International Journal of Periodontics & Restorative Dentistry, 06/2015

This case report presents the correction of severe alveolar ridge atrophy due to congenital and iatrogenic factors. Implants that compromised the natural adjacent teeth and overall esthetics for this young patient were removed and replaced after significant vertical bone and soft tissue regenerative procedures. A treatment combination of bone graft particles, a nonresorbable membrane, and enamel matrix derivatives was used. Significant and stable improvement in esthetics was achieved 12 months after final prosthetic restoration, demonstrating the ability of such a combined treatment to correct the esthetic deformity, improve the health of the adjacent natural teeth, and allow for successful implant treatment.

Dental occlusal concepts have developed over time, essentially by trial and error. Most have stood the test of observation, and more recently science has verified some of the viewed occlusal successes. The purpose of this article is to examine and distill, in an evidence-based manner, the commonalities that allow practitioners of one occlusal philosophy or another to achieve consistent success. Medline and the Cochrane Collaboration were used to procure relevant articles.

The aim of this study was to histomorphometrically assess the soft tissue anatomy in single gingival recessions (GR) treated with a laterally positioned flap (LPF). Five patients presenting maxillary first molars with GR to the apex of the buccal surface of the mesial-buccal root were invited to take part. The LPF-treated roots were removed en bloc (the root and the soft tissue covering the treated GR) 3 to 4 months postoperatively. Photomicrographs of Mallory trichrome stain sections were taken to allow reassessment of the specimens regarding the longitudinal dimensions of the crevicular/sulcular and junctional epithelia. The use of LPF resulted in new attachment with formation of crevicular epithelium, long junctional epithelium, and some connective tissue, re-establishing the normal anatomical characteristics of the soft tissues covering the previously exposed root.

An adequate flap release is necessary to perform a tension-free suture over an augmented area. This is a fundamental requisite to attain and maintain a reliable biological seal, protecting the graft from bacterial contamination during the healing period. In the posterior mandible, in particular, the use of conventional periosteal incisions is not always sufficient for a proper buccal flap passivation, as they are often limited by anatomical factors. This article reports a series of 76 consecutive cases of vertical guided bone regeneration in the posterior mandible introducing a novel surgical technique to enhance the coronal advancement of the buccal flap in a safe and predictable way.

This article presents the results of evaluating the changes in peri-implant soft tissue dimensions associated with immediate implant placement into anterior postextraction sockets for four treatment groups: no BGPR (no bone graft, no provisional restoration), PR (no bone graft, provisional restoration), BG (bone graft, no provisional restoration), and BGPR (bone graft, provisional restoration). The vertical distance of the peri-implant soft tissue was greater for grafted sites than for nongrafted ones (2.72 mm vs 2.29 mm, P < .06). The facial soft tissue thickness at the gingival third also was greater for grafted than for nongrafted sites (2.90 mm vs 2.28 mm, P < .008) and for sites with provisional restorations compared to sites without them (2.81 mm vs 2.37 mm, P < .06), respectively. The net gain in soft tissue height and thickness was about 1 mm. The increases in vertical and horizontal dimensions for grafted sites were between 0.5 and 1.0 mm, as compared to sites with no bone graft and no provisional restoration.

The prevalence of gingival recession has been estimated at around 22.5% in people aged older than 29 years. Classic treatment approaches include the use of connective tissue grafts in combination with coronally advanced flaps (CAFs). To reduce morbidity and the need for a secondary surgical site, allograft materials are currently being used. Nevertheless, long-term randomized studies testing the efficacy of these materials are lacking. Hence, the aim of the present randomized controlled clinical trial was to compare two acellular dermal matrix (ADM) materials produced by different processing techniques, freeze-dried (FDADM) and solvent-dehydrated ADM (SDADM). At 12 months, both groups showed significant improvement in attachment level, recession depth, and recession width. A mean imrprovement in attachment level of 2.0 ± 1.08 mm for FDADM and 2.0 ± 0.70 mm for both SDADM was achieved (P = .002). Root coverage after 12 months was 80.66 ± 22.90% for FDADM and 80.97 ± 18.08% for SDADM. Hence, it was concluded that both FDADM and SDADM grafting materials can successfully achieve root coverage in Miller Class I and II recession defects for up to 12 months when used in combination with CAFs.

The goal of this preclinical investigation was to evaluate the healing of tapered roughened surfaced dental implants that were delivered by either a manual torque limiting wrench or an electronically controlled torque limiting device. Three canines underwent bilateral extraction of third and fourth premolars and first molar. The extraction sites were allowed to heal for 2 months before two dental implants were placed bilaterally. All animals underwent a normal healing process. One animal was sacrificed at 1 month and the remaining two animals were sacrificed at 2 months to perform histologic evaluations including bone-to-implant contact (BIC) and soft tissue healing. The clinical stability and histologic osseointegration were similar when the results obtained with the manual torque limiting wrench were compared to those delivered by the electronically controlled torque limiting device. However, BIC and maintenance of the crestal bone level achieved appeared to be higher in the electronically controlled torque limiting device groups.

This study compared the clinical outcomes of recombinant human plateletderived growth factor BB and beta-tricalcium phosphate (rhPDGF-BB/βTCP) with guided bone regeneration (GBR) in immediate implant placement in molar extraction sockets with buccal bone defects versus conventional implant placement. Twenty-eight implants were placed in fourteen patients. Clinical and radiographic evaluations assessed peri-implant soft and hard tissue parameters after 12 months. No implants were lost during the 1-year observation period, yielding a survival rate of 100%. Similar clinical and radiographic parameters were observed for both treatment groups. Use of rhPDGF-BB/βTCP and GBR in immediate implants in molars was as successful as conventional implant placement in fully healed extraction sites.

The aim of this study was to present in detail the clinical steps of the rootmembrane technique. This technique combines the benefits of conventional root submergence via intentional maintenance of a root fragment for ridge preservation with those of immediate implant placement for functional rehabilitation of the treated site. A case study of a tooth diagnosed with a horizontal root fracture is used to illustrate this technique step by step. The clinical application of the root-membrane technique not only allowed for immediate placement in a site with compromised buccal plate but also facilitated excellent clinical stability of soft tissue contours during the 3 years of follow-up.

This study used a two-parameter Weibull analysis for evaluation of the lifespan of fully or partially porcelain-/glaze-veneered zirconia crowns after fatigue test. A sample of 60 first molars were selected and prepared for full-coverage crowns with three different designs (n = 20): traditional (crowns with zirconia framework covered with feldspathic porcelain), modified (crowns partially covered with veneering porcelain), and monolithic (full-contour zirconia crowns). All specimens were treated with a glaze layer. Specimens were subjected to mechanical cycling (100 N, 3 Hz) with a piston with a hemispherical tip (Ø = 6 mm) until the specimens failed or up to 2 × 106 cycles. Every 500,000 cycles, the fatigue tests were interrupted and stereomicroscopy (10×) was used to inspect the specimens for damage. The authors performed Weibull analysis of interval data to calculate the number of failures in each interval. The types and numbers of failures according to the groups were: cracking (13 traditional, 6 modified) and chipping (4 traditional) of the feldspathic porcelain, followed by delamination (1 traditional) at the veneer/core interface and debonding (2 monolithic) at the cementation interface. Weibull parameters (β, scale; η, shape), with a two-sided confidence interval of 95%, were: traditional-1.25 and 0.9 × 106 cycles; modified-0.58 and 11.7 × 106 cycles; and monolithic-1.05 and 16.5 × 106 cycles. Traditional crowns showed greater susceptibility to fatigue, the modified group presented higher propensity to early failures, and the monolithic group showed no susceptibility to fatigue. The modified and monolithic groups presented the highest number of crowns with no failures after the fatigue test. The three crown designs presented significantly different behaviors under fatigue. The modified and monolithic groups presented less probability of failure after 2 ×106 cycles.

In this study, the process of osseointegration on titanium implant surfaces with different physicochemical treatments subjected to a simulated corporal fluid submersion was evaluated using the concept of fractal dimension. It was found that different treatments led to rather different calcium phosphate crystal growth patterns, with fractal dimension ranging from 1.68 to 1.93. The observed crystal patterns may be explained by a general deposition, diffusion, and aggregation growth mechanism, where diffusing particle sticking probability plays a fundamental role.

This article presents the results of a consecutive case series of 170 treated periimplantitis- affected implants in 100 patients with follow-up measurements from 2 to 10 years. A total of 51 implants in 38 patients previously reported on were followed for an additional 2.5 years, and 119 additional implants in 62 additional patients were treated with the same protocol and monitored for at least 2 years posttreatment. The treatment consisted of flap reflection, surface decontamination, use of enamel matrix derivative (EMD) or platelet-derived growth factor (PDGF), and guided bone regeneration with mineralized freezedried bone and/or anorganic bovine bone combined with PDGF or EMD and covered with an absorbable membrane and/or subepithelial connective tissue graft. Maintenance and monitoring followed every 2 to 3 months. Two implants were lost 6 months posttreatment, for a 98.8% survival rate. Bleeding on probing was eliminated in 91% of the treated implants. Probing depth reduction averaged 5.10 mm, bone level gain averaged 1.77 mm, and soft tissue marginal gain averaged 0.52 mm. These outcomes were obtained with one surgical procedure on 140 implants, with two procedures on 18 implants, and with three procedures on 10 implants. The results to date with this layered/combined regenerative approach for the treatment of peri-implantitis appear to be encouraging.

The purpose of the present prospective randomized study was to evaluate the influence of Laser-Lok microtextured surface on soft tissue peri-implant parameters and esthetics around immediate, functionally loaded implants for single-tooth replacement in the esthetic zone. This study included 77 patients divided into two groups based on different implants used: the control group had BioHorizons tapered internal non-Laser-Lok-type implants (NLL; n = 39) and the test group had BioHorizons tapered internal Laser-Lok-type implants (LL; n = 39). Outcome measures were survival, radiographic marginal bone- level changes, soft tissue parameters, and esthetics. One implant was lost in the test group and one in the control group, for a total survival rate of 96.1% after 3 years. Radiographically, mean crestal bone loss ± standard deviation was 0.59 ± 0.27 mm in the LL group compared with 1.17 ± 0.31 mm in the NLL group. A mean gain in papilla level of 0.41 ± 0.34 mm and 0.17 ± 0.36 mm was observed in the LL and the NLL groups, respectively, while the level of the midfacial peri-implant mucosa remained stable in both groups with no statistically significant differences (0.08 ± 0.42 mm for the LL group vs 0.06 ± 0.36 mm for the NLL group). The mean probing depth values in the LL and NLL groups were 0.58 ± 0.2 mm and 1.89 ± 0.3 mm, respectively. Within the limitations of this study, it was demonstrated that the clinical and esthetic outcome of immediate functional loading was more favorable for LL implants than for NLL implants.

Ridge preservation in the esthetic area is still a challenging procedure. The aim of the present case series was to introduce a technique for postextraction socket seal surgery using an epithelized connective tissue graft and socket filling with a xenogeneic biomaterial. Using a tunneling approach, the buccal gingiva and interdental papillae are undermined and augmented with the soft tissue graft. This method was applied and evaluated in 16 sites in 13 patients with need for extraction of at least one maxillary anterior tooth. Five months postoperative, the mean reduction of the horizontal width of the alveolar ridge was 0.5 mm, while the height of the mesial and distal papillae were reduced by 0.2 mm and 0.4 mm, respectively. The buccogingival margin of the alveolar ridge showed a vertical gain of 0.5 mm. Therefore, the presented technique seems appropriate for preservation of the alveolar ridge in esthetically relevant areas.

Passive fit between prosthesis and implants or abutments is a significant factor in preventing mechanical and biologic failures of implant-supported prostheses. Therefore, impression techniques must transfer the 3D implant position as accurately as possible for a correct superstructure fabrication. A novel impression protocol that uses an individualized open tray design is proposed. It allows the clinician to splint the transfers between the copings, outside the impression area, and to the tray itself to create a rigid monoblock. Thus, distortions produced by the tear of impression material or by transfer abutments' micromovements during tray retrieval are limited and superstructure misfits are minimized. This technique is specifically recommended for long spanning or completely edentulous patients.

The success of flapless immediate implant placement is dependent on the bony architecture on the buccal aspect of the socket. The presence of a fenestration defect in the buccal cortical plate may jeopardize the esthetic outcome, especially if the clinician does not undertake adequate soft and hard tissue augmentation procedures. This article describes the use of an esthetic buccal flap design to deal with fenestration defects created during anterior implant placement immediately after extraction. This technique has been proven effective in maintaining the soft tissue architecture and allows hard tissue grafting of the fenestration defect around the implant in a postextraction socket.

Dental agenesis is the most commonly encountered dental anomaly in humans. Oligodontia, however, is a rare condition that involves the congenital absence of six or more teeth, excluding the third molars. Treatment of oligodontia requires an interdisciplinary approach. The prosthetic treatment plan should carefully consider esthetic and functional rehabilitation but should take a conservative approach. Adhesive techniques, combined with the new ceramic materials, permit functional and esthetic prosthetic restorations that are more conservative in comparison to those used in the past. Ultrathin occlusal veneers without tooth preparations may represent a good esthetic and conservative approach for oral rehabilitation of patients affected by severe hypodontia.