International Journal of Periodontics & Restorative Dentistry, 06/2010

Erosive tooth wear is a serious problem with very costly consequences. Intercepting patients at the initial stages of the disease is critical to avoid significant irreversible damages to their dentition and to benefit from still favorable conditions when it comes to clinical performance of the restorative measures proposed. In this article, a new classification is proposed to quantify the severity of the dental destruction and to guide clinicians and patients in the therapeutic decision-making process. The classification is based on several parameters relevant for both the selection of treatment and the assessment of the prognosis, such as dentin exposure in the palatal tooth contact areas, alterations at the level of the incisal edges, and ultimately, loss of pulp vitality.

Gingival recession is often associated with abrasion in the cervical area with an unidentifiable cementoenamel junction (CEJ). This condition complicates the diagnosis and treatment of gingival recession. The aim of this study was to propose a technique to identify the CEJ level for planning periodontal and restorative treatment of the recession. The CEJ of a contralateral homologous tooth or adjacent teeth was used to replicate the lost CEJ at the treated tooth. Reconstruction of the CEJ using composite resin and a coronally advanced flap, with or without a connective tissue graft, was performed for 25 recessions in 12 patients. After 2 years, 20 defects (80%) showed complete root coverage with a significant recession reduction (2.4 mm, P .0001).

A 53-year-old woman underwent bilateral reconstruction of her severely atrophic posterior mandible using inlay inorganic bovine bone block grafting. Four months later, a bone specimen was taken for histologic evaluation and eight dental implants were placed. These implants were loaded with a provisional prosthesis after another 4 months. When the definitive prosthesis was inserted 8 months postsurgery, all implants were osseointegrated. Histologic analysis showed that the grafted bone was lined with newly formed bone. The results indicate that inorganic bovine bone blocks might serve as an alternative to autogenous grafting for posterior mandibular augmentation using the inlay technique.

The proper management of gingival recession is critical to the establishment of a natural-appearing soft tissue architecture. Subepithelial connective tissue grafts have been considered the "gold standard" but are limited by the availability of palatal donor tissue. Tunnel techniques have improved the esthetic results of connective tissue grafting. Acellular dermal matrices have been successful in the treatment of gingival recession and are not limited by the palatal anatomy. The aim of this report is to describe the application of the tunnel technique, with use of an acellular dermal matrix, in the correction of gingival recession affecting multiple adjacent teeth in the esthetic zone.

The aim of the present experimental study was to evaluate the physiologic bone remodeling in beagle dogs following the placement of small-diameter (3.25 mm) implants in fresh extraction sites. Five 1-year-old beagle dogs that weighed approximately 10 to 13 kg each were used in this study. The third and fourth premolars (P3, P4) were used as experimental teeth, which were hemisected using a fissure bur; the distal roots were removed carefully using forceps. Implants (3.25-mm wide, 10- or 11.5-mm long) were placed in the fresh extraction sockets with the neck of the implant at the level of the buccal bone crest. The dogs were subsequently put to sleep according to the following schedule: one dog 15 days after implant placement, two dogs after 1 month, and the remaining two dogs after 3 months. The distance from the implant shoulder to the bone wall crest was measured at both the buccal and lingual sites. The width of the buccolingual bone crest was measured using a caliper. Assessments were made immediately after root extraction and at 2, 4, and 12 weeks after implant placement. The mean width of the buccolingual bone crest was 4.5 ± 0.5 mm at the time of root extraction. Subsequently, at 2, 4, and 12 weeks after implant placement, the buccolingual bone width was 4.1 ± 0.5 mm, 3.7 ± 0.3 mm, and 3.5 ± 0.7 mm, respectively. Two weeks after implant placement, the lingual bone crest was measured at 0.2 ± 0.3 mm from the implant shoulder, while the buccal bone crest was 0.3 ± 0.3 mm. After 4 weeks of healing, the mean distance from the implant shoulder to the lingual bone crest was 0.1 ± 0.9 mm, compared to 0.4 ± 0.9 mm for the buccal bone crest. After 12 weeks of healing, the bone crest at the lingual sites was -0.3 ± 0.5 mm from the implant shoulder, compared to 0.8 ± 0.3 mm at the buccal sites. The findings from this study show that although vertical bone remodeling was indeed observed, the mean vertical buccal bone resorption was 0.5 mm. It might be suggested, therefore, that the implant position along the lingual wall and the use of implants with a narrow diameter in relation to the extraction socket width play a key role in reducing the rate of vertical bone resorption at the buccal aspect of implants placed in fresh extraction sockets.

The purpose of this study was to evaluate crestal bone loss around 282 two-piece implants with straight (n = 193) and platform-switched (n = 89) abutment connections after placement at various crestal levels. Implants were assigned into two groups according to straight and platform-switched abutment connections. Each group was further subdivided into three groups depending on the location (supracrestal, crestal, or subcrestal) of the implant cervical platform. Linear measurements of bone resorption were made from the implant's platform to the first point of bone-to-implant contact at the time of implant placement and 2 years postrestoration. Data were statistically analyzed. Statistically significant differences were found between subgroups in both straight and platform-switched categories. The only nonstatistically significant difference (P = .341) arose when comparing the supra- and subcrestal locations in the straight abutment connection group. The platform-switched group exhibited significantly less bone loss (P = .046) only in subcrestal locations. The platform-switched concept was not beneficial during the overall comparison, but it was for the subcrestal location of the abutment connection. Crestal placement of the implant-abutment connection resulted in higher marginal bone resorption in both straight and platform-switched abutments.

This case report presents an unusual complication, cervical root resorption, after a conventional connective tissue grafting procedure and tetracycline root conditioning. The recession was 7 mm high, with 0.5 mm of keratinized tissue present, a 2-mm probing depth, and was classified as Miller Class III. The clinical result was satisfactory and 5 mm of root coverage was achieved. However, after 20 months, cervical resorption was diagnosed. It is suggested that tetracycline root conditioning may cause root resorption in long-term evaluations. There is also a possibility of root resorption occurring in 1-year postoperative controls. Other factors will be discussed in relation to this negative clinical result.

Many studies have shown success with implants placed in grafted bone, and there is an emerging desire to simplify the treatment process by placing implants via a flapless approach using navigation or computer-aided design/computerassisted manufacture techniques. This paper reports a preliminary study of laboratory and clinical procedures that may enable flapless implant placement in patients treated previously with extensive onlay grafting of the severely resorbed maxilla, thereby avoiding secondary exposure of the grafted site. Six patients received 39 implants, with a cumulative survival rate of 97.7% over an average of 48.8 months; all prosthetic reconstructions are successful to date.

The purpose of this case report is to describe the treatment of implants placed in fresh extraction sockets and immediately restored in cases of failure. A healthy 58-year-old nonsmoking man was referred for an implant that had lost osseointegration because of infection. The prosthesis showed slight mobility. It was therefore decided to remove the implant and replace it with a new one immediately. Since the patient refused to wear a provisional removable prosthesis, the possibility of applying an immediate loading protocol was discussed. The failed implant was removed carefully and the residual extraction socket was thoroughly debrided. Subsequently, the new implant was placed with a sterile surgical technique, as described by the manufacturer. The inserted implant had a titanium plasma-sprayed surface. Immediately following implant placement and with the patient still under local anesthesia, the initial restorative treatment began. The patient was placed on a strict follow-up regimen until soft tissue healing was complete. Subsequent follow-up examinations were performed after 12 months. At each recall, the patient underwent a thorough clinical and radiographic evaluation. The healing period proceeded smoothly. At the end of the follow-up period, the implant was asymptomatic, immobile, and osseointegrated. No peri-implant bony defects were observed on probing. The results of the present case report seem to suggest that implants placed in fresh extraction sockets and restored immediately might provide a valid treatment option for the treatment of failed implants.