A model to evaluate bone substitutes for immediate implant placement.

A calcified alloplast was evaluated as a gap-filling material around implants placed immediately into fresh extraction sockets. Periodontal measurements and computed tomography scans were obtained to evaluate the clinical effectiveness of the alloplast when compared with demineralized freeze-dried bone. To determine whether this alloplast would be a suitable grafting material, 14 patients were selected to evaluate the extraction socket as a model for routine histologic confirmation of the efficacy and biocompatibility of bone substitutes. The results of this study showed the following: (1) human extraction sockets can be models for the study of bone/implant interaction; (2) the alloplast was well tolerated and demonstrated no inflammation through histologic evaluation of core biopsies; (3) the alloplast was a suitable material when used as a gap-filling graft in sockets around immediately placed implants; and (4) dental computed tomography scans and periodontal measurements around grafted implants 6 months after the procedure provide valuable clinical information about graft healing and osteointegration.

Quantification of growth factor levels using a simplified method of platelet-rich plasma gel preparation.

PURPOSE: This study compared two methods of preparing platelet-rich plasma (PRP) gel and the levels of PDGF and TGFbeta in each preparation. MATERIALS AND METHODS: Platelet-rich plasma gel was prepared by centrifugation and clotted using the ITA gelling agent (Natrex Technologies Inc, Greenville, NC) or by the addition of thrombin and calcium chloride. The levels of platelet-derived growth factor (PDGF) and transforming growth factor beta (TGFbeta) generated by clot formation were assayed by enzyme-linked immunoassay (ELISA). RESULTS: Both methods of preparation yielded PRP gel in less than 30 minutes. However, the ITA preparation did not require thrombin to achieve adequate gel formation. The levels of PDGF and TGFbeta were similar regardless of which method was used for initiation of clot formation. CONCLUSION: Use of ITA for gel preparation is equivalent to using calcium chloride and thrombin, without the need for special equipment and the risk of coagulopathy.

Synovial chondromatosis of the temporomandibular joint with intracranial extension.

An unusual case of synovial chondromatosis of the temporomandibular joint with intracranial extension, which resulted in complete dehiscence of the floor of the middle cranial fossa, is reported. An overview of the current literature and a discussion of the diagnosis and surgical management of synovial chondromatosis are presented.

Hereditary angioedema: case report and review of management.

The classification, pathophysiology, and treatment of angioedema is reviewed. An overview of acquired and hereditary angioedema is presented with an interesting case report that illustrates the importance of recognition and perioperative management of hereditary angioedema to prevent a potentially fatal outcome.

Method to verify the accuracy of model surgery and prediction tracing.

Accuracy of cephalometric tracings and model surgeries is of utmost importance in planning for orthognathic surgery. The technique described allows surgeons to verify position of the models by superimposing a cephalogram of the mounted models over that of the patient. It also reduces the chance of error during actual surgery by placing models in centric relation. Therefore, the possibility of intraoperative complications, and thus longer operating times, is minimized.

Splint therapy for electrical burns of the oral commissure in children.

Electrical burns of the oral cavity are relatively rare; a case is reported here. An acrylic splint fabricated for the patient helped prevent microstomia and the subsequent development of a deformity.

Submandibular space abscess due to Actinobacillus actinomycetemcomitans.

A submandibular space abscess is reported in which a pure culture of Actinobacillus actinomycetemcomitans was identified. The bacterium may often be overlooked as a pathogen due to its slow growth and its requirement for carbon dioxide for primary isolation. As A. actinomycetemcomitans is often resistant to commonly used antibiotics, proper management is based on careful utilization of microbiologic tests and clinical judgement. In this case prompt surgical drainage and appropriate antibiotic therapy resolved the abscess.

Teichoic acid hydrolase activity in soil bacteria (Bacillus subtilis-sporulation-phosphodiesterase-polyamines-concanavalin A).

Bacterial phosphodiesterases have been found that are capable of cleaving the backbone of teichoic acid. Such enzymes have not been reported previously. An aerobic, gram-negative, rod-shaped bacterium producing this activity was detected and isolated by autoradiography of soil suspensions growing on minimal medium containing (32)P-labeled Bacillus subtilis ATCC 6051 cell walls as the sole phosphorus source. Broken-cell preparations are capable of depolymerizing teichoic acids in media of low ionic strength at near-neutral pH values. An active teichoicase is also present in B. subtilis, ATCC 6051 (the Marburg strain), especially in sporulating cultures.