Periodontal Biotype Influence on the Volume Maintenance of Onlay Grafts

Facial cortical bone regeneration post-extraction in non-grafted sockets allows for early implant placement and long-term functional stability

OBJECTIVE

To evaluate posterior implant placement feasibility shortly after tooth extraction in non-grafted sockets with and without dehiscence at the time of extraction.

DESIGN

Ninety-five patients requiring posterior extractions entered this cross-sectional study. They were divided in three groups after extraction: G1 without dehiscence, G2 with dehiscence ≤5 and G3 > 5 mm. CBCT were taken prior to implant placement at an average of 12-weeks post-extraction to evaluate the need for grafting, cortical bone formation and bucco-lingual width (BLW). Actual BLW (n = 60) were compared to minimum expected BLW in 3 scenarios of BLW thickness averaging 6.4-7.4-8.4 mm. Peri-implant tissues were assessed for pocket formation and inflammation following established success criteria.

RESULTS

New cortical bone formation and sufficient BLW made implant placement feasible in sites with and without dehiscence at the time of extraction after an average healing time of 11.9 ± 2.4weeks (range: 8-18). Total average CBCT BLW was 10.1 ± 1.6 mm. All groups had a significantly higher BLW, than scenarios 1-3 (p < 0.0001). Molars were 20 times more likely than premolars to heal with BLW>10 mm (OR = 20; RR = 4.2; CI95 %: 5.3-74.2; p < 0.0001). Dehiscence sockets were 1.5 times more likely than non-dehiscenced sockets to present BLW ≤ 10 mm (OR = 1.5; RR = 0.6; CI95 %:0.9-2.5; p = 0.08). A band of keratinized tissue was present in all implants and success rates were 100 % at an average follow-up of 51.0 ± 23.4 months.

CONCLUSION

Implant placement is feasible without socket grafting shortly after tooth extraction. Non-grafted sockets present a significant osteogenic potential. Dehiscence sockets are likely to self-repair by forming a new cortical plate. The unassisted regenerated intra-socket bone allows for functional implant stability long-term.

Autogenous bone block grafting provides facial implant tissue stability long-term

BACKGROUND

Mucosal recession (MR) and bone loss can compromise anterior implant esthetics.

PURPOSE

To evaluate tissue stability and clinical outcomes of anterior implants augmented with autogenous block transplants long-term.

MATERIALS AND METHODS

This prospective cross-sectional clinical study analyzed facial tissue recession of anterior implants augmented with autogenous bone blocks and compared them to adjacent teeth in forty patients 52 months post-augmentation. Clinical parameters, MR and implant transparency, were assessed at delivery and follow-up. The hypothesis is that the facial mucosa of augmented implant sites is more resistant to trauma than the gingival margins of adjacent teeth.

RESULTS

Teeth were seven times more likely to present a facial recession than adjacent augmented implants at 52-month follow-up (RR: 7; P < .001; 95%CI: 2.7-18.0). Augmented implant sites were six times more likely to present "no-tissue-recession" than adjacent teeth (RR: 6.2; P < .001; 95%CI: 2.4-15.7). Mean tooth facial tissue recession was significantly higher than adjacent implants, 1.18 ± 1.05 mm (range: 0-3.5 mm) vs. 0.06 ± 0.2 mm (95%CI: 0.8-1.5; P < .0001). Thick biotype teeth were 2 times more resistant to recession than thin biotype teeth (RR: 2.03; P = .03; 95%CI: 1.2-3.5). Implant success rates were 100%. Lack of transparency and MR at facial implant sites lasted an average of 52 months and up to 144 without signs of inflammation or pocket formation regardless of the individual's biotype. Facial bone thicknesses of 2.2 mm seem optimal for tissue stability.

CONCLUSIONS

Autogenous bone block augmentation with staged implant placement seems to be a predictable, short-healing, reconstructive protocol in the esthetic zone maintaining stable peri-implant tissues long-term. Implant augmented sites seem more resistant to develop a recession than adjacent teeth.

Immediate free iliac bone graft after nonsegmental mandibular resection and delayed implant placement: a case series

BACKGROUND

Resection of mandibular tumors without proper reconstruction may lead to unfavorable esthetic and function results. The purpose of this case series was to describe clinical results and a technique to prevent tissue loss using nonvascular iliac grafts immediately following tumor resection and long-term stability of the implants.

MATERIALS AND METHODS

Three female patients presented with oral neoplasms (2 ameloblastoma and 1 ossifying fibroma). The mandibular reconstruction was performed with nonvascularized iliac grafts simultaneous with tumor removal. Subsequently, 10 dental implants were placed 6 to 9 months after reconstruction and restored. Survival and success of the implants were evaluated.

RESULTS

Marginal mandibulectomy in 1 patient and buccal bone resection in 2 patients was performed; the resection sites were reconstructed with an immediate nonvascularized iliac graft. All implants survived and were successful during follow-up periods between 44 and 105 months. Mean marginal bone loss of 10 implants was 0.09 mm.

CONCLUSIONS

Immediate reconstruction with nonvascularized iliac grafts following tumor resection may be a viable treatment option for nonsegmental inlay osseous defects. In these case series, the resorption of the iliac bone was minimal after 6 to 9 months consolidation periods.

Soft and hard tissue management in implant therapy-part I: surgical concepts

Implant therapy has become a reliable and predictable treatment alternative for the replacement of missing teeth with conventional removable and fixed partial dentures. Recently though, in the pursuit for improved esthetics, the literature has dedicated a considerable amount of its research on the successful maintenance and regeneration of the surrounding gingiva and bone, which are lost following extraction of a tooth. Thoroughly analyzing the anatomic situation and well-planned treatment has become a requirement, because incorrectly planned and positioned implants may jeopardize long-term esthetic and functional prognosis. In addition, many types of biocompatible materials, autogenous hard and soft tissue grafts, and different surgical techniques have been developed, and their viability has been investigated. As a result, implant specialists have gained a greater understanding of the dynamics and anatomical and biological concepts of the periodontium and peri-implant tissues both at the surgical and prosthetic phases of treatment, which contributes to better soft and hard tissue management (SHTM). This may further contribute to achieving a superior final result which is obtained by having a harmonious soft tissue profile, a correctly placed and contoured final restoration, and the reestablishment of masticatory function and phonetics.

Fate of autologous and fresh-frozen allogeneic block bone grafts used for ridge augmentation. A CBCT-based analysis

OBJECTIVES

To evaluate dimensional changes in autologous (AT) and fresh-frozen allogeneic (AL) block bone grafts 6 months after alveolar ridge augmentation.

MATERIAL AND METHODS

Twenty-six partially or totally edentulous patients treated either with fresh-frozen AL bone or AT bone onlay block grafts prior to implant placement (13 patients in each group), were included in this analysis. Patients received CBCT (i-CAT Classic) examinations prior to surgery and 14 days and 6 months after grafting. Differences in alveolar ridge area among the various observation times were evaluated by planimetric measurements on two-dimensional CBCT images of the grafted regions. Nineteen grafted blocks from each group were evaluated.

RESULTS

Significant increase in alveolar ridge dimensions, allowing implant placement, was obtained with both types of grafts 6 months after grafting; no significant differences in alveolar ridge area were observed between the groups at the various observation times. However, graft resorption in the AL group was significantly larger compared to that in the AT group at 6 months.

CONCLUSIONS

Larger bone graft resorption was seen in patients treated with fresh-frozen AL bone than in those treated with AT bone 6 months following alveolar ridge augmentation.

Clinical, tomographic, and histological assessment of periosteal guided bone regeneration with cortical perforations in advanced human critical size defects

BACKGROUND

Large osseous defects that fail to heal spontaneously require ridge augmentation prior to implant placement. The periosteum can act as an effective barrier membrane. Little is known about the influence of bone decortication in enhancing guided bone regeneration outcomes.

PURPOSE

The aim of the present study was a clinical, tomographic, and histological evaluation of bone healing in large defect sites treated with cortical perforations without the use of other membranes but the periosteum.

MATERIAL AND METHODS

Ten consecutive patients undergoing ridge augmentation on the pre-maxilla due to severe bone loss were followed for an average of 35 months. Recipient sites were cortico-perforated and augmented using a combination of autogenous particulate and block grafts. The periosteal membrane was preserved and it fully covered the autografts. Histological analysis was performed in four sites from a trephine core taken at the time of implant osteotomy preparation. Tomographic assessment (computed tomography [CT] scan) at baseline and post-augmentation evaluated graft volume maintenance.

RESULTS

Recipient sites were re-entered for implant placement showing good incorporation of the grafts with minimal volume loss. Biopsy specimens showed viable bone rich in osteoblast-like cells with little or no inflammatory cells. Clinical exam revealed absence of implant transparency, mucosal recession, mobility, bleeding on probing, or suppuration at follow-up. CT scan evaluation showed an average increased bucco-lingual width at the recipient site of 8.1 mm ± 0.9 (2.5 fold) versus a 3.2 ± 0.9 at baseline (p < .0001; CI 95%: 4.04-5.71 mm), maintaining on average 98% of the augmented width at 2.9 years.

CONCLUSIONS

Periosteal preservation seems to be sufficient as a barrier membrane to protect particulate or block osseous grafts provided that good primary closure is achieved. Bone decortication may enhance clinical and histological outcomes. Graft viability (biopsy specimens) and volume maintenance (CT evaluation) remained stable 35 months post-augmentation.