OBJECTIVE: To compare immediate implant placement (IIP) with early implant placement (EIP) for single tooth replacement in the aesthetic area in terms of aesthetic, clinical, and patient-reported outcomes.
METHODS: Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, Embase, and Cochrane databases as well as a manual search to identify eligible clinical studies up to February 2023. Randomized Controlled Trials (RCTs) comparing IIP with EIP were included for a qualitative and quantitative analysis. The primary outcome was vertical midfacial soft tissue change. Secondary outcomes were horizontal midfacial soft tissue change, vertical papillary change, pink esthetic score (PES), implant survival, buccal bone thickness, marginal bone level change, patient discomfort, chair time, and patient satisfaction.
RESULTS: Out of 1185 records, 6 RCTs were selected, reporting on 222 patients who received 222 single implants (IIP: 112 implants in 112 patients; EIP: 110 implants in 110 patients) in the anterior maxilla or mandible. Patients had a mean age ranging from 35.6 to 52.6 years and were followed between 8 and 24 months. Two RCTs showed some concerns, and four showed a high risk of bias. Four studies could be included in a meta-analysis on the primary outcome and three only considered cases with an intact buccal bone wall. Meta-analysis failed to demonstrate a significant difference in terms of vertical midfacial soft tissue change between IIP and EIP (mean difference: 0.31 mm, 95% CI [-0.23; 0.86], p = .260; I2 = 83%, p < .001). No significant differences were found for PES (standardized mean difference: 0.92, 95% CI [-0.23; 2.07], p = .120; I2 = 89%, p < .001), implant survival (RR: 0.98, 95% CI [0.93, 1.03], p = .480; I2 = 0%, p = .980), and marginal bone level change (mean difference: 0.03 mm, 95% CI [-0.12, 0.17], p = .700; I2 = 0%, p = .470). Insufficient data were available for meta-analyses of other secondary outcomes.
CONCLUSIONS: In low-risk patients with an intact buccal bone wall, there seems to be no difference between IIP and EIP in terms of aesthetic and clinical outcomes. The strength of this conclusion is rated as low since studies showed an unclear or high risk of bias. In addition, state-of-the-art therapy was only delivered in a minority of studies. Future RCTs should also provide data on patient-reported outcomes since these have been underreported.

OBJECTIVE: To compare and report on the performance of implant-supported fixed dental prostheses (iFDPs) fabricated using additive (AM) or subtractive (SM) manufacturing.
METHODS: An electronic search was conducted (Medline, Embase, Cochrane Central, Epistemonikos, clinical trials registries) with a focused PICO question: In partially edentulous patients with missing single (or multiple) teeth undergoing dental implant therapy (P), do AM iFDPs (I) compared to SM iFDPs (C) result in improved clinical performance (O)? Included were studies comparing AM to SM iFDPs (randomized clinical trials, prospective/retrospective clinical studies, case series, in vitro studies).
RESULTS: Of 2\'184 citations, no clinical study met the inclusion criteria, whereas six in vitro studies proved to be eligible. Due to the lack of clinical studies and considerable heterogeneity across the studies, no meta-analysis could be performed. AM iFDPs were made of zirconia and polymers. For SM iFDPs, zirconia, lithium disilicate, resin-modified ceramics and different types of polymer-based materials were used. Performance was evaluated by assessing marginal and internal discrepancies and mechanical properties (fracture loads, bending moments). Three of the included studies examined the marginal and internal discrepancies of interim or definitive iFDPs, while four examined mechanical properties. Based on marginal and internal discrepancies as well as the mechanical properties of AM and SM iFDPs, the studies revealed inconclusive results.
CONCLUSIONS: Despite the development of AM and the comprehensive search, there is very limited data available on the performance of AM iFDPs and their comparison to SM techniques. Therefore, the clinical performance of iFDPs by AM remains to be elucidated.

To assess the impact of mucoperiosteal flap elevation for single immediate implant placement (IIP) on buccal hard and soft tissue changes, and on clinical, aesthetic and patient-reported outcomes.
Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to June 2022. Randomized controlled trials (RCTs) comparing IIP without flap elevation to IIP with flap elevation were included for a qualitative and quantitative analysis. The primary outcome was horizontal buccal bone change. Secondary outcomes were implant survival, vertical buccal bone change, pain, and clinical and aesthetic parameters.
Out of 1029 records, 5 RCTs were selected reporting on 140 patients who received 140 single immediate implants (flapless: 68; flap: 72). Patients had a mean age ranging from 30 to 67 years and were followed between 6 and 12 months. Four RCTs pertained to (nearly) intact alveoli. Risk of bias assessment yielded low risk for two RCTs and high risk for three RCTs. Meta-analysis demonstrated a mean difference of 0.48 mm (95% confidence interval [CI] [0.13, 0.84], p = .007) in horizontal buccal bone change between surgical approaches, favouring flapless surgery. Meta-analysis failed to demonstrate a significant difference in implant survival between the groups (RR 1.00, 95% CI [0.93, 1.07], p = .920). Given the scarcity of data, meta-analyses could not be performed on other secondary outcomes. Available studies were consistent in the direction of the effect favouring flapless surgery for vertical buccal bone change as well as for pain. Clinical and aesthetic parameters were underreported.
Based on CBCT data, flapless surgery resulted in more buccal bone preservation at immediate implants. However, the clinical relevance of this finding is unclear, since clinical and aesthetic outcomes were underreported.

OBJECTIVE: To assess the effect of grafting the gap (SG) between the implant surface and alveolar socket on hard and soft tissue changes following single immediate implant placement (IIP).
METHODS: Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to August 2021. Randomized controlled trials (RCTs) comparing IIP with and without SG were included for a qualitative analysis. Meta-analyses were performed when possible.
RESULTS: Out of 3627 records, 15 RCTs were selected and reported on 577 patients who received 604 single immediate implants (IIP + SG: 298 implants in 292 patients; IIP: 306 implants in 285 patients) with a mean follow-up ranging from 4 to 36 months. Two RCTs showed low risk of bias. Meta-analysis revealed 0.59 mm (95% CI [0.41; 0.78], p < 0.001) or 54% less horizontal buccal bone resorption following IIP + SG when compared to IIP alone. In addition, 0.58 mm (95% CI [0.28; 0.88], p < 0.001) less apical migration of the midfacial soft tissue level was found when immediate implants were installed with SG. A trend towards less distal papillary recession was found (MD 0.60 mm, 95% CI [-0.08; 1.28], p = 0.080) when SG was performed, while mesial papillae appeared not significantly affected by SG. Vertical buccal bone changes were also not significantly affected by SG. Insufficient data were available for meta-analyses on horizontal midfacial soft tissue changes, pink esthetic score, marginal bone level changes, probing depth and bleeding on probing. Based on GRADE guidelines, a moderate recommendation for SG following IIP can be made.
CONCLUSIONS: SG may contribute to horizontal bone preservation and soft tissue stability at the midfacial aspect of immediate implants. Therefore, SG should be considered as an adjunct to IIP in clinical practice.

To assess the effect of connective tissue graft (CTG) in terms of vertical mid-facial soft tissue change when applied at the buccal aspect following single immediate implant placement (IIP).
Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, EMBASE and Cochrane databases as well as a manual search to identify eligible clinical studies up to January 2020. Randomized controlled trials (RCTs) and non-randomized controlled studies (NRSs) comparing IIP with CTG and without CTG over a mean follow-up of at least 12 months were included for a qualitative analysis. Meta-analyses were performed on data provided by RCTs.
Out of 1814 records, 5 RCTs and 3 NRSs reported on 409 (IIP + CTG: 246, IIP: 163) immediately installed implants with a mean follow-up ranging from 12 to 108 months. Only 1 RCT showed low risk of bias. Meta-analysis revealed a significant difference in terms of vertical mid-facial soft tissue change between IIP + CTG and IIP pointing to 0.41 mm (95% CI [0.21; 0.61], p < .001) in favour of soft tissue grafting. This outcome was clinically relevant since the risk for ≥1 mm asymmetry in mid-facial vertical soft tissue level was 12 times (RR 12.10, 95% CI [2.57; 56.91], p = .002) lower following IIP + CTG. Soft tissue grafting also resulted in a trend towards less bleeding on probing (MD 17%, 95% CI [-35%; 1%], p = .06). Meta-analyses did not reveal significant differences in terms of pink aesthetic score, marginal bone level change and probing depth. Results were inconclusive for horizontal mid-facial soft tissue change and papilla height change. Based on GRADE guidelines, a moderate recommendation for the use of a CTG following IIP can be made.
CTG contributes to mid-facial soft tissue stability following IIP. Therefore, CTG should be considered when elevated risk for mid-facial recession is expected in the aesthetic zone (thin gingival biotype, <0.5 mm buccal bone thickness).