealed minimal internal stress values and showed the best performance overall.

Incidence of Postoperative Pain after Single Visit Root Canal Treatment using XP-endo Shaper, 2Shape and ProTaper Gold Rotary Systems: A Prospective Randomized Clinical Trial.

OBJECTIVE: To evaluate the incidence of postoperative pain, treatment time and analgesic intake after single visit endodontic treatment of mandibular molars using XP-endo Shaper, 2Shape and ProTaper Gold rotary systems. METHODS: 150 patients with irreversible pulpitis were scheduled for single visit root canal treatment. Teeth were randomly assigned to one of the three groups: ProTaper Gold (PTG; Dentsply Tulsa Dental Specialties, Johnson City, TN), 2Shape (2S; Micro-Mega, Besancon, Cedex, France) and XP-endo Shaper (XPES; FKG Dentaire, La Chaux-de-Fonds, Switzerland). Preoperative and postoperative pain was rated by the patients at the beginning of treatment and after 24, 48, 72 hours and 7 days on Heft Parker's visual analog scale (HP-VAS). RESULTS: Highest mean postoperative pain score was recorded in PTG (P<0.05), followed by 2S and XPES respectively at all time intervals. XPES exhibited maximum reduction from preoperative pain at 24 (48.67%) and 48 hours (96.90 %) with no pain at 72 hours. Treatment time was significantly least in XPES (P<0.05) followed by 2S and PTG; but no significant difference in analgesic intake was noted. CONCLUSION: XPES exhibited least postoperative pain at all time intervals and treatment time, followed by 2S and PTG rotary systems respectively. (EEJ-2022-04-053).

Direct Pulp Capping with Mineral Trioxide Aggregate and Biodentine in Cariously Exposed Molar Teeth: 1-Year Follow-up - An In vivo Study.

Aim: To assess and compare the treatment outcome of direct pulp capping with mineral trioxide aggregate (MTA) and Biodentine, after complete excavation of caries in permanent dentition with a 2-visit treatment protocol. Materials and Methods: Direct pulp capping with white MTA was performed in 70 teeth. Direct pulp capping with Biodentine was also done in 72 teeth. In the subsequent visits after 2 weeks, pulp sensibility tests were attempted in both studied groups. All clinical outcomes were categorized as success or failure. Results: The success rate of the pulp capping procedure in the MTA group at the end of 12 months study was 94.3% in the Class I subgroup and 93.3% in the Class II subgroup. Conclusion: Direct pulp capping with MTA and Biodentine, after pulp exposure during excavation of deep caries could maintain pulp vitality in permanent teeth.

Does the presence and amount of epinephrine in 2% lidocaine affect its anesthetic efficacy in the management of symptomatic maxillary molars with irreversible pulpitis?

BACKGROUND: This was a randomized controlled clinical trial that aimed to evaluate the anesthetic efficacy of 2% lidocaine combined with different concentrations of epinephrine (plain, 1:200,000 and 1:80,000) during endodontic treatment of maxillary molars with symptomatic irreversible pulpitis. METHODS: The trial included 144 adult patients who were randomly allocated to three treatment groups. All patients received buccal-plus-palatal infiltration. After 10 min, pulp sensibility testing was performed using an electric pulp test (EPT). If a tooth responded positively, anesthesia was considered to have failed. In the case of a negative EPT response, endodontic access was initiated under rubber dam isolation. The success of anesthesia was defined as having a pain score less than 55 on the Heft Parker visual analog scale (HP VAS), which was categorized as 'no pain' or 'faint/weak/mild' pain on the HP VAS. Baseline pre-injection and post-injection maximum heart rates were recorded. The Pearson chi-square test was used to analyze the anesthetic success rates at 5% significance. RESULTS: Plain 2% lidocaine and 2% lidocaine with 1:200,000 epinephrine and 1:80,000 epinephrine had anesthetic success rates of 18.75%, 72.9%, and 82.3%, respectively. Statistical analysis indicated significant differences between the groups (P < 0.001, χ2 = 47.5, df = 2). The maximum heart rate increase was seen with 2% lidocaine solution with epinephrine. CONCLUSION: Adding epinephrine to 2% lidocaine significantly improves its anesthetic success rates during the root canal treatment of maxillary molars with symptomatic irreversible pulpitis.

A Comparative Evaluation of Smear Layer Removal Using Erbium:YAG Laser-Activated Irrigation, Sonic Irrigation, and Manual Dynamic Irrigation: A Scanning Electron Microscope Study.

Introduction: The conventional chemomechanical procedures are ineffective in complete disinfection of the pulp space due to the complexities of the root canal architecture. The present study aims to compare the efficacy of erbium: YAG laser-activated irrigation, sonic irrigation, and manual dynamic irrigation in the removal of the smear layer through a scanning electron microscope study. Methods: Fifty extracted single rooted mandibular premolars with single canal were used and instrumented until F3 ProTaper rotary file reached the working length. Upon the completion of the canal preparation, each specimen was irrigated with 3 mL of 4% NaOCl for 3 minutes, 3 mL saline for 1 minute and 3 mL of 17% EDTA for 3 minutes. The teeth were assigned to three experimental groups (n=15 each): manual dynamic irrigation, sonic irrigation (EndoActivator), and Er:YAG laser using an X pulse tip. Root canals were sectioned longitudinally and the smear layer at the apical, middle and coronal third was examined under a scanning electron microscope. Smear layer scores were analyzed by Kruskal-Wallis and Mann-Whitney U tests at P = 0.05. Results: The Er:YAG laser group showed significantly lower smear layer scores in the apical third as compared to all other groups. EndoActivator resulted in better cleaning efficacy at the apical area compared to manual dynamic agitation. Conclusion: This study showed results in favor of Er:YAG with an X-pulse tip followed by EndoActivator activation.

Clinical Efficacy of Resin Infiltration Technique Alone or in Combination with Micro Abrasion and in-Office Bleaching in Adults with Mild-to-Moderate Fluorosis Stains.

BACKGROUND: The present study was conducted to evaluate the clinical efficacy of resin infiltration technique alone or in combination with microabrasion and in-office bleaching in adults with mild-to-moderate fluorosis stains on permanent maxillary anterior teeth at the end of 1 month. MATERIALS AND METHODS: A total of 30 patients with nonpitted fluorosis stains on maxillary anterior were classified as mild (n = 15) and moderate (n = 15). Each grade is subdivided into three groups as Group A, Group B, and Group C. Group 1: Mild (score 2), Subgroup A: Resin infiltration (n = 5 patients), Subgroup B: Microabrasion followed by resin infiltration (n = 5 patients), Subgroup C: Microabrasion and bleaching followed by resin infiltration after 2 weeks (n = 5 patients). Group 2: Moderate (score 3), Subgroup A: Resin infiltration (n = 5 patients), Subgroup B: Microabrasion followed by resin infiltration (n = 5 patients), and Subgroup C: Microabrasion and bleaching followed by resin infiltration after 2 weeks (n = 5 patients). Microabrasion was performed with the opalustre kit from Ultradent according to the manufacturer's instructions. Pola office bleaching from SDI and Icon infiltrant was performed. Stain score, improvement in appearance score, need for further treatment, patient satisfaction score, tooth sensitivity immediately after treatment, 24 h and 72 h were recorded. RESULTS: The mean appearance score in Group 1A was 73.60, in Group 1B was 72.87, in Group 1C was 65.27, in Group 2A was 68.00, in Group 2Bwas 72.93 and in Group 2C was 84.73. The mean need for further treatment score in Group 1A was 72.80, in Group 1B was 78.40, in Group 1C was 68.73, in Group 2A was 71.20, in Group 2B was 79.53 and in Group 2C was 88.73. The mean patient satisfaction score in Group 1A was 91.40, in Group 1B was 95.20, in Group 1C was 98.00, in Group 2A was 90.20, in Group 2B was 99.40 and in Group 2C was 100.00. There was a significant difference in mean tooth sensitivity immediately after treatment between Groups 1A, 1B, 1C, 2A, 2B, and 2C. There was a significant difference in mean tooth sensitivity after 24 h between Groups 1A, 1B, 1C, 2A, 2B, and 2C. CONCLUSION: Resin infiltration technique in combination with bleaching and microabrasion technique found to be effective in the management of dental fluorosis.

Comparison of fracture resistance of endodontically treated maxillary first premolar with mesio-occlusal-distal access restored with composite resin, fiber post, and prefabricated metal posts restored with/without full-coverage metal crowns.

Background: A myriad of materials and procedures have been recommended for restoring the root-filled teeth with significant loss of tooth structure and the most common method being the use of "posts." Material and Methods: A mesio-occluso-distal preparation was done on eighty intact maxillary first premolars, followed by access preparation and cleaning and shaping with rotary files. All samples were obturated and divided into four groups (n = 20). In Group 1, 3-mm gutta-percha was removed and restored using composite resin; Group 2 - Group 1 + crowns; Group 3 - prefabricated fiber post + crowns; and Group 4 - prefabricated metal post + crowns. All the groups were subdivided into eight groups (n = 10), fractured with 90° vertical and 45° oblique loading by a universal testing machine. Statistical Analysis: Fracture resistance was analyzed and compared by means of two-factorial two-way analysis of variance and Scheffe's post hoc test. Results: Under 90° loading, the fracture load of teeth restored with the Nayyar's composite resin core and crown was greatest. Under 45° loading, the fracture load of teeth restored with prefabricated metallic posts was significantly (P < 0.05) less than that in other groups. Under 45° load, group with fiber post exhibited significantly (P < 0.05) more number of favorable fractures than other groups. Conclusion: Under the conditions of vertical and oblique loadings, fiber post and composite resin core with a full-coverage crown is the most effective restorative modality for protecting the remaining tooth structure in pulpless teeth.

An In Vitro Study of Effect of Beveling of Enamel on Microleakage and Shear Bond Strength of Adhesive Systems in Primary and Permanent Teeth.

AIM AND OBJECTIVES: This in vitro study evaluated the effect of beveling of enamel on microleakage and shear bond strength of total-etch adhesive system: prime and bond NT and self-etch: adhesive system: XENO V in primary and permanent teeth. MATERIALS AND METHODS: A total of 120 extracted human molars (60 primary and 60 permanent) were selected for the study. For microleakage examination, a sample size of 40 was chosen. Two rectangular slots of equal dimensions were prepared on the buccal surface of each tooth and a bevel was given on either of the slots. Each slot was restored using a composite resin with prior application of the selected bonding agent following which all the samples were soaked in 1% methylene blue dye for 48 hours. Then each tooth was sectioned horizontally and evaluated. The remaining 80 samples were subjected to the shear bond strength test. Class II cavities of standard dimension were prepared and bevel was given on each sample following which selected bonding agent was applied and restored with a composite resin. The specimens were placed in a fixture and the shear bond strength was determined using the universal testing machine. RESULTS: With respect to microleakage, the least was exhibited by beveled preparations in permanent teeth using the self-etch adhesive system and the highest shear bond strength was exhibited by beveled preparations using the total-etch adhesive system in permanent teeth. CONCLUSION: Beveling of enamel improved the marginal integrity and shear bond strength of self-etch and total-etch adhesive systems in both primary and permanent teeth. HOW TO CITE THIS ARTICLE: Patanjali S, Arora A, et al. An In Vitro Study of Effect of Beveling of Enamel on Microleakage and Shear Bond Strength of Adhesive Systems in Primary and Permanent Teeth. Int J Clin Pediatr Dent 2019;12(3):205-210.

Dental Pulp Status of Posterior Teeth in Patients with Oral and Oropharyngeal Cancer Treated with Radiotherapy: 1-year Follow-up.

INTRODUCTION: Teeth may react negatively to pulp sensitivity testing in patients who have undergone radiotherapy. The aim of the current investigation was to evaluate the pulp sensibility of posterior teeth at 4, 6, and 12 months in patients who have undergone radiotherapy for oral and oropharyngeal malignancies. METHODS: Seventy-nine patients diagnosed with malignant oral and oropharyngeal cancer undergoing radiotherapy underwent cold thermal pulp sensitivity testing and electric pulp testing of 4 teeth, 1 from each quadrant. The results were recorded at 5 different time points (TPs): before radiotherapy (TP1), at the end of radiotherapy at 66-70 Gy (TP2), 4 months after the completion of radiotherapy (TP3), 6 months after the completion of radiotherapy (TP4), and 12 months after the completion of radiotherapy (TP5). RESULTS: All 288 teeth tested positive to cold thermal pulp sensitivity testing and electric pulp testing (EPT) at TP1 (100%). No tooth responded to the cold test (100%) at TP4 and TP5, and progressively higher EPT values were noted during the observation period. A statistically significant difference existed in the number of positive responses between different TPs. CONCLUSIONS: There was a progressive decrease in pulp sensibility from TP1 to TP5 in teeth of patients with oral and oropharyngeal cancer who underwent radiotherapy (66-70 Gy). No response to cold thermal tests was noted at TP4 (6 months) and TP5 (12 months), and teeth responded at increasingly higher EPT values from TP1 through TP5. This result was statistically significant.

Cone-beam Computed Tomography Volumetric Analysis and Comparison of Dentin Structure Loss after Retrieval of Separated Instrument by Using Ultrasonic EMS and ProUltra Tips.

INTRODUCTION: A separated instrument within the root canal may interfere in the successful outcome of endodontic treatment. The retrieval of fractured instruments might compromise the remaining tooth structure and subsequently resistance to tooth fracture. The aim of this study was to compare the change in volume of root canal and dentin thickness after retrieval of separated instrument by 2 different endodontic ultrasonic tips. METHODS: Each of the instruments (EMS Endochuck and ProUltra #6, #7, and #8 tips) was used to remove 40 separated rotary ProTaper F2 instruments from the mesiobuccal roots of mandibular molar under ×15 magnification. Cone-beam computed tomography analysis of the samples was done to evaluate the change in volume, dentin thickness, weight, time taken, and success. RESULTS: Paired sample t test showed statistically significant (P < .05) difference in volume before and after instrument retrieval in both the EMS group, where the increase was 112.52%, and in the ProUltra group, where the increase was by 55.35%. Intergroup comparison showed statistically significant (P < .05) decrease in dentin thickness; it was more for EMS as compared with ProUltra. Overall decrease in the mean weight of EMS group (18.42%) was more than that of ProUltra group (9.36%). The overall success rate for removal of fractured instrument in this study was 87.5%; however, the difference in success rate was not statistically significant. The mean time taken for retrieval by ProUltra system was 63.89 minutes, whereas it was significantly less (P < .05) for EMS system (50.22 minutes). CONCLUSIONS: Removal of separated instrument with EMS resulted in more significant tooth structure loss as compared to ProUltra.

Dental Pulp Status of Posterior Teeth in Patients with Oral and Oropharyngeal Cancer Treated with Concurrent Chemoradiotherapy.

INTRODUCTION: The absence of tooth sensitivity has been observed in patients who have undergone radiotherapy. The aim of this investigation was to evaluate the effects of concurrent chemoradiotherapy on the pulp status of posterior teeth in patients with malignant oral and oropharyngeal cancer. METHODS: Twenty-one patients diagnosed with malignant oral and oropharyngeal cancer undergoing concurrent chemoradiotherapy underwent cold thermal pulp sensitivity testing and electric pulp testing of 4 teeth, 1 from each quadrant, at 4 points in time (PT): before radiotherapy (PT1), after 30-35 Gy (PT2), at the end of radiotherapy at 66-70 Gy (PT3), and 4 months (PT4) after beginning radiotherapy. RESULTS: All 84 teeth tested positive to cold thermal pulp sensitivity testing at PT1 (100%) and 25 teeth at PT2. No tooth responded at PT3 and PT4 (100%). A statistically significant difference (P < .05) existed in the number of positive responses between different points in time. CONCLUSIONS: Radiotherapy decreased the number of teeth responding to pulp sensitivity testing after doses greater than 30-35 Gy.

Comparison of Preoperative Oral Ketorolac on Anesthetic Efficacy of Inferior Alveolar Nerve Block and Buccal and Lingual Infiltration with Articaine and Lidocaine in Patients with Irreversible Pulpitis: A Prospective, Randomized, Controlled, Double-blind Study.

INTRODUCTION: Irreversible pulpitis (IP) commonly results in decreased anesthetic efficacy of the inferior alveolar nerve block (IANB) for mandibular molar. It has been shown that supplementary buccal and/or lingual infiltration as well as premedication with ketorolac result in improved efficacy of the IANB. METHODS: One hundred fifty emergency patients who had their lower first or/and second molar diagnosed with IP participated in the study. All patients were randomly divided into 2 major IANB groups: 1 group received 4% articaine with 1:100,000 epinephrine, and the other group received 2% lidocaine with 1:80,000 epinephrine. Each group was further divided into 3 subgroups of 25 each: (1) buccal and lingual infiltration with articaine and lidocaine, respectively; (2) preoperative oral medication of ketorolac; and (3) preoperative oral medication of ketorolac followed by buccal and lingual infiltration with articaine and lidocaine, respectively. Endodontic access was initiated 15 minutes after solution deposition, and all patients were required to have profound lip numbness. Success of the anesthetic was defined as none or mild pain on endodontic access and initial instrumentation. RESULTS: Statistical analysis was performed using multiple-comparison analysis of variance (Kruskal-Wallis) and t tests. Articaine IANB with infiltrations plus oral ketorolac premedication significantly increased the success rate to 76%. The success rate after the administration of an articaine IANB with infiltration injections was 64%, whereas with lidocaine it was 32% (P < .05). CONCLUSIONS: Premedication with ketorolac significantly increases the anesthetic efficacy of articaine IANB plus infiltration in mandibular molars with IP.

Radiation-induced dental caries, prevention and treatment - A systematic review.

Treatment of head and neck cancers (HNCs) involves radiotherapy. Patients undergoing radiotherapy for HNCs are prone to dental complications. Radiotherapy to the head and neck region causes xerostomia and salivary gland dysfunction which dramatically increases the risk of dental caries and its sequelae. Radiation therapy (RT) also affects the dental hard tissues increasing their susceptibility to demineralization following RT. Postradiation caries is a rapidly progressing and highly destructive type of dental caries. Radiation-related caries and other dental hard tissue changes can appear within the first 3 months following RT. Hence, every effort should be focused on prevention to manage patients with severe caries. This can be accomplished through good preoperative dental treatment, frequent dental evaluation and treatment after RT (with the exception of extractions), and consistent home care that includes self-applied fluoride. Restorative management of radiation caries can be challenging. The restorative dentist must consider the altered dental substrate and a hostile oral environment when selecting restorative materials. Radiation-induced changes in enamel and dentine may compromise bonding of adhesive materials. Consequently, glass ionomer cements have proved to be a better alternative to composite resins in irradiated patients. Counseling of patients before and after radiotherapy can be done to make them aware of the complications of radiotherapy and thus can help in preventing them.

Histological analysis of cleaning efficacy of hand and rotary instruments in the apical third of the root canal: A comparative study.

AIM: To compare the cleaning efficiency of manual and rotary instrumentation in the apical third of the root canal system. MATERIALS AND METHODS: In group 1 (n=10), instrumentation was performed with stainless steel K-file; in group 2 (n=10), it was done with hand ProTaper files; and in group 3 (n=10), instrumentation was done with ProTaper rotary. Distilled water was used for irrigation. The apical third was sectioned transversally and histologically processed. The cross sections were examined under optic microscope and debris was measured using Motic software. RESULTS: Instrumentation with stainless steel K-files showed minimum amount of debris, followed by ProTaper hand files, and rotary ProTaper files were least effective with maximum amount of debris; however, there were no significant differences between the three experimental groups. CONCLUSIONS: Both the manual and rotary instrumentation are relatively efficient in cleaning the apical third of the root canal system and the choice between manual and rotary instrumentation should depend on case to case basis.