Comparative Efficacy of Resin Infiltrant and Two Remineralizing Agents on Demineralized Enamel: An In Vitro Study.

AIM: To compare and evaluate the caries preventive effectiveness of resin infiltrant (ICON), casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (GC Tooth Mousse), and nanohydroxyapatite (Aclaim) on incipient enamel lesions. MATERIALS AND METHODS: A total of 60 human maxillary incisors extracted for periodontal reasons were included in this study. The sectioning was done at the middle third region of the crown for the 60 samples with approximate dimensions of 5 × 5 × 5 mm). In order to create the artificial enamel lesions, the samples were demineralized by placing in a beaker containing the prepared demineralizing solution for 14 days. The study samples were then divided into four groups that are resin infiltrant (group I), CPP-ACP (group II), nanohydroxyapatite (group III), and control (group IV) with 15 enamel samples in each group. The caries preventive efficacy of each group was evaluated using a confocal laser scanning microscope. RESULTS: The mean values after demineralization of enamel samples in demineralizing solution are 245 µm for resin infiltrant (group I), 246 µm for CPP-ACP (group II), 250 µm for nanohydroxyapatite (group III), and 247 µm for control (group IV). After remineralizing the enamel samples for a period of 30 days, the results are group I (resin infiltrant) 158 µm > group II (CPP-ACP) 28.8µm ≥ group III (nanohydroxyapatite) 26.3 µm. After subjecting it to demineralizing solution again for 14 days, the amount of material that was resistant to acid attack was group I (resin infiltrant) 114 µm (72%) > group III (CPP-ACP) 16.4 µm (57%) ≥ group III (nanohydroxyapatite) 13.8 µm (50%). The untreated control group showed increased progression of lesion and least resistance to acid challenge. CONCLUSION: Based on the results from this in vitro study, it can be concluded that when compared to the two remineralizing agents the resin infiltrant showed better caries preventive effectiveness. CLINICAL SIGNIFICANCE: Resin infiltrants have a favorable penetration potential in subsurface or incipient enamel lesions.

Evaluation of the Antibacterial Efficiency of a Combination of 1% Alexidine and Sodium Hypochlorite on Enterococcus faecalis Biofilm Models: An In Vitro Study.

AIM: The aim of the study was to assess the antibacterial efficiency of a combination of 1% alexidine (ALX) and 5.25% sodium hypochlorite (NaOCl) against E. faecalis biofilm using a confocal scanning electron microscopy. MATERIALS AND METHODS: An estimated 120 human root dentin disks were prepared, sterilized, and inoculated with E. faecalis strain (ATCC 29212) to develop a 3-weeks-old biofilm. The dentin discs were exposed to group I-control group: 5.25% sodium hypochlorite (NaOCl) (n = 20); group II-1% ALX + 5.25% NaOCl (n = 40); group III-1% alexidine (ALX) (n = 40) (Sigma-Aldrich, Mumbai, India); group IV-negative control: saline (n = 20). After exposure, the dentin disks were stained with the fluorescent live/dead dye and evaluated with a confocal scanning electron microscope to calculate the proportion of dead cells. Statistical analysis was done using the Kruskal-Wallis and Mann-Whitney U test (p < 0.05). RESULTS: The maximum proportion of dead cells were seen in the groups treated with the combination of 1% ALX + 5.25% NaOCl (94.89%) and in the control group 5.25% NaOCl (93.14%). The proportion of dead cells presented in the 1% ALX group (51.79%) and negative control group saline (15.10%) were comparatively less. CONCLUSION: The antibacterial efficiency of a combination of 1% ALX and 5.25% NaOCl was more effective when compared with 1% ALX alone. CLINICAL SIGNIFICANCE: Alexidine at 1% could be used as an alternative endodontic irrigant to chlorhexidine, as alexidine does not form any toxic precipitates with sodium hypochlorite. The disinfection regimen comprising a combination of 1% ALX and 5.25% NaOCl is effective in eliminating E. faecalis biofilms.