Effect of Ti-Base Abutment Gingival Height on Maintenance of Crestal Bone in Thick Biotype Patients: A Randomized Clinical Trial with 1-Year Follow-up.

PURPOSE: To determine the effect of 0.7- and 2.4-mm transmucosal abutment height titanium bases on the crestal bone stability and peri-implant soft tissue condition of bone-level implants with platform switching in patients with vertically thick soft tissues. MATERIALS AND METHODS: Sixty bone-level platform-switched implants were placed in the molar and premolar regions of both arches in 60 patients. All epicrestally inserted nonsubmerged implants had a 4.1-mm diameter and, after osteointegration, were randomly allocated into two groups: (1) the short group, with a titanium base of 0.7-mm transmucosal abutment height, and (2) the high group with a 2.4-mm height. Monolithic zirconia restorations were fabricated for all implants. Parallel intraoral radiographs were obtained after the delivery of restorations (T1) and after 1 year (T2). Crestal bone levels and peri-implant soft tissue conditions were calculated for each implant. The significance level was set at α = .05. RESULTS: After 1 year, 55 patients were evaluated, with a mean bone loss of 0.6 ± 0.51 mm (median: 0.71, range: 0 to 2.09 mm) in the short group (23 patients) and 0.45 ± 0.59 mm (median: 0.65, range: 0 to 2.12 mm) in the high group (22 patients), showing no significant difference between groups (P = .168). A significant increase in marginal bone height was noted between the T1 and T2 time points in the short and high (P = .029 and .001, respectively) groups. The peri-implant soft tissue health parameters did not show statistically significant differences. CONCLUSION: Crestal bone stability after 1 year of follow-up around epicrestally placed platform-switched implants is not influenced by transmucosal abutment height, if the vertical soft tissue thickness is ≥ 3 mm.

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

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.

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

PURPOSE: Aims 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 METHODS: Thirty-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. RESULTS: After 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). CONCLUSION: Subcrestal 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.

Early crestal bone loss: Is it really loss?

Bone remineralization around dental implants might be possible after early crestal bone loss.

Bone Remineralization around Dental Implants following Conservative Treatment after Peri-Implantitis.

The aim of this case report is to show that bone remineralization around dental implants with a history of peri-implantitis is possible after irritant factors are removed and only conservative treatment is performed. Patient came to the clinic after three years of dental implant placement complaining about swelling, sensitivity and gingiva color changes at the posterior part of the maxilla. During radiographic and intraoral examinations peri-implantitis of the #24 implant site was diagnosed. The surgical treatment method was rejected and performed conservative treatment instead. The outcome is promising; periapical radiographs three months later showed bone remineralization as well as stable bone after 10 years. A key clinical message: Bone remineralization around dental implants with a history of peri-implantitis is possible after irritant factors are removed and conservative treatment performed.

Influence of titanium base, lithium disilicate restoration and vertical soft tissue thickness on bone stability around triangular-shaped implants: A prospective clinical trial.

OBJECTIVE: To evaluate how vertical mucosal tissue thickness affects crestal bone stability around triangular-shaped bone-level implants, restored with low profile titanium bases and monolithic lithium disilicate restorations. MATERIAL AND METHODS: Fifty-five bone-level implants of 4.3 mm diameter were evaluated in 55 patients (22 males and 34 females, mean age 48.3 ± 3.4 years) in prospective cohort study. According to vertical mucosal thickness, patients were assigned into three groups: 1 (thin, 2 mm or less), 2 (medium, 2.5 mm) and 3 (thick, 3 mm and more). Implants were placed in posterior mandible and maxilla in one-stage approach and, after integration, were restored with single screw-retained monolithic lithium disilicate crowns, using low gingival profile titanium bases. Radiographic examination was performed after implant placement and after 1-year follow-up. Crestal bone loss was registered mesially and distally, and mean value was calculated. One-way ANOVA and Tukey's HSD tests were applied; significance was set to 0.05. RESULTS: Mean vertical tissue thickness in 1 group was 1.76 ± 0.26 mm, 2 group-2.5 mm and 3.91 ± 0.59 mm in group 3, with statistically significant difference between all groups (p < 0.001). After 1-year follow-up, implants in group 1 (thin) had 1.25 ± 0.8 mm bone loss. Implants in group 2 (medium) had 0.98 ± 0.06, while implants in group 3 (thick) lost 0.43 ± 0.37 mm of crestal bone. Tukey's HSD test showed that differences between 1/3 and 2/3 were statistically significant (p < 0.001 and p = 0.0014, respectively), while between 1 and 2 was not significant (p = 0.310). CONCLUSIONS: Significantly less bone loss occurs around triangular-shaped bone-level implants in thick mucosal tissues (≥3 mm), compared to medium or thin tissue biotype. Crestal bone loss did not differ between medium and thin tissues.

Radiological comparison of laser-microtextured and platform-switched implants in thin mucosal biotype.

OBJECTIVE: To compare how laser-microtextured implants and implants with platform switching maintain crestal bone stability in thin peri-implant tissues. MATERIAL AND METHODS: Thirty laser-microtextured implants of 4.6 mm diameter (Tapered Internal Laser-Lok, BioHorizons, Birmingham, AL, USA; Group 1) and 30 implants with platform switching of 5/4 mm diameter (Certain Prevail; Biomet/3i, Palm Beach Gardens, FL, USA; Group 2) were placed in 30 patients (12 males and 18 females, mean age 42.3 ± 2.4) with thin mucosal tissues (≤2 mm). Implants were placed in posterior mandible in one-stage approach and after integration were restored with screw-retained metal-ceramic restorations. Radiographic examination was performed after implant placement, 2 months after healing, at prosthetic restoration delivery and after 1-year follow-up. Mean crestal bone loss was calculated, Mann-Whitney U-test was applied, and significance was set to 0.05. RESULTS: After 2 months of healing, the crestal bone loss was 0.71 ± 0.25 mm SD (range, 0.25-1.6 mm) and 1.02 ± 0.25 mm SD (range, 0.6-1.55 mm) in groups 1 and 2, respectively (P = 0.001). At restorations' delivery, the crestal bone loss was 1.10 ± 0.30 mm SD (range, 0.65-1.85 mm) and 1.37 ± 0.27 mm SD (range, 0.90-1.80 mm) in groups 1 and 2, respectively (P = 0.001). After 1-year follow-up, the crestal bone loss was 1.41 ± 0.42 mm SD (range, +0.1-2.30 mm) and 1.43 ± 0.23 mm SD (range, 1-1.80 mm) in groups 1 and 2, respectively (P = 0.976). CONCLUSIONS: Laser-microtexturing of implant collar or platform-switched implant/abutment connection did not eliminate crestal bone loss, if at the time of implant placement vertical soft tissue thickness was ≤2 mm. However, laser-microtextured implants may present less proximal bone loss than platform-switching implants in the period before implant loading.