Clinical efficacy of two vertical soft tissue augmentation techniques for peri-implant crestal bone level stability: A randomized clinical trial.

OBJECTIVES: This study aimed to compare the efficacy of two techniques-acellular dermal matrix (ADM) grafting and tenting technique (TT)-for soft tissue height (STH) augmentation simultaneous to implant placement to minimize peri-implant crestal bone level (CBL) changes. METHODS: Forty patients with a healed single mandibular posterior edentulous site with a thin soft tissue phenotype were enrolled. Twenty patients received simultaneously to implant placement ADM grafting, while the others received submerged healing abutment (TT). Clinical peri-implant soft tissue height and radiographic CBL changes were measured at restoration delivery and 1-year follow-up. RESULTS: Both techniques effectively increased soft tissue thickness, resulting in a final average STH of 3.4 ± 0.5 mm after augmentation. On average, soft tissue increased by 1.6 ± 0.5 mm in group ADM and by 1.8 ± 0.4 mm in group TT after augmentation. In Group ADM, mesial CBL decreased from 0.4 ± 0.3 mm to 0.1 ± 0.2 mm, and distal CBL decreased from 0.5 ± 0.3 mm to 0.2 ± 0.3 mm over 1 year. In Group TT, mesial CBL remained stable at 0.3 ± 0.2 mm, while distal CBL reduced slightly from 0.5 ± 0.5 mm to 0.3 ± 0.2 mm. Both groups showed minimal changes in CBL, indicating great stability (pmesial = 0.003, pdistal = 0.004). TT was particularly effective in preventing mesial bone loss (pmesial = 0.019). The mesial CBL changes significantly differed between groups (p = 0.019), and not significantly at distal sites (p = 0.944). Neither treatment exhibited significant bone remodeling below the implant shoulder. CONCLUSION: This study suggests that both techniques were successful in STH augmentation, and they may effectively reduce peri-implant crestal bone level changes, with TT being slightly superior. TT was more prone to post-surgical complications. This RCT was not registered before participant recruitment and randomization.

Influence of mucosal tissue height on implant crestal bone: A 10-year follow-up of a controlled clinical trial.

OBJECTIVE: To evaluate the 10-year influence of soft tissue height (STH) on crestal bone level changes (CBC) in bone-level implants with non-matching internal conical connections. MATERIAL & METHODS: From the initial 97 patients, 59 (19 men, 40 women, age 55.86 ± 9.5 years) returned for the recall visit. Based on baseline STH, they were categorized into T1 (thin STH ≤2 mm, n = 33), T2 (thin STH augmented with allogenic tissue matrix (ATM), n = 32), and C (thick STH >2 mm, n = 32). Implants were placed in the posterior mandible using a one-stage approach and received single screw-retained restorations. Clinical (PPD, BOP, PI) and radiographic examinations were conducted after 10 years, with CBC calculated mesial and distal to each implant. RESULTS: After 10 years, implants in surgically thickened (T2) or naturally thick STH (C) showed bone gains of 0.57 ± 0.55 mm and 0.56 ± 0.40 mm, respectively (p < 0.0001) shifting from an initial CBC of -0.21 ± 0.33 mm to 0.36 ± 0.29 mm in the thick STH group and -0.2 ± 0.35 mm to 0.37 ± 0.29 mm in the surgically thickened STH group. Implants in naturally thin STH yielded a non-significant trend of bone loss (-0.12 ± 0.41 mm; p > 0.05). CONCLUSIONS: Implants in thin STH (≤2 mm) exhibited greater CBC over the study period. Significant bone gains were observed in thick STH cases, indicating that naturally thick STH or STH augmentation with ATM may contribute to maintain CBC in long-term around implants. CLINICAL SIGNIFICANCE: This is the first long-term follow-up study suggesting that adequate soft tissue height around implants helps maintain stable peri­implant bone levels. While tissue thickness plays a key role, other factors also interact with peri­implant tissue height to sustain crestal bone stability over time.

Influence of Cement Type on its Quality of Removal from Zirconium Oxide Implant-Supported Restorations

PURPOSE: To assess excess cement removal after cementation of implant-supported cementretained restorations using different cements. MATERIALS AND METHODS: A dental model with soft tissue imitation, 20 individual zirconium oxide abutments, and 20 zirconium oxide crowns were fabricated. Half of the restorations were cemented using resin cement (RX) and the other half with resin-modified glass-ionomer cement (GC). After cement cleaning, each crown-abutment unit was removed from the model, photographed, and analyzed from 4 surfaces, resulting in a final sample size of 80 measurements. Radiographic examination and the computerized planimetric method in Adobe Photoshop were used to determine the amount of the cement left and to evaluate the ratio between the area of cement residue and the whole crown-abutment surface. The significance was set to .05. RESULTS: GC resulted in 7.4% more cement residue on all surfaces (P < .05) than RX. The P value on three of the surfaces (all except mesial) was < .05, meaning that the data were statistically significantly different between groups and surfaces. Absolute removal of the cement was impossible in all cases (100%), and in 95% of the cases, cement remnants could not be detected radiographically. CONCLUSION: More undetected cement remains when using resin-modified glass-ionomer cement. It was impossible to remove excess of both types of cements completely. Most of the cement remains on the distal surface. Radiographic examination could not be considered as a reliable method to identify excess cement.

Immediate implant placement vs. early implant treatment in the esthetic area. A 1-year randomized clinical trial.

OBJECTIVES: To assess the impact of implant placement and temporization timing on esthetic outcomes of single maxillary anterior implants with intact bone walls and interproximal bone. MATERIALS AND METHODS: Test group patients received an immediate implant with immediate provisional restoration and socket preservation, while patients in the control group received an early implant placement with guided bone regeneration and delayed loading. Patients were followed for 1 year after final prosthetic and pink esthetic score (PES), mid-buccal mucosal level (MBML), crestal bone changes (CBC), and peri-implant soft tissue parameters, and patient chair time was recorded. RESULTS: Fifty patients received the intended treatment (25 test and 25 control). No implants failed. PES after 1 year was 12.8 ± 1.19 for the test group and 12.5 ± 1.36 for the control group (p = .362). MBML difference between baseline (after final crown delivery) and the 1-year follow-up was gain of 0.2 ± 1.02 mm for the test group (p = .047) and no change in the control group. CBC after 1 year were 0.1 mm ± 0.21 mm (mesial) and 0.2 mm ± 0.22 mm (distal) for the test group and 0.2 mm ± 0.25 mm (mesial) and 0.3 mm ± 0.19 mm (distal) for the control group, p = .540 (mesial) and p = .462 (distal). Test group required half the chair time (127 ± 13 min) when compared to the control group (259 ± 15 min, p < .001). CONCLUSIONS: Within the limits of this trial, both treatment protocols resulted in excellent esthetic outcomes with PES >12 after 1-year follow-up.

Connective tissue graft vs porcine collagen matrix after immediate implant placement in esthetic area: A randomized clinical trial.

BACKGROUND: The use of connective tissue graft (CTG) with immediate implant placement and provisionalisation have shown promising results. It is not clear if the same outcome could be achieved using porcine-derived collagen matrix (PDCM) as grafting material. OBJECTIVES: This study aimed to assess the esthetic and functional outcomes of immediate temporization of immediately placed fully tapered implants combined with bone and soft tissue augmentation, using either a CTG or a PDCM, in fresh extraction sockets of the anterior sites. MATERIALS AND METHODS: Patients with a failing anterior tooth were included in this study. After extraction, they received an immediate implant with simultaneous hard and soft tissue augmentation and immediate provisional restoration. Patients were randomly assigned to one of the group. Soft tissue augmentation in the control group (CTG) consisted of a CTG, whereas PDCM was used in the test group. After 4 months, definitive restorations were delivered, and pink esthetic score (PES) was evaluated at T1, prosthetic delivery, and at 12-month follow-up (T2). In addition, crestal bone change, probing depth, bleeding on probing, plaque index, bleeding on provisional removal, and implant stability quotient were also recorded. RESULTS: A total of 45 patients received the intended treatment (22 controls and 23 tests) 45 implants totally, with no implant failures at T2. PES mean ± SD after 1 year was noted to be 12.9 ± 1.2 for the CTG group and 12.1 ± 1.3 for the PDCM group (p = 0.507). CONCLUSION: Within the limits of this trial, both treatment protocols resulted in comparable esthetic outcomes, with results showing PES >12 and stable clinical parameters after 1 year of follow-up.

Full versus partial thickness flap to determine differentiation and over keratinization of non-keratinized mucosa. A 3-year split mouth randomized pilot study.

OBJECTIVES: It was shown, that Connective Tissue Grafts (CTG) retrieved from the tuberosity tends to determine hyperplastic responses and may induce a beneficial over-keratinization of non-keratinized mucosa. Clinically evaluate and compare CTG from tuberosity ability to increase soft tissue thickness and the keratinization potential after recipient area is either prepared using split or full thickness flap in edentulous mandible. MATERIALS AND METHODS: Fourty implants were placed in 10 edentulous patients with atrophied mandible (Class IV of Misch) presenting less than 1.0 mm of keratinized tissue using a flapless approach and immediately restored with acrylic temporary bridge on multi-unit abutments. The surgical sites were split-mouth randomized and prepared as CTG recipients by a tunneling procedure. Twenty benefited of a partial thickness approach and 20 of a full thickness one. The CTG was placed buccally using partial thickness or full thickness flap according to the randomization schedule. The width of keratinized tissue (KT), the horizontal soft tissue thickness (STT), the marginal hard and soft tissue levels as well as the implant success parameters were collected and analyzed. RESULTS: After a 3 year follow-up period the increase of KT was statistically significantly (p < 0.001) larger in the partial thickness group from 0.6(0.6) to 5.1(0.72) mm, while full thickness group showed very little improvement from 0.5(0.51) to 1(0.57) mm (p < 0.001). STT was significantly increased in both groups over time: from 2.4(0.88) to 5.4(0.68) mm in full thickness group and from 2.5(0.51) to 5.8(0.41) mm in partial thickness group without any significant difference between the groups. CONCLUSION: The increase of soft tissue thickness by using CTG from tuberosity was found in both groups, while keratinization of non-keratinized mucosa appeared more in the partial thickness group.

Influence of Implant Placement Depth and Soft Tissue Thickness on Crestal Bone Stability Around Implants With and Without Platform Switching: A Comparative Clinical Trial.

This case control study measured early crestal bone changes around subcrestally placed platform-switched implants surrounded by thin soft tissue and compared them with regular, matching-platform implants placed in a supracrestal position and surrounded by thick soft tissue. Sixty-six patients received two-piece internal hex dental implants. Control group patients (n = 33) received implants that had a horizontally matching implant-abutment connection and were placed approximately 0.5 to 1 mm supracrestally. Test group patients (n = 33) received platform-switched implants that were placed about 1.5 mm subcrestally. Clinical examinations were conducted, intraoral radiographs were taken, and statistical analysis was performed. After 2 months, the mean bone loss was 0.2 mm (SD: 0.22 mm; range: 0.1 to 1.2 mm) in the control group and -0.69 mm (SD: 0.65 mm; range: 0 to 2.6 mm) in the test group; this difference was found to be statistically significant (P < .05). After 1 year, mean bone loss was 0.28 mm (SD: 0.36 mm; range: 0.1 to 1.63 mm) in the control group and -0.6 mm (SD: 0.55 mm; range: 0.05 to 1.8 mm) in the test group. Platform-switched implants placed in a subcrestal position in vertically thin soft tissues showed statistically significantly more bone loss than non-platform-switched implants placed supracrestally with vertically thick tissues.

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

A particular technique can increase the mucosal and peri-implant bone thickness, prevent compression around implant neck, and obtain proper space for the following prosthetic treatment with an adequate emergence profile.

Crestal bone stability after flapless placement of sloped implants with immediate temporization in edentulous mandible. A prospective comparative clinical trial.

OBJECTIVES: The purpose of this study was to evaluate crestal bone stability around sloped implants using the flapless procedure and compare it with conventional implants placed axially. MATERIALS AND METHODS: A total of 40 bone-level implants with platform switching were used for this study for 10 patients (4 males and 6 females) in edentulous mandible. Twenty mesial conventional implants were placed in upright position and 20 distal 30° sloped implants tilted 30°. Bone loss was estimated using radiographic imaging after a 6- and a 12-month follow-up period. Comparison of the bone loss in the distal and mesial region at both implantation angles were conducted to understand the nature and progression of crestal bone loss. RESULTS: Crestal bone loss around the sloped implants was 0.29 mm (SD = 0.292) on average, while around conventional implants it was 0.22 mm (SD = 0.202) after one-year follow-up. However, there was no significant difference in the average of crestal bone loss between two trial groups after 6 months (p < 0.243) and one-year (p < 0.614) follow-up. The results indicated a 100% implant survival rate after one-year follow-up. Additionally, three fixed prostheses needed realignment after fracturing during the follow-up time. CONCLUSION: Considering the limitations of this study, it can be presumed that sloped and conventional implants with platform switching and conical connection have the same potential for minimal crestal bone loss.