The influence of new immediate tissue level abutment on crestal bone stability of subcrestally placed implants: A 1‐year randomized controlled clinical trial

Abstract

Background The relation between implant abutment disconnection (AD) and increased crestal bone loss is still debated. Purpose To compare bone changes below implant‐abutment junction of subcrestally placed implants between: (1) implant level restorations, that underwent four ADs and (2) implants with immediate tissue level abutment with no AD, 1 month (T2) and 1‐year (T3) after final restoration delivery. Materials and methods Sixty‐four patients received 64 bone level implants with platform‐switching and conical connection in edentulous sites of posterior mandible and maxilla. All implants were placed 1.5 mm subcrestally and distributed among: (1) control group, that received a regular healing abutment and (2) test group with immediate tissue level (ITL) abutment, which was torqued to implants during surgery, transforming bone level implant to tissue level type. After 2–3 months of healing and a 1‐month temporization, final zirconia‐based screw‐retained crowns were delivered to both groups. Crestal bone levels were calculated after final crown delivery (T2); after 1‐year follow‐up (T3) and compared using Mann–Whitney U test (p ≤ .05). Results Early bone loss of the test and control groups was 0.14 ± 0.27 mm and 0.64 ± 0.64 mm, respectively; the 0.5 mm difference was statistically significant (p = .0001). Late bone loss was 0.06 ± 0.16 mm and 0.21 ± 0.56 mm for the test and control group, respectively; the 0.15 mm difference between the groups was no more statistically significant (p = .22). Both groups displayed bone gain, 0.08 and 0.43 mm, respectively, and the overall crestal bone loss was reduced. Conclusions Immediate tissue level abutments can significantly reduce early bone loss when measured 1 month after final prosthesis delivery, however, after 1‐year follow‐up, difference between the groups was no more statistically significant.

Covariates Relating to Implant Failure and Marginal Bone Loss of a Novel Triangular Neck-Implant Placed by Post-Graduate Students: A 1-Year Prospective Cohort Study

“…The success and survival rates of the 120 V3 implants were 97.5% and 96.7%, respectively; they were similar to the ones obtained by experimented university teams with the same implant [3,4,6,8,12]. They are also comparable to the survival features reported otherwise in the literature with other implant systems [16][17][18]21].…”

“…Micro- and macro-features of implant design include a large range of variables; among them are the geometry and surface of the implant body and its neck [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Several papers have documented the implant neck as a critical factor involved in preservation of the marginal peri-implant bone [ 1 , 3 , 4 , 10 , 11 ].…”

“…Micro- and macro-features of implant design include a large range of variables; among them are the geometry and surface of the implant body and its neck [ 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. Several papers have documented the implant neck as a critical factor involved in preservation of the marginal peri-implant bone [ 1 , 3 , 4 , 10 , 11 ]. To date, the most common implant collar design is the conventional circular one [ 1 , 10 ]; recently, however, a new conical triangular-neck design with three flat and one conical connection surfaces has been made available on the implant market (V3, MIS Implant Technologies, Bar Lev Industrial Park, Israel).…”

“…This shape has been implemented with several objectives in mind. One was to reduce the stresses and strains that are exerted at the cortical bone during implant seating [ 12 ]; the second was to offer added room at the implant neck for thickening the buccal cortical bone lamella [ 4 , 5 , 6 ] under the motto less titanium, more bone, and third to speed-up the neoformation of the crestal bone [ 13 ]. When the implant is seated, the triangular neck design provides a space between the implant collar and the surrounding bone to be filled with blood; it eventually forms a blood clot, which later turns into bone [ 2 , 3 , 4 , 6 , 7 , 8 , 9 ].…”

“…All these above addressed issues are cardinal to prevent complications and reduce the occurrence of aesthetic and biological failures [ 3 ], but documentation of this novel triangular neck shape has been limited so far and was provided by experimented clinicians only [ 3 , 4 , 6 , 8 , 12 ]. Therefore, the purpose of this prospective cohort study was to evaluate, at the 1-year follow-up, the success and survival rates as well as the marginal bone loss (MBL) of the novel V3 triangular-neck implant design when placed and rehabilitated by young inexperienced post-graduate students.…”