Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study.

AIM: To assess the effectiveness of various surface treatments and adhesives on the bond strength of zirconia-based ceramic to dentin. MATERIALS AND METHODS: Eighty samples of zirconia were subjected to the four-surface treatment protocols (sandblasting, 48% hydrofluoric acid (HF), 48% hydrofluoric acid + 70% nitric acid (HNO3) and no treatment (control) following which the samples from each group were subdivided into two subgroups (n = 10) based on the resin cement employed for cementation (RelyX U200 and G-Cem Linkforce). The bonded specimens were subjected to shear stress to measure the bond strength using Universal testing machine. To test the difference in bond strength among the eight study groups, the Kruskal-Wallis ANOVA test was applied and for comparison between cements in each group, Mann-Whitney U test was applied. RESULTS: The highest bond strength values were observed for 48% HF group cemented with G-Cem Linkforce resin cement (16.220 ± 1.574) and lowest for control group-RelyX (4.954 ± 0.972). G-Cem cement showed higher bond strength than RelyX for all surface treatments except 48% HF + 70% nitric acid. CONCLUSION: It can be inferred that 48% HF can etch zirconia and generate a porous structure that proves to be beneficial for bonding. CLINICAL SIGNIFICANCE: The increasing demand for esthetics has led to the replacement of metal-ceramic materials with zirconia-based ceramics. However, the chemical inertness of zirconia to various conventional surface treating agents has continuously challenged researchers to discover a new surface treatment protocol that could enhance the bond strength of zirconia. How to cite this article: Yenamandra MS, Joseph A, Singh P, et al. Effect of Various Surface Treatments of Zirconia on its Adhesive Properties to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):226-230.

Effectiveness of 38% Silver Diamine Fluoride Application along with Atraumatic Restorative Treatment for Arresting Caries in Permanent Teeth When Compared to Atraumatic Restorative Treatment in Adults-Study Protocol for a Randomized Controlled Trial.

INTRODUCTION: Dental caries in the adult population that require preventive and therapeutic treatment are generally neglected in rural communities. The determination of the effectiveness of the application of 38% silver diamine fluoride (SDF) in arresting caries lesions when combined with atraumatic restorative treatment (ART) is very important, as it serves as a preventive and restorative procedure to regain the function of the permanent dentition. The assessment of optimal SDF application with ART, in comparison with ART alone, in managing cavitated carious lesions in a pragmatic setting, is the need of the hour to recommend optimal dental care, especially in rural settings which have minimal access to comprehensive dental care. METHODS AND ANALYSIS: The clinical trial will enrol 220 adults (18-65 years) with cavitated carious lesions attending the Amrita School of Dentistry in the Ernakulam district, India. This study is a randomized, controlled trial with a 1:1 allocation ratio in two parallel groups. Study arm 1 will receive 38% SDF application and ART, and study arm 2 will receive ART only. A digital radiograph will be taken immediately after restoration (baseline) as well as at the end of the 6th month for evaluation of caries arrest. The assessment of the survival of the restoration will be done on the 7th day, 30th day, and at the end of the 6th month. The final analysis would include both the tooth and person levels. ETHICS AND DISSEMINATION: This trial adheres to the principles of the Declaration of Helsinki and the guidelines of the Indian Council of Medical Research (ICMR). This study protocol has been approved by the Institutional Review Board. This trial has been registered prospectively with the Clinical Trial Registry of India (Registration No: CTRI/2021/12/038816).

Comparative Evaluation of Root Canal Centering Ability of ProTaper, Mtwo, WaveOne, and Reciproc Using Cone-beam Computed Tomography: In Vitro Study.

AIM: To compare the centering ability of rotating (ProTaper and Mtwo) and reciprocating (WaveOne and Reciproc) file systems using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Eighty extracted human mandibular molars with curvature within 15-45° were selected and randomly divided into four groups (n = 20): group I (ProTaper), group II (Mtwo), group III (WaveOne), and group IV (Reciproc). The selected teeth were arranged in a template, and pre-instrumentation and post-instrumentation CBCT scans were taken using Kodak Carestream CS 9300 machine. The centering ability was measured in four planes namely, at furcation, 3 mm apical to furcation (coronal), 6 mm apical to furcation (middle), and 3 mm coronal to the apex (apical), wherein dentin thickness was measured from pre- and post-instrumentation CBCT scans and recorded for each canal (mesiobuccal and mesiolingual) separately and statistically analyzed. RESULTS: Mtwo and Reciproc remained better centered followed by WaveOne and least by ProTaper in different-level comparisons. In the mesiodistal dimension (MD) at the 3 mm, 6 mm, and 3 mm apical level, Mtwo and Reciproc showed better centering, meanwhile, in the buccolingual dimension, only in the 3 mm apical level, Mtwo and Reciproc remain better centered. A significant difference was seen between the group and type of canal. CONCLUSION: Mtwo and Reciproc showed better centered preparation than ProTaper and WaveOne. Significant differences were seen between the groups and types of canal. CLINICAL SIGNIFICANCE: Root canal instrumentation should maintain the original canal anatomy. The proper enlargement keeping in mind the remaining strength in the tooth structure is essentially decided by how the selected instrument is centered. The alloy used for instrument manufacture and its design (taper, cross-section, and tip) will influence the centered preparation. The type of instrument and the instrumentation techniques should be chosen based on root canal anatomy.

Evaluation of the efficacy of different intracanal medicaments against Candida albicans and Enterococcus faecalis - An In-Vitro study.

Aim: This study aims to evaluate the antimicrobial efficacy of certain intracanal medicaments against Candida albicans and Enterococcus faecalis. Methods: Freshly extracted 120 single rooted mandibular premolars were selected for the study. Teeth were decoronated and cleaning and shaping was done up to F3 universal protaper system and were divided mainly into two groups: Candida albicans (C. albicans) (n = 60) and Enterococcus faecalis (E. faecalis) (n = 60). The medicaments include: G1: chlorhexidine + calcium hydroxide, G2: sodium hypochlorite + calcium hydroxide, G3: 2% chlorhexidine gel, G4: octenisept, G5: 0.1% octenisept solution + calcium hydroxide, and G6: physiologic saline (n = 5). Teeth were contaminated with Enterococcus faecalis and Candida albicans which were cultured, respectively, in brain heart infusion and Sabouraud's dextrose agar for 21 days followed by intracanal medication and colony forming units were counted on the second and seventh day. Statistical analysis was done using Analysis of Variance (ANOVA) and Tukey's post hoc test. Results: Against C. albicans, CHX + CH, 2% CHX gel, 0.1% octenidine (OCT) gel and OCT + CH showed statistically significant differences on the 2nd and 7th day. But against Enterococcus faecalis, only 0.1% OCT gel and 2% CHX gel showed statistically significant differences on the 2nd and 7th day. Among all the groups, 0.1% OCT gel and 2% CHX gel showed predominant antimicrobial efficacy. Conclusion: From the limitations of the current study, all the medicaments showed antimicrobial effect against Candida albicans and Enterococcus faecalis on the 2nd and 7th day with higher microbial inhibition on the 7th day.

Drug Repurposing for Tooth Regeneration: The Promising Premises.

Drug repurposing which identifies new therapeutic use(s) for drugs currently in use is a brand-new avenue of research interest worldwide. It circumvents the high-end monetary and time investment usually associated with contemporary drug discoveries. In the field of dentistry, recent studies in drug repurposing focuses in attaining dentin repair or reduction of bone resorption associated with apical periodontitis. Metformin, an anti-diabetic drug has shown pro-osteogenic properties. Aspirin a known anti-inflammatory agent with anticoagulant action is found to modulate the differentiation of dental pulp cells. The significant role of glycogen synthase kinase-3 inhibitors in activating the Wnt/-beta cat signaling pathway of mesenchymal pulp stem cells may pave the way to the pharmacological treatment of dental caries in near future. It is to be noted here that further preclinical and clinical studies are warranted for the regular therapeutic use of these potential drugs in clinical dentistry.

Comparative Evaluation of Microcrack Formation in Different Kinematics Using Rotary and Reciprocating File Systems: An In Vitro Study.

AIM AND OBJECTIVE: To compare r oot microcrack formation after r oot canal preparation using ProTaper Next in r otation or forward r eciprocation and Waveone gold in r everse r eciprocating motion. MATERIALS AND METHODS: Buccal r oots of 60 maxillary premolars with mature apices were selected, for different instrumentation techniques and divided into three groups. Coronal access was achieved and the canals were confirmed for apical patency. The canals were then instrumented using the following instrumentation techniques: ProTaper Next in r otation or forward r eciprocation or Waveone gold in r everse reciprocation. The tooth was then subjected to sectioning using a diamond saw under water cooling and then was visualized under the stereomicroscope for dentinal microcrack. RESULTS: The results showed that the maximum dentinal microcrack formed at apical 3 and 6 mm was in Waveone gold in reverse reciprocation followed by ProTaper Next in forward reciprocation and rotation. However, the p value was found to be not significant at 3 and 6 mm (p value-0.082 and 0.23). CONCLUSION: Nickle titanium rotary instruments tend to induce varied degrees of root dentinal damage during canal instrumentation. ProTaper Next files in rotation as well as forward reciprocation presented with minimal microcrack defects when compared with Waveone gold. CLINICAL SIGNIFICANCE: Root canal preparation, when performed by manual or engine-driven techniques, has shown to produce structural defects in the root dentin. One of the causes of failures in root canal treatment is because of fracture in the dentin that occurs due to these procedures. Though all the motion kinematics caused microcracks in this study, it was seen that rotational motion produced the least structural damage to the dentin.

Effect of Instrumentation Techniques and Kinematics on Apical Extrusion of Debris: An In Vitro Study.

AIM: To evaluate the effect of instrumentation kinematics on debris extrusion by comparing the amount of apically extruded debris after canal preparation using ProTaper next in continuous rotation as well as forward reciprocating motion and WaveOne gold in reverse reciprocating motion. MATERIALS AND METHODS: We randomly divided ninety buccal roots of maxillary bicuspids with fully formed apices into three groups. After achieving the coronal access, the patency of the root canals was established with a size 10 K file. The canals were then instrumented using ProTaper next in continuous rotation or in a forward reciprocating motion and WaveOne gold in reverse reciprocating motion. Eppendorf tubes were used to collect the debris extruded through the apical foramen. The tubes were placed in a -80° freezer for 8 hours and then in a lyophilizer for 24 hours. The quantity of the apically extruded debris was assessed by subtracting the weights of Eppendorf tubes before and after instrumentation. The analysis was done using a one-way ANOVA test and the Bonferroni test to compare the groups. RESULTS: The mean weight of extruded debris with WaveOne gold in reverse reciprocation was significantly lower than ProTaper next in forward reciprocation and ProTaper next in continuous rotation (p value = <0.001). CONCLUSION: WaveOne gold in reverse reciprocation was associated with a significantly lower amount of apical extrusion of debris than ProTaper next rotary files in forward reciprocation and continuous rotation. CLINICAL SIGNIFICANCE: According to the results of this study, reciprocating instrumentation technique was associated with a less amount of debris extrusion compared to continuous rotation.

Effect of 2% Chlorhexidine on Resin Bond Strength and Mode of Failure Using Two Different Adhesives on Dentin: An In Vitro Study.

AIM: To evaluate the shear bond strength and failure mode of total-etch and self-etch bonding agents on human dentin with and without application of 2% chlorhexidine gluconate (CHX). MATERIALS AND METHODS: Eighty extracted premolars were chosen and stored in 10% formalin until use. Samples were mounted in cold cure acrylic resin and the occlusal enamel perpendicular to long axis of each tooth was removed using a low-speed diamond saw under water coolant. The prepared teeth were randomly divided into four groups of 20 samples each according to the adhesive system used. Groups 1 and 2 were the control group in which total-etch and self-etch adhesives were applied as per manufacturer's instructions, Groups 3 and 4 were the experimental groups in which 2% CHX was applied and blot dried prior to the application of total-etch and self-etch adhesives. A custom-designed rig was fabricated to place composite on samples. The customized rig comprised a cylindrical mold with height of 3 mm and internal diameter of 2.5 mm. Resin was placed in increments of 1 mm and was cured after each increments. After the composite placements, samples were placed in distilled water at 37°C for 24 h. The samples were then thermocycled between 5°C and 55°C in water with a dwell time of 30 s in each temperature to a total of 10,000 cycles. The shear test was performed using universal testing machine and fracture modes were evaluated using stereomicroscope. RESULTS: Both the experimental total-etch and self-etch groups showed better shear bond strength than the control groups, which was statistically significant, and also the least mode of failure at the adhesive interface was observed in both the experimental groups. CONCLUSION: 2% Chlorhexidine gluconate effectively improved the shear bond strength and helped maintaining the durability of adhesive interface in both total-etch and self-etch adhesives.

Gingival vitiligo: report of a case and review of the literature.

Rarely cases have been reported regarding depigmented lesions of the oral cavity. On reviewing the literature, only few cases of gingival vitiligo or similar lesions have been reported till date. These lesions pose a cosmetic challenge. We present here a case of vitiligo affecting gingiva. Vitiligo has been defined as an acquired, slowly progressive loss of cutaneous pigment which occurs as irregular, sharply defined patches which may or may not be surrounded by macroscopic hyperpigmentation. Differential diagnosis, detailed clinical history, histopathology, immunohistochemistry, and pathogenesis of this condition are discussed.

Sealing ability of mineral trioxide aggregate, calcium phosphate cement, and glass ionomer cement in the repair of furcation perforations.

OBJECTIVES: The purpose of this study was to evaluate the in vitro sealing ability of three repair materials. Mineral trioxide aggregate (MTA; Group A), calcium phosphate cement (CPC; Group B), and light cured glass ionomer cement (GIC; Group C) when used to repair the perforation created in the pulpal floor of fifty extracted human permanent molars. MATERIALS AND METHODS: Preparation of access openings and furcation perforations were done, and the teeth divided into five experimental groups (A, B, C) including two controls (D, E) with ten samples in each group randomly. Following the repair procedure, the pulp chambers and access openings were filled with composite resin and immersed in 2% methylene blue solution for 48 hours. The teeth were sectioned longitudinally and the linear dye penetration measured under a stereomicroscope. RESULTS: The comparison of the linear length of micro-leakage (mm) among the experimental groups revealed no significant difference (p = 0.332). On calculating the percentage of depth of leakage to the total length of the perforation, it was observed that the mean leakage was 35.5% in Group A, 53.6% in Group B and the highest, 87.5% in Group C. The mean of leakage percentage was statistically significant by Kruskal-Wallis test (p = 0.003). The results indicated that the dye penetration used as furcation perforation repair material was least with mineral trioxide aggregate. Comparing the depth of penetration of dye, 50% of the Group A samples showed less than 25% of depth penetration. While 40% of Group B cases had more than 50% dye penetration. In our study, all Group C teeth had > or = 50% dye penetration. CONCLUSIONS: The present study indicated that GIC had the greatest dye penetration followed by CPC and MTA. Mineral trioxide aggregate and calcium phosphate cement had comparatively better sealing ability than glass ionomer cement.