Antibiofilm activity of ultrasonic and diode laser activated sodium hypochlorite, chitosan, and chlorhexidine: A confocal laser scanning microscopic in vitro study.

Aim: The aim of this study was to assess and compare the effect of ultrasonic and diode laser-activated sodium hypochlorite (NaOCl), chitosan, and chlorhexidine (CHX) on the removal of Enterococcus faecalis biofilm adherent to the root canal using a confocal laser scanning microscope (CLSM). Materials and Methods: Root canals in 112 single-rooted teeth were instrumented using a rotary Ni-Ti system. Biofilms of E. faecalis were generated based on an established protocol. Samples were randomly divided into three experimental (n = 28) and one control (n = 28) group based on the irrigation protocol employed and the three experimental groups were further subdivided into subgroups based on the activation protocol (subgroup A - ultrasonic activated and subgroup B - diode laser activated). The groups were Group 1 (control), Group 2 (3% NaOCl for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), Group 3 (2% CHX for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation), and Group 4 (0.2% chitosan for 6 min; subgroup A - activated using a diode laser, subgroup B - ultrasonic activation. Confocal laser scanning microscopy was used to assess bacterial viability in situ. Data were analyzed by appropriate statistical analyses with P = 0.05. Results: All experimental irrigation protocols destroyed the biofilm in the root canal lumen. Within the dentinal tubules, all groups had a significantly higher percentage of dead bacteria than the saline control (P < 0.05). There was no significant difference between CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), whereas NaOCl ultra and NaOCl diode groups brought about more bacterial reduction than other groups (P < 0.05). The mean effectiveness and the bacterial kill ability were seen highest for the NaOCl activated with the ultrasonics group. There was no significant difference between diode laser activation and ultrasonic activation in CHX activated with ultrasonics, CHX activated with a diode laser, chitosan activated with ultrasonics and chitosan activated with diode laser groups (P > 0.05), but there was a significant difference between diode laser and ultrasonic activation in NaOCl group. Ultrasonic activation of the NaOCl was more effective than diode activation in reducing E. feacalis biofilms (P < 0.05). Conclusions: The use of NaOCl with the activation by ultrasonics caused the greatest reduction of E. faecalis. Ultrasonic activation was found superior to diode laser activation in dentinal tubule disinfection.

Influence of Various Desensitizing Mouthrinses and Simulated Toothbrushing on Surface Roughness and Microhardness of Tetric N-Ceram Bulk-Fill Resin Composite: An In Vitro Study and Scanning Electron Microscope Analysis.

OBJECTIVES: Bulk-filled composite resins are popularly used for posterior restorations due to various advantages. Routine oral hygiene measures like toothbrushing and the use of various mouthrinses can influence the mechanical properties of composite resins. Desensitizing mouthrinses are widely used as well, to manage dentinal hypersensitivity. Studies on the influence of desensitizing mouthrinses on bulk-filled composites are limited. Hence, the objective of the present in vitro study was to evaluate the influence of toothbrushing and various desensitizing mouthrinses on the surface roughness and microhardness of Tetric N-Ceram bulk-fill composite resin. MATERIALS AND METHODS: Fifty Tetric N-Ceram bulk-fill composite resin disks were prepared and were randomly divided into five groups (n = 10). Group 1 (Control): no toothbrushing and no mouthrinse; Group 2: toothbrushing only; Group 3: toothbrushing + HiOra-K mouthrinse; Group 4: toothbrushing + Listerine Sensitive mouthrinse; and Group 5: toothbrushing + Shy-OR mouthrinse. The specimens were brushed with a soft bristle brush using a toothpaste slurry and immersed in respective mouthrinse twice daily for 1 month. The mean surface roughness (average roughness) and microhardness (Vickers Pyramid number) values were determined and the data were tabulated. Data were analyzed using one-way analysis of variance, Post-hoc Tukey test, and Pearson correlation test. A p-value less than 0.05 was considered statistically significant. RESULTS: Specimens treated with HiOra-K mouthrinse exhibited maximum surface roughness (p < 0.05) and specimens treated with Listerine Sensitive exhibited the least microhardness (p < 0.05). A weak negative correlation was found between surface roughness and microhardness for groups 1, 2, and 5, while a weak positive correlation was found for groups 3 and 4. CONCLUSIONS: It is suggested that desensitizing mouthrinses containing alcohol or essential oils can lead to increased surface roughness and reduction in microhardness of bulk-fill composites, which could have an undesirable effect on their clinical performance.

PCR-based detection of three anaerobic bacteria associated with endodontic-periodontic lesions in type-2 diabetic and nondiabetic subjects.

AIM: The aim of this study is to clinically isolate and detect three anaerobic bacteria associated with endodontic-periodontal lesions in type-2 diabetic and nondiabetic patients using polymerase chain reaction (PCR). MATERIALS AND METHODS: Sixty patients presenting endodontic-periodontal lesions were divided into two groups. Thirty patients with type-2 diabetics (Group 1) and 30 nondiabetic patients (Group 2) were evaluated for the presence of three anaerobic bacteria. Clinical examinations, periapical radiographs, and microbiological sampling from the canal system and periodontal pockets were performed. Qualitative evaluation of bacteria was performed using a multiplex PCR for Porphyromonas gingivalis and Prevotella intermedia. Statistical analysis was performed using Pearson's Chi-square test and Fischer's exact test. RESULTS: Enterococcus faecalis (73.3%) was the predominant bacteria isolated from the root canal in type 2 diabetic patients, followed by P. gingivalis (70%) and P. intermedia (36%) compared to 53.3%, 43.3%, and 23.3%, respectively, among nondiabetic patients. P. gingivalis (73.3%) was the predominant bacteria isolated from periodontal pockets in type II diabetic patients followed by P. intermedia 50% and E. faecalis 30% compared to 36.6%, 33.3%, and 30%, respectively, among nondiabetics. P. gingivalis was detected in the root canal and periodontal pocket in almost similar numbers (70% and 73%), respectively, among type-2 diabetics. CONCLUSION: Detection of P. gingivalis, P. intermedia, and E. faecalis in both root canal and periodontal pocket samples confirm a viable pathway for the spread of infection through dual sites. Since in the present study, P. gingivalis was found to be present in similar numbers in dual sites among type 2 diabetic patients, importance should be given in treating such anaerobic bacteria in immune-compromised patients.

Comparative Evaluation of Cytotoxicity and Genotoxicity of Two Bioceramic Sealers on Fibroblast Cell Line: An in vitro Study.

AIM: The purpose of this study was to evaluate and compare the cytotoxicity and genotoxicity of two bioceramic root canal sealers: EndoSequence BC and iRoot SP with zinc oxide eugenol sealers on fibroblast cell line. MATERIALS AND METHODS: The sealers tested were zinc oxide eugenol, EndoSequence BC, and iRoot SP. Each material was mixed according to the manufacturer's instructions and mounted into sterile polyethylene color-coded rings, for cytotoxicity and genotoxicity evaluation. After 48 hours, the set materials were transferred to previously marked wells and cytotoxicity evaluation to L929 murine fibroblast cells was done by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. The percentages of viable cells were then calculated and values were statistically analyzed by Kruskal-Wallis test. The evaluation of genotoxicity of the materials to L929 murine fibroblast cells was carried out by Comet assay. To quantify deoxyribonucleic acid (DNA) damage, the following comet parameters were evaluated in the assay using Comet scoring software: tail length, tail moment, and Olive moment. The values were statistically analyzed using Kruskal-Wallis test with a significance value set to p < 0.05. RESULTS: The results of the study showed that both cytotoxicity and genotoxicity evaluation by MTT assay and Comet assay can be done on L929 murine fibroblast cell line. Among the three tested materials, zinc oxide eugenol showed maximum cytotoxicity to the cells (30.64% viable cells), followed by EndoSequence BC (71.33% viable cells) and iRoot SP (75.11% viable cells). The evaluation of DNA damage by genotoxicity assessment showed iRoot SP to be least genotoxic followed closely by EndoSequence BC. Zinc oxide eugenol was genotoxic and induced more DNA damage on the fibroblast cell line studied. The statistical analyses for both the assays were nonsignificant. CONCLUSION: All the three tested sealers showed varying degrees of cytotoxicity and genotoxicity while using fibro-blast cell line. Zinc oxide eugenol was most toxic in both the assays and iRoot SP showed least toxicity, followed closely by EndoSequence BC.