Effects of intentional early dense-polytetrafluoroethylene membrane removal on vertical ridge augmentation.

BACKGROUND: Vertical ridge augmentation (VRA) requires long healing times for bone maturation. This case study deals with the intentional early removal of a titanium-reinforced dense polytetrafluoroethylene (TR-dPTFE) membrane that allowed for treatment times reduction and improvement of bone quality. METHODS: A TR-dPTFE membrane was used for VRA in the premolar region of the upper right maxilla. The defect was filled with a mix of particulate autogenous bone and porcine xenograft in a 1:1 ratio. After a 4-month uneventful healing period, the membrane was removed, and the thick keratinized palatal tissue was moved toward the buccal side via a pedicle flap. Implants insertion and healing abutments application were carried out 3 months later, when bone graft could have been revascularized and nourished by the periosteum. RESULTS: The histologic evaluation of a bone sample harvested during implant bed preparation revealed a huge amount of mature newly formed bone even in the most coronal part. Two screw-retained crowns were delivered 2 months after implant insertion and the 3.5-year follow-up showed perfectly maintained hard and soft tissues. CONCLUSIONS: Intentional early removal of TR-dPTFE membrane after a 4-month healing time, with simultaneous soft tissue augmentation via a buccally reposioned pedicle flap, allowed graft revascularization from the periosteum, and resulted in optimal quantity and quality of the regenerated bone. This process shortened the overall treatment times, taking only 9 months from VRA to prosthetic loading. Both augmented hard and soft tissues allowed for crestal bone maintenance around implants. KEY POINTS: Titanium-reinforced dense polytetrafluoroethylene (TR-dPTFE) membranes, due to their closed structure, do not allow the passage of cells and vessels from the periosteum, and revascularization from the residual bone alone is not enough for proper graft maturation and long-term crestal bone maintenance. Early removal of TR-dPTFE membrane allows graft revascularization from the periosteum, and results in optimal quantity and quality of the regenerated bone. Increasing the thickness of the soft tissues, increasing the width of the keratinized mucosa, and repositioning the mucogingival line, via a free gingival graft or a pedicle flap, should be performed simultaneously in the membrane removal phase to reduce the number of surgical interventions, decrease patient morbidity, and shorten the total treatment time.

Exposure management of a titanium-reinforced dense polytetrafluoroethylene mesh used in a vertical ridge augmentation: A case report with 1-year follow-up.

INTRODUCTION: A new titanium-reinforced dense polytetrafluoroethylene mesh (TR-dPTFEM) has recently been introduced for vertical ridge augmentation (VRA). Since primary closure is required, the literature lacks information on its behavior in case of premature exposure. To the author's knowledge, this is the first report about TR-dPTFEM complication management. CASE PRESENTATION: A TR-dPTFEM was used for the VRA in the molar region of the upper right maxilla. The defect was filled with a mix of particulate autogenous bone and porcine xenograft in a 1:1 ratio. A collagen membrane covered the hole pattern of the TR-dPTFEM to prevent soft tissue growth within the grafted material during the first weeks. After a 4-month uneventful healing period, a 4-mm exposure occurred without infection. Patient was prescribed 0.2% chlorhexidine mouth rinse three times a day and manual cleansing with gauze soaked in 3% hydrogen peroxide, and was recalled for weekly follow-up. One month later, the clinical situation was unchanged and the site was re-entered. After TR-dPTFEM removal, the regenerated tissue appeared to be covered with a thin layer of connective tissue. The favorable bone quality made it possible to obtain the primary stability of two implants. At implant uncovering, a gingival graft augmented the keratinized mucosa width. Two screw-retained crowns were delivered 4 months after implant insertion and the 1-year follow-up showed perfectly maintained hard and soft tissues. CONCLUSION: A late TR-dPTFEM exposure, managed under strict hygiene control, did not affect this VRA. The augmented bone remained stable 1 year after prosthetic loading. KEY POINTS: Why is this case new information? A novel titanium reinforced PTFE mesh has been recently introduced for vertical ridge augmentation. This case report adds new information to the literature about the management and clinical outcome in a case of exposure. What are the keys to successful management of this case? Weekly check-up of the patient by the clinician Patient's ability to keep the wound clean and disinfected What are the primary limitations to success in this case? Impossibility of being able to check the patient at least once a week Acute infection.

Statements and Recommendations for Guided Bone Regeneration: Consensus Report of the Guided Bone Regeneration Symposium Held in Bologna, October 15 to 16, 2016.

INTRODUCTION: In the past 10 years, long-term studies have demonstrated that guided bone regeneration (GBR) is a successful and reliable technique for vertical and horizontal ridge augmentation, but strict and rigorous protocols must be adopted. MATERIAL AND METHODS: Because no reports have yet been published with statements and clinical recommendations for GBR, a closed meeting of all authors was organized to discuss this matter during a GBR symposium held in Bologna (Italy) in October 2016. The authors focused on the findings of systematic and narrative reviews, prepared before the meeting, covering aspects of the clinical management of GBR techniques. Successively, a discussion based on the scientific evidence and on the experts' opinions led to the formulation of statements, clinical recommendations, and implications for future research. RESULTS: To avoid complications and to optimize outcomes, the following factors should be considered by clinicians: patient selection; analysis of defect type; blood supply; antibiotic treatment; flap passivation; delayed implant placement; combination of autogenous bone and xenograft or allograft; rigorous fixation of membranes; removal after 6 to 9 months; analysis of complications; soft-tissue management; and high care in scarred sites and in esthetic areas. CONCLUSIONS: The present consensus report reviewed the scientific evidence and provided specific guidelines and recommendations for clinical practice and the different approaches to GBR techniques to ensure surgical success and predictable outcomes.

Histologic and Histomorphometric Analysis of Bone Regeneration with Bovine Grafting Material after 24 Months of Healing. A Case Report.

Anorganic bovine bone mineral matrix (ABBMM) has been reported to have osteoconductive properties and no inflammatory or adverse responses when used as grafting material in sinus augmentation procedures. However, controversy remains in regard to degradation rate of ABBMM. The aim of this study was to histologically and histomorphometrically evaluate the degradation of ABBMM in human bone samples obtained in one patient 24 months after sinus augmentation. MATERIALS AND METHODS: The histologic and histomorphometric analysis was performed by means of light microscopy in three specimens harvested from the same patient, Results: After 24 months the tissue pattern appeared to be composed of residual particles, some in close contact with the newly formed bone, others separated by translucent areas and osteoid tissues. Newly-formed bone presented different levels of maturation and numerous osteocytes, with greater numbers in bone closer to the grafted particles (27.3% vs. 11.2%, p < 0.05). The histomorphometric analysis showed mean values of 40.84% newly-formed bone, 33.58% residual graft material, 23.84% marrow spaces, and 1.69% osteoid tissue, Conclusions: Even though ABBMM underwent considerable resorption, a great amount of residual grafting material was still present after two years of healing following sinus augmentation. This study confirms that the bovine grafts can be classified as long-term degradation materials.

Clinical, Radiographic, and Histologic Evaluation of Maxillary Sinus Lift Procedure Using a Highly Purified Xenogenic Graft (Laddec(®)).

OBJECTIVES: The aim of this study was to evaluate the clinical, radiographic and histologic results when a highly purified xenogenic bone (Laddec(®)) was used as grafting material in maxillary sinuses. MATERIAL AND METHODS: In fifteen patients requiring unilateral maxillary sinus augmentation, the grafting procedure was performed with Laddec(®). Forty-two implants were installed after a 6 month healing period. The height of the augmented sinus was measured radiographically immediately after augmentation and postoperatively up to 36 months. At the time of implant placement, a bone core was harvested in each patient for histological examination. RESULTS: The cumulative implant survival rate was 97.6%. The original height was 3.65 (SD 0.7) mm and the augmented sinus height was 13.8 (SD 1.4) mm after the surgery. The reduced height of grafted xenogenic material (RDL) at the implant insertion was 0.83 (SD 0.38) mm, and at the final postoperative visit was 0.91 (SD 0.25) mm, showing no significant correlation with the follow-up periods by Spearman's test (P = 0.118). In addition, no significant difference in the RDL was observed according to the site of implantation (P = 0.682). The mean implant marginal bone loss was 0.38 (SD 0.24) mm. Histological analysis showed the bone cores were composed of 64.72 (SD 3.44)% newly formed bone, 17.41 (SD 2.02)% connective tissue, 16.93 (SD 2.83)% residual graft particles, and 0.94 (SD 0.11)% inflammatory cells. CONCLUSIONS: According to our data, the highly purified xenogenic bone (Laddec(®)), used as graft material in the sinus lift procedure, may create adequate bone volume, and appropriate osseointegration of dental implants.

Immediate versus Delayed Treatment in the Anterior Maxilla Using Single Implants with a Laser-Microtextured Collar: 3-Year Results of a Case Series on Hard- and Soft-Tissue Response and Esthetics.

PURPOSE: To compare peri-implant marginal bone loss, soft tissue response, and esthetics following single immediate implant treatment (IIT) and delayed implant treatment (DIT) in the esthetic zone of the maxilla in well-selected patients. MATERIALS AND METHODS: Adequate bone volume and ideal soft tissue level/contour were considered requirements for implant therapy, with additional prerequisites for IIT of residual alveolar bone wall integrity and a thick gingival biotype. IIT included immediate placement and provisionalization, while DIT included extraction socket preservation followed by implant placement and provisionalization 4 months later. Cortical bone levels and peri-implant mucosal conditions were evaluated at regular intervals. The esthetic outcome was objectively rated after 3 years using the pink esthetic score (PES) and white esthetic score (WES). RESULTS: Twelve patients received an immediate Laser-Lok® implant, and 13 patients received a delayed Laser-Lok® implant. No significant differences were found between the study groups regarding survival rate (100%). The mean bone level from the implant/abutment interface was 0.35 ± 0.18 mm for IIT and 0.42 ± 0.21 mm for DIT after 3 years (p > 0.05). Mesial and distal papillae remained stable over time in DIT. A tendency for regrowth of mesial and distal papillae was found following IIT (p < 0.05). Midfacial soft tissues remained stable over time following DIT and IIT. CONCLUSIONS: Within the limitations of this study (e.g., small sample size, short follow-up duration), the results suggest that regarding success rate, hard/soft tissue responses, and esthetics, DIT and IIT with single Laser-Lok® implants in the anterior maxilla are comparable and predictable options for well-selected patients.

GBR using cross-linked collagen membrane and a new highly purified bovine xenograft (Laddec) in horizontal ridge augmentation: Case report of clinical and histomorphometric analysis.

This case report presents the clinical and histologic evaluation of the application of a cross-linked collagen membrane and a new highly purified bovine xenograft with type 1 collagen fiber preservation (Laddec) in mandibular horizontal ridge augmentation on a 50-year-old woman. Significant bone volume was achieved to restore severe bone defect in order to place two implants. Histomorphometric analysis of a bone core at the augmented site, at 6 months, showed new bone formation with bone substitute particles integrated to new viable bone.