Clinical and ex-vivo effect of LASERs on prevention of early-enamel caries: systematic review & meta-analyses

Abstract

To investigate the in vivo and in situ effect of different types of lasers in prevention of enamel demineralization in high caries risk cases (around orthodontic brackets, around restoration and in caries susceptible pits and fissures). PubMed was searched using the following keyword sequence; (Laser therapy OR laser irradiation OR laser application) AND (enamel caries prevention OR enamel demineralization OR enamel remineralization OR early enamel caries OR early-enamel caries OR enamel resistance OR enamel decalcification OR white spot lesions WSLs OR incipient lesion OR enamel decay OR enamel Dissolution OR enamel microhardness) AND (clinical trial OR Randomized clinical trial OR In situ study). The latest literature search was ended by "30 January 2023". PubMed was used as a primary data base for study selection. Scopus, EBSCO, and Google scholar are checked in our study after results of systematic search on PubMed. Only duplicates were found. Two meta-analyses were carried out. The first, clinical meta-analysis on incidence of white spot lesions (WSLs) following CO2 laser irradiation of enamel. The second meta-analysis on ex-vivo/in situ effect of CO2 laser on microhardness of enamel. In each meta-analysis three studies were included. Risk of bias was assessed. The search identified eight studies (four ex-vivo and four clinical trials). Regarding the clinical meta-analysis, the overall standardized mean difference was 0.21 [ 95% confidence interval (CI): 0.15-0.30, p < 0.00001]. This indicates that the incidence of new WSLs in patients who received low power CO₂ laser treatment was highly significantly lower than placebo groups. The heterogeneity was considerable (I² = 71%). In the second meta-analysis, the overall standardized mean difference was 49.55 [ 95% confidence interval (CI): 37.74, 61.37, p < 0.00001]. This indicates that microhardness of enamel receiving low power (0.4-5 W) CO₂ laser irradiation is highly significantly lower than control untreated enamel. The heterogeneity was substantial (I² = 48%). Within the limitations of this study, Low level laser therapy concept with CO2 laser seems to be effective in preventing enamel caries.Prospero registration number: CRD42023437379.

Keywords: Caries detection; Caries diagnosis; Caries prevention; Demineralization; Enamel; Lasers; Preventive dentistry; Remineralization.

Fig. 1

PRISMA flow diagram illustrating the literature search protocol PRISMA – preferred reporting items for systematic reviews and meta-analysis

Fig. 2

Forest plot of meta-analysis on incidence of enamel carious lesions in patients received Low Level Laser Therapy (0.5–2 W) utilizing CO₂ laser compared to placebo. * Repeated study names are different subgroups (incidence of new lesions in successive follow periods within the study; 3 months to 18 months)

Fig. 3

Funnel plot

Fig. 4

Forest plot of meta-analysis comparing microhardness of enamel received CO₂ laser treatment compared to control untreated enamel

Fig. 5

a Risk of bias graph. b Risk of bias summary