Evaluation of the Flexural Strength of Submicron Hybrid Composite using Different Fabrication Methods: An in vitro Study.

AIM: The aim of this study is to perform three-point bend test on submicron hybrid composite fabricated with direct and indirect veneer technique. MATERIALS AND METHODS: A total of 20 maxillary anterior teeth were selected, and labial reduction of 0.5 to 0.75 mm with a chamfered finish line for veneer preparation was done. Teeth were divided into two groups depending on fabrication technique being used: group I-veneers fabricated with light and group II-veneers fabricated with light and heat (PHOTOPOL). Specimens were tested under universal testing machine (UTM) where load was applied at a crosshead speed of 1 mm/min with a pointer of 1 mm diameter. Data were statistically analyzed. RESULTS: The results showed highly significant difference between the two groups with the mean value of group I (246.7 ± 2.285 N) and group II (531.1 ± 4.411 N). CONCLUSION: The curing mechanism involving light and heat increases the fracture resistance of the veneers. CLINICAL SIGNIFICANCE: Within the limitations of this study, the results led to the conclusion that the association of common composites with a simple postcure heat treatment may be an alternative for current indirect composite systems, although more studies are needed to assess other properties of the composites for this application.

Comparative Evaluation of the Efficacy and Onset of Local Anesthesia Using Buffered 2% Lidocaine with 1:100,000 Adrenaline, Non-buffered 2% Lidocaine with 1:100,000 Adrenaline, Buffered 4% Articaine with 1:100,000 Adrenaline and Non-buffered 4% Articaine with 1:100,000 Adrenaline in Dental Extraction.

Aim: To compare the efficacy and onset of local anesthesia using buffered versus non-buffered 2% lidocaine with 1:100,000 adrenaline and 4% articaine with 1:100,000 adrenaline in dental extraction. Methodology: A prospective, clinical study was carried out in oral and maxillofacial surgery department. Twenty-eight patients were considered in the study and were divided into 4 groups. Each group randomly received either buffered 2% lidocaine with 1:100,000 adrenaline, non-buffered 2% lidocaine with 1:100,000 adrenaline, buffered 4% articaine with 1:100,000 adrenaline or non-buffered 4% articaine with 1:100,000 adrenaline. The outcome variable was onset of anesthesia and effectiveness of anesthesia in buffered and non-buffered group. Results: Results showed that the mean onset of time and efficacy of local anesthesia was significantly better in buffered when compared with non-buffered local anesthetic solution with adrenaline. Conclusion: In conclusion, the addition of sodium bicarbonate as a buffering agent decreases time of onset and increases the effectiveness of local anesthetics, thus providing comfort to the patient. The mean onset of time for first symptom as well as lip numbness was more for non-buffered lidocaine followed by non-buffered articaine, buffered lidocaine and buffered articaine. The mean onset of time for subjective and objective symptoms was more for non-buffered anesthetic solution as compared to buffered anesthetic solution. VAS readings were not statistically significant among the four groups.

Comparison of proximal contact and contours of class II restoration in premolars and molars restored with three different matrix systems using FDI criteria: An in vivo study.

Context: Sectional matrix systems, namely, Garrison and Bioclear with contact rings, are valuable aids to establish proximal contact tightness and contours in Class II composite restorations when compared with the circumferential matrix system Tofflemire. Aims: This study aimed to compare the proximal contact and contours of Class II restoration in premolars and molars restored with Tofflemire, Garrison, and Bioclear matrix system by FDI criteria of approximal anatomical form using floss or 25-µm metal blade and radiographic examination. Subjects and Methods: Sixty Class II patients were selected, and a preoperative bitewing radiograph was taken. Initially, caries removal was done by round diamond bur, followed by 245 carbide bur. Samples were divided randomly into three groups based on the type of matrix system used for restoration. Group 1 (n = 20): Tofflemire, Group 2 (n = 20): Garrison matrix system, and Group 3 (n = 20): Bioclear matrix system. Matrix systems were applied according to the manufacturer's instructions, and composite restoration was done. The clinical evaluation of proximal contact and contour was done by a blinded observer immediately after placement of composite restoration using FDI criteria by passing dental floss or 25-µm metal blade, whereas marginal gaps and overhangs were checked using a radiograph. Results were statistically analyzed. Statistical Analysis Used: The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS for Windows, Version 19.0). Descriptive statistics was calculated as frequency and percentage. The comparison of characteristics of the contact points, contour, and radiographic examination was carried out using the Chi-square test. Multiple comparisons were done by comparing column proportions with Bonferroni adjustments. The level of significance for the present study was fixed at P < 0.05. Results: There were significantly higher proportions of normal contacts in Garrison (60%) and Bioclear (70%) compared to that in the Tofflemire (20%) matrix system (Bioclear > Garrison > Tofflemire). Comparison of contours showed normal contours with Garrison (50%), Bioclear (50%), and Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). In radiographic examination, harmonious transitions between the restoration and the tooth were similar in Garrison (30%) and Bioclear (30%) compared to the Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). Conclusions: Garrison and Bioclear sectional matrix systems established superior contacts and contours than the Tofflemire circumferential system.

An In Vitro Study Comparing the Antimicrobial Efficacy of 0.2% Chitosan, 3% Sodium Hypochlorite, 2% Chlorhexidine against Enterococcus faecalis, Alone and in Conjunction with Diode Laser.

The aim and objective of this study was to compare the antimicrobial efficacy of 0.2% chitosan, 3% sodium hypochlorite, 2% chlorhexidine against Enterococcus faecalis, alone and in conjunction with diode laser. Materials and methods: The root canals of 72 extracted intact human single-rooted teeth with single canals were prepared, and E. faecalis was incubated in the root canals for 7 days. The teeth were then randomly divided into the following four experimental groups: group I: Saline, group II: 0.2% Chitosan, group III: 3% Sodium hypochlorite, and group IV: 2% Chlorhexidine. These groups were further subdivided into three groups: (1) 10 mL irrigant only, (2) 10 mL irrigant, dried and irradiation with diode laser, (3) Diode laser was used for activation of irrigant solution. Samples were obtained from subgroups in each group and checked for turbidity. The effect of each irrigant was evaluated by counting the number of colony-forming units observed on inoculation with samples taken from the irrigated canal on bile esculin azide agar. The data thus obtained was recorded and put to statistical analysis. Results: Significant reductions were noted in E. faecalis colony counts in all groups (p < 0.05). The greatest reduction in colony count (0%) was noted in group IV followed by group II. Also, samples disinfected with diode laser after root canal irrigation showed less number of colony-forming units per mL as compared to the samples irrigated with root canal solutions alone or diode laser alone. Conclusion: Chitosan has the capability for use as an accessory for disinfection of the root canal system. The application of an 810-nm diode laser by itself did not have the adequate antimicrobial activity to be used as an adjunct in root canal therapy. Irradiation with diode laser ought to be used in conjunction with the irrigant to gain maximum antibacterial effect against E. faecalis. How to cite this article: Goel P, Galhotra V, Makkar S, et al. An In-vitro Study Comparing the Antimicrobial Efficacy of 0.2% Chitosan, 3% Sodium Hypochlorite, 2% Chlorhexidine against Enterococcus faecalis, Alone and in Conjunction with Diode Laser. Int J Clin Pediatr Dent 2022;15(1):109-114.

Effect of Distinctive Moisture Conditions on Push-out Bond Strength of Three Root Canal Sealers-An In-Vitro Study.

OBJECTIVE: Endodontic sealer should adhere to both dentin and the core filling material but the moisture conditions of the canals affect the adhesive properties of the sealer. An ideal sealer with perfect moisture conditions will lead to greater strength of the restored tooth, which may provide greater resistance to tooth fracture and clinical longevity of an endodontically treated tooth. The aim of this study was to evaluate the effect of moisture conditions on the push-out bond strength of three root canal sealers: AH Plus® (Dentsply-Tulsa Dental, Tulsa, OK), Epiphany (Pentron Clinical Technologies, Wallingford, CT), and GuttaFlow (Coltene/Whaledent, Altstatten, Switzerland). MATERIALS AND METHODS: A total of 120 single-rooted, non-carious teeth were collected for the study and were stored in normal saline. The root canals were prepared using step-back technique. Teeth were divided into four groups based on type of drying procedure used and further subdivided into three subgroups based on the type of sealer used. The samples were cut horizontally to produce slices and then tested for push-out bond strength using Universal Testing Machine (Servo Series 50 kN; P S I Sales Private Limited, New Delhi, India). The specimens were examined for mode of fracture under magnification and the results were analyzed statistically. RESULTS: Distinctive moisture conditions for all sealers were observed and the highest strength of AH Plus® was evaluated under moist condition, Epiphany under dry condition, and GuttaFlow under normal condition, respectively. CONCLUSION: Distinctive moisture conditions affect the push-out bond strength of the sealers.

Pressure alteration techniques in endodontics- a review of literature.

The triad of biomechanical preparation, pulp space sterilization and three-dimensional obturation is the hallmark of endodontic success. Complete disinfection of the pulp space cannot be achieved with most sophisticated instrumentation techniques. The role of irrigants in obtaining this goal cannot be underestimated. Optimal irrigation is based on the combined use of two or several irrigating solutions, in a specific sequence. Today's irrigation armamentarium presents a diverse variety of tools and techniques that can assist the practitioner in reducing bacteria and debris within the canal system. However, currently there is no universally accepted standard irrigation technique. The aim of this article is to review armamentarium and various irrigants in endodontic practice.

Comparative evaluation of surface properties of enamel and different esthetic restorative materials under erosive and abrasive challenges: An in vitro study.

INTRODUCTION: Noncarious tooth surface loss is a normal physiological process occurring throughout the life, but it can often become a problem affecting function, esthetics or cause pain. AIM: The purpose of this study was to assess the effect of erosive and abrasive challenges on the surface microhardness and surface wear of enamel and three different restorative materials, that is, nanofilled composite, microfilled composite and resin-modified glass ionomer cement (RMGIC) by using Vickers microhardness tester and profilometer respectively. SUBJECTS AND METHODS: Nanofilled composite (Filtek(™) Z350 × T), microfilled composite (Heliomolar(®)) and RMGIC (Fuji II LC) were used in the study. RESULTS: Nanofilled composite resin has the best resistance to erosion and/or abrasion among all the materials tested, followed by microfilled composite and RMGIC respectively. CONCLUSION: Toothbrush abrasion has a synergistic effect with erosion on substance loss of human enamel, composites, and RMGIC. The susceptibility to acid and/or toothbrush abrasion of human enamel was higher compared to restorative materials.

Effect of desensitizing treatments on bond strength of resin composites to dentin - an in vitro study.

OBJECTIVES: Hypersensitivity is a common clinical multietiological problem. Many desensitizing treatments are there to overcome hypersensitivity. The aim of this study was to evaluate the effect of different dentin-desensitizing treatments on the tensile bond strength of composite restoration. MATERIALS AND METHODS: Twenty-four sound human molars were used. Enamel was wet abraded to expose flat dentin surfaces, polished with sandpaper. The specimens were then divided into three groups (n = 8) based on the type of dentin-desensitizing treatment given. The first group: G1 was the control group where no desensitizing agent was used. The second group: G2 was treated with desensitizing dentifrice containing a combination of potassium nitrate, triclosan, and sodium monoflorophosphate. The third group: G3 was treated with Er:YAG laser. Afterwards, the desensitized specimens were treated with one step self-etch adhesive according to manufacturer's instructions and composite microcylinders were packed. The specimens were then examined for tensile bond strength using universal tensile machine (KMI(TM) ). RESULTS: Statistical analysis of the data obtained revealed the mean values for the tensile bond strengths were 10.2613 MPa, 5.9400 MPa and 6.3575 MPa for groups 1, 2 and 3, respectively. These values were statistically significantly different between groups pretreated with laser or dentifrice as compared to control group. CONCLUSIONS: Dentifrice and Laser pre-treated dentin has lower tensile bond strength with resin composites as compared to dentin that is untreated.