The influence of the gingival phenotype on implant survival rate and clinical parameters: a systematic review.

Abstract

Objective: The goal of this systematic review was to verify whether the gingival phenotype (thick or thin) could impact the dental implant survival rate by affecting the marginal bone.

Methods: The search was carried out on PubMed/MedLine, PubMed Central, and B-On databases. The research question was: "Does gingival phenotype positively or negatively influence marginal bone loss around dental implants?" The inclusion criteria were: any clinical trial/study, comparative study, prospective or retrospective articles, systematic review that addressed at least a 1-year follow-up with an assessment of the marginal bone loss (MBL) around dental implants, articles that reported the gingival phenotype (thin or thick) and were published in the last 13 years. The exclusion criteria were narrative or other reviews, letters to the editor, and commentaries. Data extraction included the author's name, year of publication, type of study, sample size, number of implants, method used, and outcomes presented. The extracted data was summarized and presented in the results section. Critical Appraisal tool in JBI Systematic Reviews was used to determine the possibility of bias.

Results: A total of 62 articles were found, but eight articles were relevant to compose this study. After deep evaluation, it was possible to observe the implant success rate for both gingival phenotypes, thin and thick, was greater than 91% within a follow-up of up to 5 years. Therefore, it is unclear whether the thickness of the gingival tissue surrounding the implant can directly influence the marginal bone level. The gingival phenotype may be indirectly involved in the survival rate of dental implants, as it can be a risk factor for peri-implantitis, leading to marginal bone loss beyond what is expected.

Discussion: The thin gingival phenotype is one of the main risk factors for additional bone loss. It is crucial to know how to preserve the healthy condition.

Conclusion: Within the results found, the gingival phenotype is indirectly related to implant survival rate and clinical parameters, which were respectively high and non-conclusive. Therefore, a higher risk of peri-implantitis is suggested when a thin phenotype is present.