Temperature Analysis during Bonding of Brackets Using LED or Halogen Light Base Units

Antimicrobial photodynamic therapy in endodontic reintervention: A systematic review and meta-analysis

BACKGROUND

To evaluate the effectiveness of the use of antimicrobial photodynamic therapy (aPDT) in root canals disinfection in cases of endodontic retreatments.

METHODS

This Systematic Review was registered in PROSPERO (CRD42021260013) and followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). Searches were performed in the electronic databases PubMeb, Scopus, Web of Science, Embase, Web of Science, Clinical Trials and Cochrane Library. Methodological quality and risk of bias were assessed by the Cochrane Risk of Bias tool for randomized clinical trials (RCT) and by the Newcastle-Ottawa (NOS) qualifier for non-RCT (prospective) studies. Meta-analysis was performed using R software, version 3.6.3 with the "META" package assistant by the RStudio platform. The odds ratio (OR) measure of effect was calculated and the random effect model was applied with a 95% confidence interval, and heterogeneity tested by the I2 index. The certainty of evidence was rated using GRADE.

RESULTS

Regarding the 1513 studies screened, 10 met the eligibility criteria and were included, and 8 used in the quantitative synthesis. Meta-analysis showed that all of studies data presented a significant difference before and after of antimicrobial photodynamic therapy in the microbial load reduction in secondary endondontic infections (OR 0.15 [0.07; 0.32], p < 0.0001). Overall, the studies had a low risk of bias and, the analysis of evidence by GRADE assessment was rated as moderate.

CONCLUSION

It is suggested that aPDT is a beneficial and promising tool, showing efficacy in reducing the microbial load in cases of endodontic retreatment.

Antimicrobial photodynamic therapy against metronidazole-resistant dental plaque bactéria

The antimicrobial photodynamic therapy (aPDT) has stood out as an alternative and promising method of disinfection and has been exploited for the treatment of oral bacteria. In this study, we evaluate in vitro the action of aPDT, mediated by methylene blue, chlorin-e6, and curcumin against clinical subgingival plaques that were resistant to metronidazole. The sensitivity profile of the samples to metronidazole was analyzed by the agar dilution method. Cell viability in the planktonic and biofilm phase was assessed by CFU / mL. The composition of the biofilm was evaluated by the checkboard DNA-DNA Hibrydization technique. Photosensitizers internalization was qualitatively assessed by confocal fluorescence microscopy (CLSM). The aPDT mediated by the three photosensitizers tested was able to reduce the totality of the planktonic microbial load and partially reduce the biofilm samples. The analysis performed by CLSM showed that the photosensitizers used in the application of aPDT were able to permeate the interior of the biofilm. The aPDT has been shown to be useful in a supportive and effective approach to the treatment of periodontal disease.

Rapid Antibiofilm Effect of Ag/ZnO Nanocomposites Assisted by Dental LED Curing Light against Facultative Anaerobic Oral Pathogen Streptococcus mutans

The integration of nanomaterials with clinical therapeutic instruments is a promising approach to improve the effects of nanomaterials. We reported an efficient synergistic antibacterial strategy formed through the combination of Ag/ZnO nanocomposites with a light-emitting diode (LED) curing light, which is a commonly used small instrument in dental clinics. The as-designed integration depicted a significantly enhanced bactericidal effect on facultative anaerobic oral pathogen Streptococcus mutans (S. mutans) both in planktonic and biofilm phases over a very short irradiation time (≤5 min). Further study showed that the combination of LED and Ag/ZnO nanocomposites induced more ·OH and ·O₂^- generation, which is responsible for the enhanced antibacterial activity. Moreover, this combination could destroy S. mutans biofilm by killing the bacteria embedded within biofilm, inhibiting exopolysaccharide production and down-regulating the biofilm-related gene expression. Therefore, it is proposed that this combination could be applied in dental clinics to realize dental caries prevention and dental restoration simultaneously.

Influence of various polishing methods on pulp temperature : an in vitro study

OBJECTIVE

After orthodontic debonding, adhesive removal can lead to rises in pulp temperature, causing histological changes or pulp necrosis. The objective of this study was to measure increases in pulp temperature during adhesive removal using different instruments and various cooling procedures.

MATERIALS AND METHODS

A thermoelement was introduced into the pulp chamber of 10 human incisors. The teeth were immersed in a 36°C water bath up to the cementoenamel junction. Two carbide burs, one polishing disk and two rubber points were used for polishing. All measurements were taken over a 10 s period by a single investigator, under slight pressure and with constant motion. Three cooling procedures were examined: no cooling, air cooling and water cooling. Pulp temperatures were measured before polishing and after 10 s of polishing.

RESULTS

Without cooling, the two rubber points revealed clinically relevant temperature increases of 6.1°C and 12.4°C. Cooling with air and with water reduced pulp temperature in conjunction with all polishing methods. Air cooling was most efficient, except in combination with the polishing disk.

CONCLUSION

Under these study conditions, carbide burs and polishing disks can be used safely and without risk to the pulp, even without cooling. On the other hand, rubber points cause a marked increase in pulp temperature when used without cooling.