Variability in Tooth Color Selection by Different Spectrophotometers: A Systematic Review

The objective of this study is to evaluate the variability in the precision and reliability of tooth color selection among different spectrophotometers.

A search was performed in the following databases: MEDLINE (PubMed), Google Scholar, Scopus, and Web of Science. A manual search was also performed based on the reference lists of the relevant articles. Screening, data extraction, and quality assessment were performed independently and in duplicate.

In the search strategy, medical subject heading (MeSH) words were used in PubMed, and free terms were used for the titles and abstracts of each article. Each keyword was separated by the Boolean operator OR to later be combined with the Boolean operator AND. All three authors were independently involved in study selection based on the inclusion criteria, data extraction, and bias assessment. The assessment of the risk of bias in the In vivo studies was based on the parameters assigned by the Newcastle–Ottawa tool, and the risk of bias in the in vitro studies was categorized by applying the modified ARRIVE and CONSORT criteria. There was great heterogeneity in the experimental design of the articles that were included: however, no article mentioned or adhered to the indications given by the ISO_TR_28642_2016 standard for color measurement. Six studies were included, two studies provided data on the precision and repeatability of the spectrophotometers, three provided data on repeatability, and one provided data on reliability.

The selection process using the PRISMA flow chart. The search yielded 714 studies. Of these, 88 duplicates were excluded. A total of 579 studies were excluded because their titles and abstracts did not meet the eligibility criteria. The full texts of the other 47 studies were examined, which led to the exclusion of 39 articles that did not meet the inclusion criteria. Two of the remaining eight articles were excluded after applying the modified ARRIVE and CONSORT criteria and the Newcastle–Ottawa criteria. Of the six studies included in the systematic review, two examined the precision and repeatability of the spectrophotometers, three examined repeatability, and one examined reliability.

The SpectroShade Micro and VITA Easyshade show better variability in terms of precision, but they have no significant advantages in reliability.

The protocol was registered with PROSPERO (the international prospective register of systematic reviews) under number CRD42021268853.