Efficacy of antimicrobial photodynamic therapy (aPDT) in reducing cariogenic bacteria in primary deciduous dentine

The aim is to systematically review the efficacy of aPDT in minimizing cariogenic bacteria in primary dentine when compared to tooth preparation and endodontic debridement.

The focused question was: Is aPDT (intervention) effective in minimizing the cariogenic bacteria (outcome) in deciduous dentine (participants) after caries removal when compared to before aPDT or mechanical caries removal alone (controls). The keywords that were used were: 'antimicrobial photodynamic therapy', 'dentine', 'primary teeth' and 'deciduous teeth' in different combinations. Following the exclusion of the irrelevant studies, eight (seven clinical studies and one in vitro study) studies were included in the review. The data from each study was extracted and the quality of each article was assessed.

In four out of the eight studies, aPDT with methylene blue or toluidine blue had improved the efficacy of microbial reduction in deciduous dentine when compared to conventional root canal treatment or caries removal. In four studies, no significant improvement in microbial reduction was observed following aPDT compared to caries removal or endodontic debridement without aPDT. Four studies received an overall quality grading of 'medium', three studies were assessed as having a 'low' quality and only one study received an overall grading of 'high' quality.

Within the limitations of this review, aPDT may improve the anti-bacterial efficacy of restorative and endodontic procedures in deciduous teeth. However, due to lack of long-term clinical trials and robust study designs, the efficacy of aPDT in minimizing cariogenic bacteria in deciduous dentine is debatable.