Marginal bone loss around bone-level and tissue-level implants: A systematic review and meta-analysis.

PURPOSE: To review the scientific evidence regarding the marginal bone loss around the tissue-level and bone-level implants. METHODS: MEDLINE-PubMed and EMBASE databases were searched for the relevant English articles (up to February 2019) assessing the marginal bone loss (MBL) as the primary outcome. To be selected, studies were supposed to directly mention "tissue-level" and "bone-level" implants or implants with and without a smooth neck. Relevant data were extracted and meta-analysis was performed to evaluate the effect of implant neck design. RESULTS: A total of 19 studies (10 clinical, and 9 RCT studies) were included for qualitative analysis. There was a vast heterogeneity between studies in terms of implant designs and study protocol. Out of 19 articles included, 11 studies reached to a statistically significant difference in MBL between the groups; however, the differences were not found to be clinically relevant. Bone-level implants with platform-switched abutments in most of the cases showed better marginal bone stability compared to tissue-level implants or bone-level implants with matching abutments. Seven RCTs with 12 months follow-up data were selected for meta-analysis (I2=93%; heterogeneous), and the results showed less MBL around bone-level implants compared to tissue-level group (WMD=-0.21mm; 95% CI -0.42, 0.00; P=0.06). CONCLUSION: The available data regarding comparison of MBL around bone-level and tissue-level implants are heterogeneous. Bone-level implants with platform switching may better preserve crestal bone.

Effect of Microthread Design on Marginal Bone Level Around Dental Implants Placed in Fresh Extraction Sockets.

PURPOSE: This study was designed to compare radiographically the effect of microthread on the coronal portion of the fixture on marginal bone level (MBL) around immediately placed dental implants in human subjects. MATERIAL AND METHODS: Forty-one roughened surface screw type Dentium oral implants (Dentium) were inserted in fresh extraction sockets of the anterior segment of maxilla of 30 patients. The implants were selected randomly using either microthread design on coronal portion of the fixture (Implantium) (test group) or without microthread thread design (Superline) (control group). MBL was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: At month 3, the microthread groups have been associated with more marginal bone loss than the control group (P = 0.04). At months 6 and 12, both groups had comparable bone levels (P = 0.21). CONCLUSION: The microthread design of the implant collar could not have a positive effect in maintaining the MBL around implants placed in fresh extraction socket in anterior maxilla.

Comparison of amnion allograft with connective tissue graft for root coverage procedures: a double-blind, randomized, controlled clinical trial.

OBJECTIVE: The aim of the present double-blind, randomized, controlled study was to evaluate and compare the efficacy of amnion allograft and connective tissue graft in covering denuded root surfaces. METHODS: Seventy-one teeth in 22 patients with gingival recession were treated randomly with coronally displaced flap plus connective tissue graft (control group, n = 29 recessions in 10 patients) or coronally displaced flap plus amnion allograft (test group, n = 42 recessions in 12 patients). The amount of root coverage and clinical parameters (probing depth, recession depth, clinical attachment level, recession width, gingival width, and papilla dimensions) were measured at baseline and at 3 and 6 months postoperatively. RESULTS: Average root coverage percentages after 6 months in the test and control groups were 67% (2.3 +/- 0.289 mm) and 54% (2.24 +/- 0.519 mm), respectively, with no statistically significant differences (p = 0.054). The changes in depth and width of recessions and in gingival width were significant 3 and 6 months after surgery compared to baseline (p = 0.000). Variations in the level of attachment and probing depths after 6 months were statistically significant in the test group compared to the control group (p = 0.002). Papilla dimensions were significantly correlated with root coverage (p = 0.00). CONCLUSIONS: Amnion allograft might be a suitable alternative to connective tissue graft in procedures to cover denuded root surfaces and can reduce recession depth.

A comparative study of crestal bone loss and implant stability between osteotome and conventional implant insertion techniques: a randomized controlled clinical trial study.

PURPOSE: The aim of this prospective randomized controlled clinical study was to assess the crestal bone loss and the implant stability in implants that were placed by the osteotome technique compared with the conventional drilling technique. MATERIALS AND METHODS: Forty-six screw type Straumann SLA® oral implants (Straumann AG, Waldenburg, Switzerland) were inserted in the anterior segment of maxilla of 30 patients. The implant site was prepared randomly using either osteotome technique (test group) or the conventional drilling technique (control group). Radio frequency analysis (RFA) values at implant placement and after 3 months were recorded. The crestal bone loss was measured using digital subtraction radiography technique after 3, 6, and 12 months. RESULTS: RFA demonstrated a statistically significant higher primary stability for implants in the osteotome group than that of the conventional group (p=.026) at the time of implant insertion. However, there was no statistically significant difference between both groups 3 months after the surgery (p=.06). At month 3, the osteotome group caused significantly more crestal bone loss than the conventional group (p=.04). At months 6 and 12, both groups had comparable bone levels (p=.29). CONCLUSION: Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.

The effect of platelet-rich plasma on healing of palatal donor site following connective tissue harvesting: a pilot study in dogs.

BACKGROUND: Peri-implant plastic surgery includes soft tissue enhancement by connective tissue grafting. The palatal donor site provides peri-implant keratinized mucosa and soft tissue height. Platelet-rich plasma (PRP) contains growth factors that may enhance early healing. PURPOSE: The present animal study investigated the effect of PRP on wound healing of palatal donor site after connective tissue harvesting. MATERIALS AND METHODS: In 12 mongrel dogs, bilateral palatal connective tissues of 10 × 15 mm were harvested. At test site, PRP was applied into the wound, and the contralateral site served as control. The healing was evaluated clinically and histologically at 1 week, 2 weeks, and 4 weeks after surgeries. Exact binomial probability and Wilcoxon signed-rank test were used to compare the clinical and histologic measurements. RESULTS: No statistically significant differences between PRP and control sites were measured with regard to clinical healing (p = 1.000) and histologic variables, including inflammatory cells (p = .750), collagen fibers (p = .375), and granulation tissue (p = .500) at any time interval. CONCLUSION: The addition of PRP to palatal mucosal wound sites did not accelerate wound healing.

Implant placement in patients with oral bisphosphonate therapy: a case series.

BACKGROUND: Although the effect of bisphosphonates on dental implant osseointegration is not clear, dental implant failures attributable to oral bisphosphonate therapy have been reported in patients with osteoporosis. PURPOSE: The aim of this study was to evaluate implant survival in patients with a history of bisphosphonate therapy in a retrospective survey. MATERIALS AND METHODS: A total of 46 ITI implants placed in 21 osteoporotic patients (females; average age 53 years, range 42-79 years) were evaluated with regard to probing depth, mobility, thread exposure, and bleeding on probing. All patients were under oral bisphosphonate therapy. RESULTS: None of implants showed mobility and all patients could be considered free from peri-implantitis. Time of bisphosphonate therapy before and after implant insertion showed no statistically significant influence on PD, BOP, and TE. Likewise, implant location, prosthetic type, and opposing dentition had no statistically significant influence on the clinical and radiological parameters of implants. CONCLUSION: Within the limitations of this study, it could be concluded that neither being on oral bisphosphonate treatment before implant placement nor starting bisphosphonate therapy after implant installation might jeopardize the successful osseointegration and clinical and radiographic condition of the implants.