Integration of Dental Implants in Conjunction with EDTA-Conditioned Dentin Grafts: An Experimental Study.

This study was undertaken to investigate the integration of titanium micro-implants installed in conjunction with previously dentin-grafted areas and to study the morphological appearance, mineral content, and healing pattern of xenogenic EDTA-conditioned dentin blocks and granules grafted to cavities in the tibial bone of rabbits. Demineralized and non-demineralized dentin blocks and granules from human premolars were implanted into cavities prepared on the lateral aspects of the tibias of rabbits. After a healing period of six months, micro-implants were installed at each surgical site. Histological examinations were carried out after 24 weeks. Characterization of the EDTA-conditioned dentin blocks was performed by means of light microscopy, dental X-rays, scanning electron microscopy, and energy dispersive X-ray analysis (EDX). No implants were found to be integrated in direct contact with the dentin particles or blocks. On the EDTA-conditioned dentin surface, the organic marker elements C and N dominated, as revealed by EDX. The hydroxyapatite constituents Ca and P were almost absent on the dentin surface. No statistically significant difference was observed between the EDTA-conditioned and non-demineralized dentin, as revealed by BIC and BA. The bone-inductive capacity of the dentin material seemed limited, although demineralization by means of EDTA indicated higher BIC and BA values in conjunction with the installed implants in the area. A 12 h EDTA treatment did not fully decalcify the grafts, as revealed by X-ray analysis.

A Case of an Extensive Keratocystic Odontogenic Tumor in the Mandible Reconstructed with a Custom-Made Total Joint Prosthesis.

The use of virtual surgical planning and computer-aided design/computer-aided manufacturing has previously been reported to enhance the planning for the reconstruction of mandibular continuity defects and to reduce surgical time. Reported is a case of a large keratocystic odontogenic tumor (KOT) affecting right hemimandible including the condylar neck. This case was initially reconstructed with a condyle-bearing reconstruction plate, but because of fatigue fracture 15 years later, a new reconstruction with a custom-made total joint temporomandibular prosthesis was performed.

Reconstruction of nongrowing hemifacial microsomia patient with custom-made unilateral temporomandibular joint total joint prosthesis and orthognathic surgery.

A case of hemifacial microsomia in a young male is presented. The ascending ramus and condyle was reconstructed utilizing virtual 3D planning with a custom-made total TMJ device (TMJ Concepts, USA) in combination with conventional orthognathic surgery. The alternative available reconstructive options are discussed and the advantages and disadvantages of the technique selected.

Demineralized Xenogenic Dentin and Autogenous Bone as Onlay Grafts to Rabbit Tibia.

PURPOSE: The present study was undertaken to evaluate the healing pattern of xenogenic demineralized dentin onlay grafts in comparison with autogenous bone grafts to the rabbit tibia. MATERIAL AND METHODS: Eight 6-month-old New Zealand male rabbits were used in the experiments. Standardized sized dentin blocks from human premolars and similar autogenous bone blocks harvested from tibia were grafted as onlay blocks on each tibia (n = 8 × 2). All animals were killed after a healing period of 12 weeks. RESULTS: Healing was uneventful for all animals. In general, both the dentin and bone block grafts were fused to the bone, resorbed, and replaced by bone and connective tissue to a varying degree. Both types of grafts were still present after 12 weeks, on an average to approximately one third of the original sizes. Resorption cavities could be seen in the dentin with bone formation. Zones of osseous replacement resorption of the dentin could be noted. In both graft types, higher rate of bone formation was seen at the interface between graft and recipient site. CONCLUSION: Demineralized xenogenic dentin onlay grafts showed similar resorption characteristics as autogenous bone onlay grafts, being resorbed in a similar rate during 12 weeks. New bone formation occurred mainly in terms of replacement resorption in the interface between dentin/bone graft and native bone.

Host tissue reactions of non-demineralized autogenic and xenogenic dentin blocks implanted in a non-osteogenic environment. An experimental study in rabbits.

Dentoalveolar ankylosis with osseous replacement is often seen after replantation of avulsed teeth, and this process may be used for preservation of alveolar crests after trauma. Its exact mechanisms with regard to osteoinductive properties are not yet fully understood and need to be systematically investigated. Dentin can possibly act as a slow-releasing carrier of bone morphogenic proteins (BMP), and this property of dentin has been proposed to be used as an alternative or supplement to bone grafting in the maxillofacial region. We aimed to initially asses host tissue reactions to dentin by implanting dentin blocks of autogenic and xenogenic human origin in rabbit connective tissue of the abdominal wall and femoral muscle. Animals were sacrificed after a period of 3 months, and histological processing, sectioning and examinations were carried out. Bone formation, cell counts and thickness of capsule surrounding the grafts were evaluated. Only minor signs of heterotopic bone formation were seen. There were no significant differences between autografts and xenografts or grafts implanted in connective tissue or muscle with regards to tissue reactions except for a significant difference (P = 0.018) in findings of more local inflammatory cells in relation to grafts placed in connective tissue in the autograft group. We conclude that during the time frame of this study, non-demineralized dentin, whether autogenous or xenogenic did not have the potential to induce bone formation when implanted in non-osteogenic areas such as the abdominal wall and abdominal muscle of rabbits.

Short- and long-term changes of condylar position after bilateral sagittal split ramus osteotomy for mandibular advancement in combination with Le Fort I osteotomy evaluated by cone-beam computed tomography.

PURPOSE: Bilateral sagittal split ramus osteotomy (BSSO) may change condylar position, which can be one of the factors contributing to skeletal relapse. This study evaluated short- and long-term changes in condylar position using cone-beam computed tomography (CBCT) and investigated changes in temporomandibular joint (TMJ) signs after BSSO for mandibular advancement in combination with Le Fort I osteotomy. MATERIALS AND METHODS: Thirty-one patients were included, and CBCT data of 62 TMJs were collected before surgery (T0), immediately after surgery (T1), 3 months after surgery (T2), and at the last follow-up at 12.1 ± 3.0 months after surgery (T3). The relation of the condyle to the fossa was evaluated by the method of Pullinger and Hollender (Oral Surg Oral Med Oral Pathol 62:719, 1986). Clinical examination, with a special focus on signs of temporomandibular disorder (TMD), was documented at T0, T2, and T3. Repeated-measures analysis of variance (P = .05) and χ2 test (P = .05) were performed. RESULTS: Data of 27 patients were used for statistical analysis. Values from the formula of Pullinger and Hollender changed significantly with time, but there was no significant difference between the right and left condyles. Condyles moved inferoposteriorly immediately after surgery (T0 to T1) followed by anterosuperior movement 3 months after surgery (T1 to T2). The superimposed effect showed posterosuperior movement compared with the initial position before surgery (T0 to T2) and this position remained stable at 1-year follow-up (T2 to T3). A decrease of TMD signs over time, from 22.6% (T0) to 12.9% (T2) and 9.7% (T3), was observed, which showed no statistical significance. CONCLUSIONS: There were obvious changes in condylar position after BSSO in combination with Le Fort I osteotomy. Condyles tended to be located in a concentric position in relation to the glenoid fossa 3 months after surgery and remained stable during the 1-year follow-up. These changes did not cause an increase of TMD signs.

Rehabilitation of severely resorbed maxillae with zygomatic implants: an evaluation of implant stability, tissue conditions, and patients' opinion before and after treatment.

PURPOSE: The aim of the present study was to describe experiences of 11 consecutively treated patients who received zygomatic implants. Patient results were assessed through clinical and radiographic evaluations of tissue conditions, including resonance frequency analysis (RFA). MATERIALS AND METHODS: Eleven patients were treated with implant-retained fixed prostheses. A total of 64 implants were placed, 22 of which were placed in the zygoma. Fixed prostheses were removed to allow clinical and radiographic evaluations at a follow-up visit 18 to 46 months following implant placement. RFA was performed on all implants. A visual analog scale was used to assess patient satisfaction before and after treatment. RESULTS: All patients received implant-supported prostheses. All zygomatic implants demonstrated clinical signs of osseointegration. One anterior implant was lost during follow-up. Mean ISQ values for the zygomatic and anterior implants were 65.9 (range, 42 to 100) and 61.5 (range, 48 to 71), respectively. Twenty-four implants showed moderate inflammation, with 3 exhibiting severe inflammation. Most anterior implants (75.6%) showed a marginal bone recession of 1 thread or less. Four zygomatic implants showed bone loss of 4 to 5 threads, and 5 zygomatic implants exhibited no marginal bone support. Patients described significant improvement in chewing ability and esthetics but did not describe changes in speech. DISCUSSION: The use of zygomatic implants can help the clinician avoid the need for bone grafting and reduce morbidity. In addition, it can shorten the treatment time considerably. CONCLUSION: This preliminary report demonstrates that zygomatic implants can provide posterior support to fixed prostheses in patients who lack bone volume to place conventional implants without encroaching upon the maxillary sinus.

Fracture of the tibia: complication of bone grafting to the anterior maxilla.

Autogenous tibial cancellous bone has been used for reconstructive operations in oral and maxillofacial surgery for over 10 years, and has reduced many of the problems associated with conventional sites of autogenous grafts such as the iliac crest. The ease of access for harvesting, the speed of the operation, and the abundance of bone, are advantages of this donor site. We report a patient who had a graft taken from the proximal tibia and had a displaced fracture 2 weeks later after a fall. Five similar cases have been reported previously, of which none has required surgical intervention.

Implant stability, tissue conditions, and patient self-evaluation after treatment with osseointegrated implants in the posterior mandible.

BACKGROUND: Implant treatment in the posterior mandible is considered challenging because of bone resorption and the presence of the inferior alveolar nerve, which may result in the use of short implants. PURPOSE: To evaluate implant stability, tissue conditions, and patient opinion after treatment with implant-supported bridges in the posterior mandible. MATERIALS AND METHODS: Thirty-four patients treated with implant-supported bridges in the posterior mandible according to a two-stage protocol were clinically and radiographically examined and interviewed after a mean functional time of 3.9 years. One hundred five Brånemark implants (Nobel Biocare AB, Gothenburg, Sweden) were placed in premolar and molar regions to support 40 bridges. Twenty-eight implants were placed anterior to the mental foramen, and 77 implants were placed posterior to the mental foramen. Bridges were supported either by two or by three implants. After 2 to 6 years, the bridges were removed to analyze the resonance frequency of the implants with the use of a special instrument (Osstell instrument, Integration Diagnostics AB, Gothenburg, Sweden), and an implant stability quotient (ISQ) was recorded for each implant. RESULTS: One implant was lost. An ISQ range of 59 to 90 (mean, 70.05) expressed stability of fully integrated implants in the posterior mandible. Significantly higher (p < .024) ISQ values were found in implants in three-implant bridges when compared with implants in two-implant bridges. There were no differences in ISQ values between molars/premolars, implant types, implant widths, implant lengths, anchoring depth, or uni- or bilateral mandibular bridges. Good mucosal health in the periimplant soft tissue and minor bone resorption around the implants were observed. Patients were generally very satisfied with the treatment outcome. CONCLUSIONS: High implant stability can be reached in the posterior mandible. The implants were more stable in three-implant bridges than in two-implant bridges. The patients were highly satisfied with the treatment, and few complications were seen.

Dental implant treatment in diabetic patients.

The purpose of the present study was twofold: (1) to investigate how many diabetic patients and types of cases that are treated with dental implants in our clinic; and (2) assess the outcome of such treatment. Medical records from 782 patients were examined in patients treated by the Brånemark method for partial or total edentulism with implant supported bridges. From these records, 25 patients (3.2%) with diabetes before implant treatment (136 implants) were identified and further studied with respect to age, gender, type of diabetes, treated jaw, degree of edentulism, bone graft, implant survival, periimplant inflammation, bleeding on probing, and radiographic bone loss. Furthermore, the patients' opinion about the outcome of the treatment was registered. The implant success rate was 96.3% during the healing period and 94.1% 1 year after surgery. Of all 38 bridges, one was lost. Few complications occurred and all patients, except for one, were satisfied with the treatment. Today, diabetic patients are being treated successfully for all types of edentulism, including bone-grafting treatment. Diabetics that undergo dental implant treatment do not encounter a higher failure rate than the normal population, if the diabetics' plasma glucose level is normal or close to normal as assessed by personal interviews.