International Journal of Periodontics & Restorative Dentistry, 03/2003

This human clinical trial evaluated the clinical and histologic response to recombinant human platelet-derived growth factor-BB (rhPDGF-BB) delivered in bone allograft for the treatment of advanced Class II furcation defects. Three mandibular and one maxillary molar furcation defects were treated: Two received 0.5 mg/mL and two received 1.0 mg/mL rhPDGF-BB, in all cases mixed with DFDBA. Clinical probing depths and attachment levels were obtained presurgically and 9 months postsurgical, after which the teeth and surrounding tissues were removed en bloc. Both concentrations of rhPDGF-BB resulted in substantially improved horizontal (mean 3.5 mm) and vertical (mean 4.25 mm) probing depths and attachment levels (mean 3.75 mm). Histologic evaluation revealed periodontal regeneration, including new bone, cementum, and periodontal ligament coronal to the reference notch. Regeneration was also present coronal to the original osseous crest. In one case where an enamel projection extended into the fornix of the furcation, new calcified tissue with new inserting connective tissue fibers was observed over the enamel. This study documented the favorable tissue response to rhPDGF-BB treatment at both the clinical and microscopic levels, provided the first human histologic evidence that new calcified tissue with inserting collagen fibers can occur over enamel projections within furcations, and demonstrated for the first time that complete periodontal regeneration can be achieved in advanced Class II furcation defects using a combination of purified recombinant growth factor and bone allograft.

The present article introduces preliminary clinical and histologic evidence on the combination of a platelet-rich plasma and anorganic bovine bone in maxillary sinus augmentation procedures. The clinical and histologic results from 10 patients underline the different clinical and biologic advantages offered by the combined use of a well-known osteoconductive material, anorganic bovine bone, and a new technique that consists of stimulating bone regeneration using the local increase of growth factors contained in autologous platelet-rich plasma.

Successful treatment of patients requiring complex dental restoration requires a comprehensive evaluation of their existing occlusion. Using a systematic and ordered sequence for relating this occlusion to a physiologic standard greatly facilitates the treatment planning process of reconstruction. Reconstructing the occlusion in this same orderly sequence then significantly enhances the control and predictability of the procedures performed by all practitioners involved in management of the case. Six closely inter-related elements of an occlusion must be evaluated and frequently modified in treatment. Part 1 of this article will discuss two elements of the occlusion, in the order of their evaluation - centric relation position of the mandible and vertical dimension of occlusion.

Simultaneous removal of multiple adjacent teeth in the anterior maxilla often leads to collapse of the labial bony plate as well as flattening of the interproximal bony scallop, resulting in long implant restorations with missing interimplant papillae. An interimplant papilla preservation technique involving alternate immediate implant placement and provisionalization, one following the osseointegration healing period of the other, was introduced. All 14 implants placed in six consecutive patients maintained osseointegration after a mean functioning time of 22.6 months (range 12 to 34 months). A highly satisfactory esthetic outcome and a papilla index score of 3 was observed in all patients.

The zone between plaque and attached periodontal tissues on chronic periodontitis- affected teeth was examined by a combined macroscopic and scanning electron microscopy (SEM) approach. Examined were 27 teeth with chronic periodontitis (chronic periodontitis-affected group) and three healthy teeth with no evidence of periodontal disease (control group). Both groups were collected immediately after extraction, fixed in 2% glutaraldehyde, and post-fixed in 1% osmium tetroxide. Then, teeth were macroscopically examined to identify their stained zones. Teeth were dehydrated, critical-point dried, gold coated, and examined in an SEM. Both healthy and chronic periodontitis-affected teeth showed a very similar staining pattern on their surfaces. An unstained band with a belt-like appearance was observed around the teeth, delimited by two osmium-stained zones. Some weakly stained areas were frequently observed inside the unstained band. The SEM examination showed four different regions in both groups. These regions appeared in the following coronoapical sequence: dental plaque, plaque-free zone, junctional epithelium, and attached periodontal tissues. A dental cuticle covering the cementum surface from the plaque border to the junctional epithelium was detected on chronic periodontitis-affected teeth. Some aspects of this particular zone may be involved in the pathogenesis of inflammatory periodontal disease and therefore may have some influence on treatment for chronic periodontitis- affected teeth.

Currently, most dental implants are placed in the esthetic zone with a delayed surgical protocol. This delay can result in loss of both soft and hard oral tissues following the healing period, necessitating guided tissue regeneration, distraction osteogenesis, or bone expansion and grafting procedures either prior to or at the time of implant placement. If a delayed placement protocol is used, or if grafting procedures are ineffectual, the prosthetic phase of implant dentistry must restore the missing structures artistically and functionally to integrate with the patient's existing dentition. This article presents the option of using a removable implant prosthesis for an esthetic anterior restoration of soft and hard tissues. A computer-assisted camera was used to record speaking, smiling, and active facial positions, with digital imaging to achieve realism for tooth position during the prosthetic phase. The captured patient images with the esthetic setups were transmitted by e-mail for direct viewing by both dentist and dental technician prior to case completion. These images were viewed as reference files during laboratory construction of the prosthesis to achieve the desired esthetic and functional results.

Tooth loss and periodontal disease often leave inadequate alveolar bone volume for simple implant placement. Alveolar bone grafting from an intraoral donor site offers a successful treatment option to regain the original bone volume. The mandibular retromolar area provides a cortical graft that is well-suited for a monocortical or particulated guided tissue regeneration technique and is associated with a low morbidity for the patient. This article describes the technique for easy handling of a bone graft from the mandibular retromolar area and the healing process.

In recent years, dental implant rehabilitation has faced demands from prosthetic and esthetic arenas that call for increasingly ideal outcomes, which require precise surgical planning and placement. Anatomic limitations and bone quantity and quality can now be evaluated using more sophisticated radiographic techniques, although transferring this information to the surgical phase has been at best a difficult task. Recently, computer-aided design and manufacturing have made it possible to use data from computerized tomography to not only plan implant rehabilitation, but also to transfer this information to the surgery. One of these techniques uses stereolithography, a laser-driven polymerization process that fabricates an anatomic model and surgical templates. This novel approach is illustrated with two advanced cases, demonstrating that the technique not only allows for the precise translation of the treatment plan directly to the surgical field, but also offers many significant benefits over traditional procedures.

In severe atrophy of the mandible, implant placement in original bone may not be possible. In this field, augmentation procedures have already been described and controversially discussed. By the use of distraction osteogenesis, bone augmentation without donor morbidity is obtained, while the implant-bone interface remains in original bone. Despite soft tissue expansion during the distraction process, a lack of attached gingiva may cause difficulties at the implant site. In certain cases, an additional soft tissue augmentation procedure has to be performed for a good long-term functional and esthetic rehabilitation. The connective tissue graft and the free gingival graft are recommended to be standard procedures to create a stable periimplant mucosa, but the morbidity and the size limitation of the donor site have to be taken into consideration in selected patients. Transplantation of in vitro-cultured keratinocytes could be an alternative. Distraction osteogenesis and tissue engineering of keratinocytes, as well as bone-cultivating techniques, may increasingly be valuable adjuncts to current augmentation procedures.