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.

Comparing effectiveness of rubber dam and gingival displacement cord with copy abutment in reducing residual cement in cement-retained implant crowns: A crossover RCT.

OBJECTIVE: To evaluate the amount of residual cement after cementation of implant crown abutments with rubber dam and retraction cord with copy abutments techniques. MATERIAL AND METHODS: Thirty single posterior metal-ceramic implant-supported restorations were delivered to 20 patients. The crowns were fabricated with occlusal openings obturated with composite, and then luted with resin-reinforced glass-ionomer cement on customised standard abutments. The cementation procedure was performed twice in the same specimens using rubber dam (group 1) and retraction cord with copy abutment (group 2). If no cement remnants were seen on periapical radiographs after cleaning, the crown-abutment unit was dismounted. All quadrants of the specimens were photographed to calculate the percentage proportions of residual cement area. Mann-Whitney and Kruskal-Wallis tests were used for statistical analysis. RESULTS: In each group, 120 measurements were performed (30 implants, 4 surfaces each). The median percentage ratio with interquartile range (IQR) between the cement remnant area and total specimen area was 1.39% (IQR 0.77%-2.29%) and 0.58% (IQR 0.31%-1.33%) in groups 1 and 2, respectively. Lesser cement remnants were found in group 2 with a statistically significant difference (p < .001). The comparison of the mesial, distal, buccal, and lingual surfaces in each group showed no statistically significant differences between them (group 1, p = .482; group 2, p = .330). CONCLUSIONS: The retraction cord and copy abutment reduced the excess cement more efficiently than the rubber dam did. Notwithstanding, undetected cement remnants were observed with both methods, and neither should be considered reliable in clinical applications.

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.

Clinical and Histologic Evaluations of Porcine-Derived Collagen Matrix Membrane Used for Vertical Soft Tissue Augmentation: A Case Series.

This case series aimed to clinically and histologically evaluate porcine-derived membrane used for vertical thickening of thin soft tissues. Twenty porcine-derived collagen membranes and bone-level implants were placed in 20 patients. After 2 months, thickened soft tissues were measured and biopsy samples were harvested. All xenografts healed successfully. The average thickness of thin soft tissue before vertical thickening was 1.65 ± 0.36 mm, while tissue thickness increased to 3.45 ± 0.52 mm after the procedure (P < .001); the mean thickness increase was 1.8 ± 0.13 mm. Histologic analysis showed complete integration of the graft and no differences (P = .4578) in vascularization between the host (39.74 ± 17.15 vessels/mm2) and graft (30.43 ± 11.26 vessels/mm2). It can be concluded that porcine-derived membrane can be used for vertical soft tissue thickening with substantial gain in tissue height.

The use of a porcine-derived collagen matrix for vertical soft tissue augmentation. A case report.

Soft tissue augmentation is a well-established procedure employed in a diverse range of applications such as soft tissue thickening, keratinized tissue augmentation, improvement of the esthetics of existing dental implants and teeth, and crestal bone preservation around implants. This case report describes a technique for the augmentation of vertically thin soft tissue in the lower jaw posterior area. At the time of the implant placement, after measuring the soft tissue thickness, soft tissues were augmented with a porcine accellular dermal matrix (Mucoderm, Botiss Biomaterials, Germany). After 2 months, during the second stage surgery, the implant was exposed and the soft tissue thickness was measured.

Bone augmentation and simultaneous soft tissue thickening with collagen tissue matrix derivate membrane in an aesthetic area. A case report.

Aesthetic implant restoration in the anterior maxilla is a challenge for clinicians. Alveolar ridge and surrounding gingiva deficiencies aggravates implant placement in the aesthetic area. This case report describes a technique for aesthetic single implant placement with simultaneous bone grafting and soft tissue thickening. At the time of implant surgery, allogenic (Maxgraft, Botiss Biomaterials, Germany) and xenogenic bone substitute (Cerabone, Botiss Biomaterials, Germany) was used for bone grafting, soft tissues were augmented simultaneously with collagen tissue matrix derivate membrane (Mucoderm, Botiss Biomaterials, Germany). After 4 months during second stage surgery the implant was exposed. Subsequently healing abutment was replaced with provisional crown for gingival contouring. An individual zirconia abutment was made and a cemented full-ceramic crown was placed for final restoration. The 12-month follow-up check-up revealed a pleasing aesthetic treatment outcome, as well as clinically healthy peri-implant soft tissues. Radiological examination showed a stable bone crest with minor bone remodelling around the implant platform. The use of an collagen tissue matrix derivate, simultaneously with GBR, in the aesthetic area can provide excellent results, by establishing and maintaining facial bone wall and thick soft tissue in aesthetic area.