International Journal of Periodontics & Restorative Dentistry, 04/2013

The aim of this case series report is to compare the results of the increase in keratinized mucosa using three different techniques of stage-two surgery. Thirty-two patients with one to eight dental implants who received prosthetic rehabilitation of the maxilla were included. Patients were divided into three groups based on preoperative anatomical considerations. Stage-two surgery was performed using either the apically repositioned flap (ARF; n = 14), the roll flap (RF; n = 10), or an apically repositioned flap combined with a connective tissue graft (ARFCT; n = 8). The height of the keratinized mucosa and relative tissue thickness were measured preoperatively and postoperatively at 2 weeks and 3, 6, and 12 months after surgery. The mean gains of keratinized mucosa and tissue thickness were calculated from these measurements. After 1 year, the mean gains in tissue thickness and keratinized tissue were 1.37 and 4.63 mm in the ARF group, 2.41 and 1.35 mm in the RF group, and 3.10 and 4.10 mm in the ARFCT group, respectively. There was no significant statistical difference between the 12-month and postoperative measurements (P > .05). In patients with deficient tissue thickness, a roll flap or an apically repositioned flap should be performed, while a lack of keratinized mucosa indicates the use of an apically repositioned flap with or without a connective tissue graft. When an increase in both keratinized mucosa and tissue thickness is necessary, an apically repositioned flap combined with a free connective tissue graft can be recommended. After a 12-month healing period, the obtained results showed excellent stability.

This clinical case report describes and demonstrates the successful use of purified recombinant human platelet-derived growth factor in conjunction with autogenous bone, anorganic bovine bone-derived mineral, and a barrier membrane to reconstruct severe alveolar bone defects. Significant horizontal bone regeneration was achieved in the posterior maxillary region. Three implants were placed into the newly formed ridge and demonstrated stable crestal bone after 36 months of loading.

The aim of this study was to evaluate the relationship between gingival translucency and peri-implant mucosa. A total of 22 peri-implant sites in 16 patients who required tooth replacement in the esthetic zone were included. Color measurements were obtained using a spectrophotometer and customized colored abutments. Mucosal thickness measurements were taken incrementally 0.5 mm from the facial gingival margin on sectioned casts. A statistically significant difference in gingival translucency was observed beginning at 1.5 mm. A negative correlation was observed between the thickness and translucency parameter (TP) (r = -0.64), with TP values decreasing as the gingival thickness increased. The gingival translucency was correlated with the thickness of the peri-implant mucosa and distance from the facial gingival margin.

The purpose of this case series was to report the clinical outcomes and histologic findings of vertical ridge augmentation using a combination of titanium mesh, resorbable collagen membrane, and recombinant human plateletderived growth factor BB (rhPDGF-BB). Nineteen patients were included, and autogenous bone and anorganic bovine bone particles were used. The bone graft was mixed with rhPDGF-BB and loaded onto the bony defect up to the level of the adjacent alveolar crest. A pre-adapted titanium mesh was placed over the grafted region and covered with a resorbable collagen membrane, leaving no areas of the grafted region exposed. Seventeen patients exhibited good soft tissue healing. Postoperative flap dehiscence occurred relatively early in the healing period in one patient, whereas the covering collagen membrane was exposed during the later phase of the healing period in another. During reentry surgery for removal of the titanium mesh, three patients with favorable soft and hard tissue healing underwent bone biopsies for histologic evaluation of the augmented tissue just below the titanium mesh. The mean vertical height of augmented bone was 8.6 ± 4.0 mm. This report demonstrates the remarkable efficacy of guided bone regeneration using a combination of titanium mesh, resorbable collagen membrane, and rhPDGF for vertical ridge augmentation, thus expanding the indications for implant therapy and allowing recovery of the three-dimensional esthetic architecture in a severely absorbed alveolar ridge.

An optimal esthetic implant restoration is a combination of a visually pleasing prosthesis and surrounding peri-implant soft tissue architecture. This article introduces a clinical method, the dynamic compression technique, of conditioning soft tissues around bone-level implants with provisional restorations in the esthetic zone. The technique has several goals: to establish an adequate emergence profile; to recreate a balanced mucosa course and level in harmony with the gingiva of the adjacent teeth, including papilla height/width, localization of the mucosal zenith and the tissue profile's triangular shape; as well as to establish an accurate proximal contact area with the adjacent tooth/implant crown.

Dental implants with lengths

The purpose of this study was a histomorphometric comparison of vital bone formation following maxillary sinus augmentation with two different particle sizes of anorganic bovine bone matrix (ABBM). Bilateral sinus floor augmentations were performed in 13 patients. Trephine bone cores were taken from the lateral window areas of 11 patients 6 to 8 months after augmentation for histologic and histomorphometric analysis. Bone samples from both the large and small particle size groups showed evidence of vital bone formation similar to that seen in previous studies, confirming the osteoconductivity of ABBM. Significant bone bridging was seen creating new trabeculae composed of the newly formed bone and residual ABBM particles. Histologic evaluation revealed the newly formed bone to be mostly woven bone with some remodeling to lamellar bone. Osteocytes were seen within the newly formed bone as well as osteoblast seams with recently formed osteoid. Isolated osteoclasts were observed on the ABBM surfaces. Vital bone formation (primary outcome measure) was more extensive in the large particle grafts compared with the small particle grafts (26.77% ± 9.63% vs 18.77% ± 4.74%, respectively). The histologic results reaffirm the osteoconductive ability of ABBM when used as the sole grafting material in maxillary sinus augmentation. The histomorphometric results at 6 to 8 months revealed a statistically significant increase (P = .02) in vital bone formation when the larger particle size was used. Additional studies should be performed to confirm these results.

Autotransplantation is a well-known method used in oral surgery. However, risk of failure, most commonly resulting from root resorption of the transplanted tooth or ankylosis, is quite high. Piezosurgery with specific device tip vibration frequencies enables selective tissue cutting, and therefore, tooth buds or teeth can easily be removed from bones with little injury to periodontal fibers or bud follicles.

The objective of this proof-of-principle multicenter case series was to examine the bone regenerative potential of a newly introduced equine-derived bone mineral matrix (Equimatrix) to provide human sinus augmentation for the purpose of implant placement in the posterior maxilla. There were 10 patients requiring 12 maxillary sinus augmentations enrolled in this study. Histologic results at 6 months demonstrated abundant amounts of vital new bone in intimate contact with residual graft particles. Active bridging between residual graft particles with newly regenerated bone was routinely observed in intact core specimens. A mean value of 23.4% vital bone formation was observed at 6 months. This compared favorably with previous results using xenografts to produce bone in the maxillary sinus for the purpose of dental implant placement. Both the qualitative and quantitative results of this case series suggest comparable bone regenerative results at 6 months to bovine-derived xenografts.

The goal of this case series is to present a novel treatment approach for lateral ridge augmentation. Four systemically healthy patients (aged 48 to 59 years) with inadequate dental alveolar ridge widths were selected for inclusion. All ridge defects were augmented using a xenogeneic cortical bone shield in combination with particulated bone substitutes and a thin collagen barrier. At baseline and after 6 months, digital cone beam computed tomography scans were performed. Biopsy specimens were harvested at reentry surgery and processed for histologic analysis. The results revealed a sufficient amount of bone structure for implant placement without additional augmentation procedures. The histologic analysis demonstrated that new bone formation had taken place and the bone shield had resorbed entirely. This case series indicates that the bone lamina technique has the biologic and mechanical properties to succesfully achieve hard tissue augmentation of deficient ridges.

Resorption of the alveolar ridge may lead to ridge deformities that make dental implant placement difficult or impossible. Augmentation of the alveolar ridge may restore appropriate ridge form to allow implant placement. Forty-four patients with edentulous spaces completed this multicenter prospective trial to clinically and radiographically evaluate the efficacy of a bovine pericardium membrane and a particulate mineralized cancellous bone allograft in promoting lateral ridge augmentation. Overall, 38 of 44 patients (86.4%) were able to receive dental implants in the appropriate restoratively driven position 6 months after ridge augmentation. The mean gain in clinical ridge width after augmentation was 2.61 mm, while radiographically the mean gain in ridge width was 1.65 mm at a level 3 mm apical to the bony crest and 1.93 mm at a level 6 mm apical to the crest. On average, approximately 50% of the graft material added horizontally during surgery was displaced or resorbed during healing. Histomorphometric evaluation of cores taken from the augmented ridge at 6 months revealed that approximately 58% of the tissue volume was vital bone, with 12% residual allograft particles and 30% nonmineralized tissue.

The antral septum, a commonly found anatomical variation, has been related to the occurrence of membrane perforation during sinus augmentation. The aims of this study were to review features of antral septa and to propose a classification system and options for managing antral septa during sinus augmentation. A literature search of the PubMed database was performed to identify articles investigating antral septa. Manuscripts using three-dimensional computed tomography, providing direct measurements of human subjects or cadavers, and reporting features of antral septa besides the prevalence were included. Antral septa presented in approximately 20% to 35% of maxillary sinuses. Single septum was much more common than multiple septa. Mediolaterally (transversely) oriented septa were more frequently found than anteroposteriorly (sagittally) oriented septa. Their size varies and commonly increases from the lateral to medial segment within one septum. The proposed classification consists of three categories-easy (E), moderate (M), and difficult (D)-based on the location, number, orientation, and size of antral septa. Corresponding treatment approaches were suggested for each category. Sinus augmentation is complicated by the presence of antral septa, the features of which determine the degree of surgical difficulty. Based on the results of the included studies and clinical experiences, a classification system and treatment strategies of antral septa were proposed and may assist surgeons in managing antral septa during sinus augmentation.

Intraoral bone grafting is routinely employed for implant site development. Bone graft consolidation is a complex biologic process depending on the formation of blood vessels into the augmented area. Hypoxia-inducible factors (HIFs) and hypoxia-mimicking agents (HMAs) are key stimulators of blood vessel formation. Hypoxia prevents HIFs from degradation, thus signaling angiogenesis. Under normoxia, HMAs prevent degradation of HIFs. The cellular and molecular mechanisms responsible for angiogenic-osteogenic coupling and the therapeutic manipulation of HIFs and HMAs in intraoral bone repair and regeneration are discussed. Such discoveries suggest promising approaches for the development of novel therapies to improve intraoral bone repair and regeneration procedures.

Patients today demand a youthful, attractive smile with comfortable functional acceptance. The complete oral rehabilitation of patients with a functionally compromised dentition frequently involves a multidisciplinary approach and presents a considerable clinical challenge. To a great extent, proper patient selection and careful interdisciplinary treatment planning, including acknowledgment of the patient's perceived needs, reasons for seeking services, financial ability, and socioeconomic profile, can govern the predictability of successful restorations. This clinical report describes a successful interdisciplinary approach for the management of a severely worn dentition with reduced vertical dimension of occlusion. Treatment modalities included periodontal crown lengthening procedures, endodontic treatment followed by post and core restorations, and prosthetic rehabilitation for severe tooth surface loss and reduced vertical dimension of occlusion comprising metal-ceramic restorations in esthetic zones and full-metal restorations in posterior regions.

Patients with insufficient residual alveolar bone height are often treated using short implants. Historically, short implants are associated with higher failure rates. However, recent research has shown short implants with modified surfaces to have success rates similar to those of longer implants. This retrospective report aimed to evaluate clinical outcomes of 8-mm widediameter, moderately rough threaded implants in the posterior maxilla. From June 2008 through May 2010, 16 patients were identified who had been treated with short implants. The mean age of the patients was 50.4 years, the mean primary stability of the implants was 66 ISQ, the mean secondary stability was 75.6, and the mean loading time was 16.2 months. There were no failed implants. The mean marginal bone loss at final follow-up was 0.04 mm. This study exhibited excellent short-term clinical outcomes.

In this case series, a systematic histomorphometric analysis of two human bone biopsy specimens was conducted 1 and 5 years after grafting with a xenogeneic bovine bone substitute material (BSM). While the 1-year specimen still showed extensive signs of an active desmal ossification, the specimen after 5 years mainly showed mature lamellar bone without bone turnover or remodeling. A completed bony integration without extensive resorption of the BSM particles could be detected. Altogether, a good integration in the bone with osteoconduction and a high biocompatibility was seen.

The problem of failed implants cannot be overlooked. The purpose of this paper is to explore treatment alternatives for failed implants and their strengths and shortcomings. A comprehensive literature search was performed using PubMed and a manual search. Only five studies were identified that explored treatment in sites where implants had failed. In all five studies, the treatment alternative tested was the placement of a new implant in the failed site. The overall survival rate for such implants ranged from 71% to 92.3%. Four other alternatives are also discussed in light of data derived from other studies on the survival of various treatment strategies. These include: a continuation of the original plan using the remaining implants, modification of treatment to a tooth-supported fixed partial denture (FPD) or to a hybrid tooth-implant- supported FPD, or modification to a removable prosthesis. The selection of an appropriate alternative for failed implants is complex and involves biologic, mechanical, and psychologic considerations along with financial aspects. This should be a team decision with the patient's opinion included.

This study evaluated the effect of surface treatments on the repair strength of composite resin on a feldspathic ceramic. Ninety ceramic specimens were divided into six groups. In the experimental groups, 4% hydrofluoric acid etching, Er:YAG laser irradiation, CO2 laser irradiation, airborne-particle abrasion, and silica coating were used as surface treatments. After the application of a porcelain repair kit, composite resin was placed on the treated surfaces. After a shear bond strength test, data were statistically analyzed (α = .05). Surface treatments increased the repair bond strength values (P < .05). Airborneparticle abrasion and silica coating were found to be the most effective. CO2 laser showed higher repair strength values than Er:YAG laser.