Meta-Analysis
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Mar 26, 2020; 8(6): 1087-1103
Published online Mar 26, 2020. doi: 10.12998/wjcc.v8.i6.1087
Long-term clinical performance of flapless implant surgery compared to the conventional approach with flap elevation: A systematic review and meta-analysis
He Cai, Xing Liang, Dong-Yuan Sun, Jun-Yu Chen
He Cai, Xing Liang, Dong-Yuan Sun, Jun-Yu Chen, Department of Prosthodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan Province, China
He Cai, Botnar Research Centre, University of Oxford, Windmill Road, Oxford OX3 7LD, United Kingdom
Jun-Yu Chen, Kennedy Institute of Rheumatology, University of Oxford, Roosevelt Drive, Oxford OX3 7FY, United Kingdom
Author contributions: Cai H made a substantial contribution to study planning, study screening, data extraction, data analysis and interpretation, drafting and revising the manuscript; Liang X provided methodological advice for this study and contributed to study planning, data acquisition, analysis, interpretation, and revising the manuscript; Sun DY contributed to data interpretation, drafting and revising the manuscript; Chen JY made a substantial contribution to conception of the study, study planning, acquisition and analysis of data, drafting and revising the manuscript; All authors read and approved the final version of the manuscript.
Supported by the Graduate Student's Research and Innovation Fund of Sichuan University, No. 2018YJSY108; the China Postdoctoral Science Foundation Funded Project, No. 2018M640931; the Science and Technology Key Research and Development Program of Sichuan Province, No. 2019YFS0142; the National Natural Science Foundation of China, No. 81901060.
Conflict-of-interest statement: The authors deny any conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared, revised, and checked according to the PRISMA 2009 Checklist. The PRISMA 2009 Checklist has been submitted with the manuscript.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Jun-Yu Chen, MD, PhD, Lecturer, Department of Prosthodontics, State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, No. 14, Section 3, South Renmin Road, Chengdu 610041, Sichuan Province, China. junyuchen@scu.edu.cn
Received: October 21, 2019
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
Processing time: 156 Days and 13.5 Hours
Abstract
BACKGROUND

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.

AIM

To compare the long-term clinical performance after flapless implant surgery to that after the conventional approach with flap elevation.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Keywords: Flapless implant surgery; Dental implantation; Minimally invasive surgical procedures; Computer-assisted surgery; Cone-beam computed tomography; Implant survival rate; Marginal bone loss; Complication rate

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.