Smoke and mirrors - does smoking cause discolouration of composite restorations?

data sourcesSearches were carried out across PubMed, Embase, Scopus and Web of Science for studies published until 28th March 2022. STUDY SELECTION: In vitro studies assessing colour stability of resin-based composites (RBCs) exposed to conventional cigarette smoke (CS), tobacco heating systems (THS) or electronic nicotine delivery systems (ENDS) were considered. Included studies used a spectrophotometer or colorimeter for assessment of discolouration and measured discolouration using CIELAB or CIEDE2000 colour difference formulas. Literature not published in English was excluded. DATA EXTRACTION AND SYNTHESIS: Data was extracted from thirteen studies which met the inclusion criteria. A data collection form was used to collate the extracted information on sample shape, sample diameter, sample thickness, time elapsed before smoke exposure, smoke exposure protocol, colour measurement device, sample finishing method, brushing simulation and whether exposure was to CS, THS or ENDS.

resultsAll 13 included studies analysed CS, four studies analysed ENDS and two studies analysed THS. A high level of variability was identified between the studies in relation to smoke exposure protocol. CS caused the highest level of discolouration of RBCs.

conclusionsThis systematic review of in vitro studies found CS caused irreversible RBC discolouration. ENDS and THS caused less colour change, which could be reversed with repolishing or bleaching procedures, although evidence was limited. Further research is required to consider the long-term effect of CS, ENDS and THS on discolouration of RBCs.