The influence of submerged healing abutment or subcrestal implant placement on soft tissue thickness and crestal bone stability. A 2‐year randomized clinical trial

Abstract

PurposeAims of the study were: (a) to register crestal bone loss around 1.5 mm subcrestally placed implants and epicrestally placed implants with soft tissue tenting technique, (b) to record bone remodeling in subcrestal group, and (c) to determine the increase of vertical soft tissues after tenting.Materials and methodsThirty‐two patients with vertically thin tissues of 2 mm or less received 40 submerged bone level platform‐switched implants, divided into two groups—(a) 1.5 mm subcrestally placed implants and (b) epicrestally placed implants with soft tissue tenting over 2 mm healing abutments. At the second stage surgery, implants received 4 mm healing abutments, soft tissue thickness was measured in epicrestal group, and later implants were restored with zirconia‐based screw‐retained single restorations. Radiological images were taken at the second stage surgery, restoration delivery and after 2 years of follow‐up. Bone loss was calculated as a distance between implant neck and first radiographically visible bone‐to‐implant contact. Bone remodeling was calculated as a distance between the bone crest and implant neck. Mann‐Whitney U test was used for statistical analysis, significance set to 0.05.ResultsAfter 2 years of follow‐up, Group 1 (subcrestal) had 0.18 ± 0.32 mm of bone loss, Group 2 (epicrestal with 2 mm healing abutment) had 0.51 ± 0.4 mm of bone loss, with statistically significant difference (P = .001). Bone remodeling in Group 1 (subcrestal) was 1.17 ± 0.51 mm. Vertical tissue thickness in epicrestal group before the intervention was 1.85 ± 0.26 and 3.65 ± 0.41 mm after the use of 2 mm healing abutment, with a statistical difference (P = .005).ConclusionSubcrestal implant placement can significantly reduce crestal bone loss, compared to vertical soft tissue thickening by tenting of epicrestally placed implants, although soft tissue tenting can significantly increase soft tissue thickness.

Decompression technique — A modified approach for lateral alveolar ridge augmentation: A case report

“…It can be summarized that, during the one-stage approach while using a 2-mm healing abutment, we can achieve subcrestal implant position and augment STH. 28,29 Furthermore, during the second surgery of implant disclosure, there is no need to reflect a full-thickness flap, especially when it is generally accepted that elevation of a periosteal flap is directly correlated with the risk of crestal bone loss. 30,31 A short incision is sufficient to replace the 2 mm healing abutment with another abutment .…”

“…The use of 2 mm healing abutment shows various advantages in comparison with a cover screw. It can be summarized that, during the one‐stage approach while using a 2‐mm healing abutment, we can achieve subcrestal implant position and augment STH 28,29 …”

The Long-Term Effect of Adapting the Vertical Position of Implants on Peri-Implant Health: A 5-Year Intra-Subject Comparison in the Edentulous Mandible Including Oral Health-Related Quality of Life

“…A recent clinical trial tried to overcome the initial bone remodeling due to biologic width re-establishment by using a soft tissue tenting technique [ 23 ]. These implants were placed equicrestal with soft tissue tenting over 2 mm healing abutments.…”

Five Degree Internal Conical Connection and Marginal Bone Stability around Subcrestal Implants: A Retrospective Analysis

“…On the other hand, studies evaluating bone remodeling, rather than marginal bone loss, showed that implants placed subcrestally observed a greater extent of bone resorption during the first 12 month after prosthetic delivery [ 24 , 38 ]. Moreover, some clinical trials suggest that, in presence of thin supracrestal tissue, a subcrestal implant placement may reduce the probability for the implant to become exposed over time [ 39 , 40 , 41 ]. From the findings of the present study, it can be observed that at t 1 , the implant neck was located coronal to the marginal bone level only in very few cases.…”