The Influence of Restorative Procedures on Esthetic Outcomes in Implant Dentistry: A Systematic Review

Purpose: The objectives of this review were to (1) identify if prosthodontic parameters influence the esthetic outcome of implant-supported restorations and (2) make clinically relevant recommendations based upon the findings. Materials and Methods: Electronic and manual searches of dental literature were performed to collect information on esthetic outcomes based on objective criteria. The prosthodontic parameters included optimal three-dimensional implant position, the utilization of provisional restorations, the timing of provisional restoration with regard to implant placement, the choice of prosthodontic platform size and form, the abutment and definitive restoration material, and the mode of prosthesis retention. Regions including maxillary and mandibular anterior teeth and premolars were considered. All levels of evidence, including case studies, were accepted. Results: From 472 titles, 152 full-text articles were evaluated and 58 records included for data extraction (15 randomized controlled trials, 6 cohort studies, and 37 case series studies). Considerable heterogeneity in study design was found. A meta-analysis of controlled studies was not possible. It was consistently reported that facial malpositioning of implants increases the likelihood of mucosal recession. No studies directly compared esthetic outcomes associated with the use or non-use of provisional restorations. The literature contains a greater number of case series studies evaluating esthetic outcomes for protocols including, rather than excluding, provisional restorations. It is not possible to identify any significant variation in esthetic outcomes based on the character of the abutment platform from the current literature. Based on the findings, no significant difference can be established between all-ceramic and metal-ceramic prostheses with regard to esthetic indices over short observation periods. No firm conclusions relating esthetic benefits for cement in comparison to screw retention can be identified. Conclusions: There is a need for RCTs comparing accepted procedures in routine practice. The utilization of provisional restorations remains strongly recommended in order to trial the planned definitive restoration, to facilitate maturation of healing tissues and for patient convenience. Implant positioning according to the planned prosthesis remains a requirement to achieve a long-lasting esthetic outcome. The majority of studies reported on single-tooth replacement, and many of the outcomes may not be relevant or applicable to the large number of esthetic indications involving more than one tooth. Keywords: abutment material, final restoration material, implant position, implant restoration mode of retention, implant-supported provisional restoration, restorative implant platform size and form, timing of provisional restoration