Published online Mar 26, 2020. doi: 10.12998/wjcc.v8.i6.1087
Peer-review started: October 21, 2019
First decision: November 11, 2019
Revised: November 13, 2019
Accepted: December 6, 2019
Article in press: December 6, 2019
Published online: March 26, 2020
The conventional implant approach involves flap elevation, which may result in increased soft tissue and bone loss and postoperative morbidity. The flapless surgical technique, aided by three-dimensional medical imaging equipment, is regarded as a possible alternative to the conventional approach to alleviate the above issues. Several studies have been performed regarding the role of flapless implant surgery. However, the results are inconsistent and there is no robust synthesis of long-term evidence to better inform surgeons regarding which type of surgical technique is more beneficial to the long-term prognosis of patients in need of implant insertion.
To compare the long-term clinical performance after flapless implant surgery to that after the conventional approach with flap elevation.
PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and grey literature databases were searched from inception to 23 September 2019. Randomised controlled trials (RCTs) and cohort studies comparing the long-term clinical performance after flapless implant surgery to that after the conventional approach over a follow-up of three years or more were included. Meta-analyses were conducted to estimate the odds ratios (ORs) or mean differences (MDs) and their 95% confidence intervals (CIs) between the long-term implant survival rate, marginal bone loss, and complication rate of the flapless and conventional groups. Subgroup analyses were carried out to account for the possible effects of the guided or free-hand method during flapless surgery.
Ten articles, including four RCTs and six cohort studies, satisfied the eligibility criteria and nine of them were included in the meta-analysis. There was no significant difference between the long-term implant survival rate [OR = 1.30, 95%CI (0.37, 4.54), P = 0.68], marginal bone loss [MD = 0.01, 95%CI (-0.42, 0.44), P = 0.97], and complication rate [OR = 1.44, 95%CI (0.77, 2.68), P = 0.25] after flapless implant surgery and the conventional approach. Moreover, subgroup analyses revealed that there was no statistically significant difference between the implant survival rate [guided: OR = 1.52, 95%CI (0.19, 12.35), P = 0.70]; free-hand: n = 1, could not be estimated), marginal bone loss [guided: MD = 0.22, 95%CI (-0.14, 0.59), P = 0.23; free-hand: MD = -0.27, 95%CI (-1.10, 0.57), P = 0.53], or complication rate [guided: OR = 1.16, 95%CI (0.52, 2.63), P = 0.71; free-hand: OR = 1.75, 95%CI (0.66, 4.63), P = 0.26] in the flapless and conventional groups either with use of the surgical guide or by the free-hand method.
The flapless surgery and conventional approach had comparable clinical performance over three years or more. The guided or free-hand technique does not significantly affect the long-term outcomes of flapless surgery.
Core tip: This is the first systematic review and meta-analysis to compare the long-term clinical performance after flapless implant surgery to that of the conventional approach with flap elevation over a follow-up of three years or more. Interestingly, we found that the flapless implant surgery and conventional approach had comparable implant survival rates, marginal bone loss, and complication rates over the follow-up period. Moreover, guided or free-hand implant insertion does not affect the long-term effects of flapless surgery. Thus, the flapless technique can be considered a promising alternative to the conventional implant approach without significantly compromising the long-term outcomes of implant treatment.