Does flapless immediate implant placement lead to significant preservation of buccal bone compared to flap surgical protocol?

Abstract

Design

A systematic review and meta-analysis of randomized clinical trials.

Data sources

The electronic search included Pubmed, Web of Science, Embase, and Cochrane databases up to June 2022. Cross-referencing, searching for gray literature at (www.clinicaltrials.gov), and hand searching of seven relevant journals were also performed.

Selection criteria

Inclusion criteria consisted of: randomized clinical trials (RCTs) published in English comparing flapless to flap surgery for IIP using single titanium implants in the esthetic zone of healthy ≥18 years old patients. Prospective and retrospective case series, cross-sectional studies, letters to editors and reviews were excluded. The key study factor was to assess the impact of the surgical approach (flap versus flapless surgery) on buccal hard and soft tissue changes after single immediate implants for the anterior teeth in healthy adult patients. The primary outcome was horizontal buccal bone change (HBBC), measured by CBCT. Secondary outcomes were implant survival, vertical buccal bone change, postoperative pain, and clinical and esthetic parameters.

Data extraction and synthesis

Two independent reviewers conducted both electronic and manual searches for eligible clinical studies. The evaluation was carried out at the title level followed by the abstract level, and the full texts of the qualified articles were then examined. Any disagreements were resolved by discussion with a third reviewer. Quality assessment of the included RCTs was conducted by two additional reviewers who were not part in the search process using the revised Cochrane risk-of-bias tool for randomized trials (RoB 2). A meta-analysis was conducted on outcome variables that were documented in three or more articles.

Results

Five RCTs fully met the selection criteria for the final qualitative analysis comprising data of 140 patients who received 140 single immediate implants (flapless: 68; flap:72) with a mean age ranging from 30 to 67 years. Follow-up extended for 6–12 months. Two RCTs showed an overall low risk of bias, whereas the other three RCTs had an overall high risk, basically due to using inappropriate methods of outcome measurements. Meta-analysis included three RCTs and revealed a mean difference of 0.48 mm (95% CI [0.13,0.84], p = 0.007) in HBBC between surgical approaches, favoring flapless surgery. Heterogeneity among the studies was low (I² = 29%; p = 0.250). For implant survival, however, meta-analysis failed to find a significant difference among the groups (RR 1.00, 95% CI [0.93, 1.07], p = 0.920). Due to limited data, meta-analyses could not be conducted for other secondary outcomes. Available studies consistently showed a favorable effect of flapless surgery in terms of vertical buccal bone change and pain, while only one study assessed the vertical midfacial soft tissue change, and no data were reported on esthetic outcomes.

Conclusion

According to CBCT data, flapless IIP resulted in greater preservation of buccal bone as compared to flap IIP. However, the clinical significance of this finding remains uncertain since clinical and esthetic outcomes were insufficiently reported.