Soft tissue augmentation applying a collagenated porcine dermal matrix during second stage surgery: A prospective multicenter case series

BACKGROUND The achievement and preservation of an adequate amount of soft tissue around implants is a critical factor for the prognosis of the treatment. PURPOSE To evaluate the effectiveness of a porcine dermal matrix applied during second stage implant surgery for horizontal soft tissue augmentation and preservation of dimensional stability. MATERIALS AND METHODS Twenty patients (mean age 50.2 ± 11.9 [SD] years) candidate to implant therapy and requiring soft tissue augmentation were recruited in four centers. Augmentation was performed in 24 cases. A porcine dermal matrix was placed into a buccal split-thickness pouch during uncovering surgery. Silicone impressions were taken before surgery (T0), 2 weeks later at suture removal (T2), 6 months (T3), and 24 months (T4) post augmentation. Dimensional changes of soft tissue were evaluated using superimposition of digitalized study casts. RESULTS Nineteen patients (23 implants) could be evaluated at 6 months and 13 patients (17 implants) at 24 months. After 6-month follow-up, there was a significant dimensional gain respect to baseline, averaging 0.83 ± 0.64 mm (P 0.5 mm in 65.2% and 64.7% of the cases, respectively. Soft tissue shrinkage averaged 34.2% ± 77.0% from T2 to T3 (P < .01) and did not change thereafter (P = .39). Shrinkage was more consistent in the posterior mandible than in the maxilla, but not significantly (P = .23 at 6-month and .36 at 24-month). No adverse events occurred. CONCLUSION Within the limitations of this prospective case series, the use of a porcine dermal matrix may provide consistent soft tissue augmentation that maintains up to 24-month follow-up, although graft shrinkage may occur in the first 6 months, depending on the location of surgery

Biomechanical aspects:Summary and consensus statements of group 4. The 5(th) EAO Consensus Conference 2018

Objectives: The aim of the present publication was to report on the EAO Workshop group-4 discussions and consensus statements on the five reviews previously prepared. These reviews provided the scientific evidence on the effect of crown-to-implant ratio, on reconstructions with cantilevers in fully and partially edentulous patients, on biological and technical complications of tilted in comparison with straight implants, and on the effects of osseointegrated implants functioning in a residual dentition. Material and Methods: The group discussed, evaluated, corrected where deemed appropriate, and made recommendations to the authors regarding the following five reviews submitted: (a) Is there an effect of crown-to-implant ratio on implant treatment outcomes?; (b) Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients; (c) and in partially edentulous patients; (d) Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses; (e) What are the adverse effects of osseointegrated implants functioning among natural teeth of a residual dentition? Based on the five manuscripts and the discussion among the group as well as the plenum members, the major findings were summarized, consensus statements were formulated, clinical recommendations were proposed, and areas of future research were identified. Results: Crown-to-implant ratios ranging from 0.9 to 2.2 did not influence the occurrence of biological or technical complications also in single-tooth restorations. Reconstructions with cantilevers for the rehabilitation of fully and partially edentulous jaws showed high implant and reconstruction survival rates. In contrast, the rate of complications\u2014in particular associated with veneering material\u2014was high during the observation period of 5\u201310\ua0years. The data reported were primarily derived from studies with high risk of bias. The data for single-implant reconstructions were small. There was no evidence that distally tilted implants were associated with higher failure rates and increased amounts of marginal bone loss. The data supporting these findings, however, were at high risk of bias and frequently incompletely reported. Frequent positional changes occurred between the natural teeth and the implant-supported restorations. These changes were more pronounced in younger individuals, and even though they were reduced with age, they still occurred in adult patients. Even though these changes were frequent, potential implications for the patient are unclear. Conclusions: The use of single-tooth restorations with crown-to-implant ratio in between 0.9 and 2.2 may be considered a viable treatment option. Multiunit reconstructions with cantilevers are a viable treatment option in fully and partially edentulous patients. Clinicians and patients should be aware, however, that complications are frequent and primarily related to resin material used for veneering. There is some evidence that tilting an implant does affect stability of the implant and the surrounding bone. Treatment options to tilted implants should carefully be considered, as the effect on soft tissues and on prosthesis behavior is poorly reported for tilted implants. Positional changes in the dentition in relation to implant-supported restorations occur frequently. The patient should be informed about the possible need for a treatment related to these changes in the long term

Multi-Layer Technique (MLT) with Porcine Collagenated Cortical Bone Lamina for Bone Regeneration Procedures and Immediate Post-Extraction Implantation in the Esthetic Area: A Retrospective Case Series with a Mean Follow-Up of 5 Years

Background: Augmentation of the edentulous atrophic anterior region is a challenging situation. The purpose of this article was to evaluate the effectiveness of a collagenated cortical bone lamina of porcine origin for horizontal ridge augmentation in patients with inadequate alveolar ridge width undergoing immediate post-extraction implantation in the anterior sites, and to report on implant survival rates/complications. Materials and methods: The cases were extracted electronically from a large database according to these specific inclusion criteria: patients with inadequate alveolar ridge width in the anterior maxilla or mandible, who underwent immediate post-extraction implant placement and simultaneous alveolar bone reconstruction using xenogeneic cortical bone lamina. An additional layer of palatal connective tissue graft was inserted between lamina and the vestibular mucosa, for improving soft tissue healing. A collagenated bone substitute was additionally placed in the gap between the lamina and implant surface in all patients. The main outcomes were implant survival and complications. Results: Forty-nine patients with 65 implants were included. Patients’ mean age at the time of implant surgery was 60.0 ± 13.6 years. The mean follow-up was 60.5 ± 26.6 months after implant placement. The implant survival was 100%. Four postoperative complications occurred in four patients. No specific factor was found to be associated with complication occurrence. Conclusion: The use of collagenated cortical bone lamina can be considered as a successful option for alveolar reconstruction in immediate post-extraction implant insertion procedures in anterior regions with inadequate alveolar ridge width

Perceptions and realities of elephant crop raiding and mitigation methods

Crop raiding by African elephants (Loxodonta africana) jeopardizes human livelihoods and undermines conservation efforts. Addressing this issue is particularly important in subsistence farms adjacent to protected areas and requires assessing the perceived and actual scale of the problem and the benefits, limitations and adoption potential of mitigation techniques. To achieve these objectives, we assessed the effectiveness of chili and beehive fences relative to control plots, using a daily farm monitoring protocol implemented on 20 farms bordering the Ngorongoro Conservation Area (Tanzania). Prior to the field study, we interviewed 65 farmers about human–elephant interactions and contrasted interview findings with those of daily farm monitoring. Farmer perception of crop raiding frequency declined with increasing distance from the protected area and was, on average, eight times greater than daily farm monitoring data indicated. The majority of interviewees expressed a willingness to try chili or beehive fences, though chili fences were preferred. Generalized-linear-mixed models indicated that neither elephant farm intrusions nor damages were significantly reduced by either chili or beehive fences relative to the control sites. Losses per month and hectare did not differ significantly by fence type. However, farm plots with chili fences did not experience massive damages which occasionally occurred in beehive or control plots. This partial effectiveness of chili fences was further confirmed by contrasting crop losses from a subset of farms that were subject to a cross-over experimental design. Our multidimensional case study suggests that chili fences have greater adoption potential than beehive fences. Nevertheless, additional efforts are required to increase effectiveness and to realize adoption potential. By providing insights into the context and circumstances that presented challenges to the effectiveness, sustainability and scalability of beehive and chili fences, this study can serve as reference for areas where crop raiding by elephants is a key conservation conflict

Xenogenic collagen matrix or autologous connective tissue graft as adjunct to coronally advanced flaps for coverage of multiple adjacent gingival recession: Randomized trial assessing non-inferiority in root coverage and superiority in oral health-related quality of life

Aim: To evaluate the non-inferiority of the adjunct of a xenogeneic collagen matrix (CMX) or connective tissue graft (CTG) to coronally advanced flaps (CAF) for coverage of multiple adjacent recessions and compare superiority in patient-reported outcomes (PROM). Material and methods: One hundred and eighty-seven subjects (92 CMX) with 485 recessions in 14 centres were randomized and followed up for 6 months. Patients filled daily diaries for 15 days to monitor patient-reported experience. The primary outcome was changed in position of the gingival margin. Multilevel analysis used centre, subject and tooth as levels and baseline parameters as covariates. Results: Average baseline recession was 2.5 ± 1.0 mm. The surgery was 15.7 min shorter (95%CI from 11.9 to 19.6, p <.0001) and perceived lighter (11.9 VAS units, 95%CI from 4.6 to 19.1, p =.0014) in CMX subjects. Time to recovery was 1.8 days shorter in CMX. Six-month root coverage was 1.7 ± 1.1 mm for CMX and 2.1 ± 1.0 mm for CTG (difference of 0.44 mm, 95%CI from 0.25 to 0.63 mm). The upper limit of the confidence interval was over the non-inferiority margin of 0.25 mm. Odds of complete root coverage were significantly higher for CTG (OR = 4.0, 95% CI 1.8â\u80\u938.8). Conclusion: Replacing CTG with CMX shortens time to recovery and decreases morbidity, but the tested generation of devices is probably inferior to autologous CTG in terms of root coverage. Significant variability in PROMs was observed among centres