David L. Koth

Simultaneous Histological Preparation of Bone, Soft Tissue and Implanted Biomaterials for Light Microscopic Observations

Block specimens of formalin fixed bone, soft tissue and endosseous implanted biomaterials can be successfully embedded in polymethyl methacrylate by employing vacuum desiccation during the dehydration steps and refrigeration during the infiltration step. One-hundred-micrometer histological sections can be obtained from the cured polymethyl methacrylate blocks by cutting with a low concentration diamond wafering blade on a Buehler Isomet Circular Low Speed Saw using Buehler Isocut fluid. The sections can be readily stained and details of individual cells studied by light microscopy, thus allowing interpretation of the relationship between biomaterial and surrounding tissues. The advantage of this method is that it allows observations of the entire specimen in situ. The details of the procedure are presented.

Full crown restorations and gingival inflammation in a controlled population

The volume of crevicular fluid around full crown restorations was measured with a Periotron instrument to compare the gingival inflammation between restored and nonrestored teeth in the same patient. Thirty-eight full crown restorations were compared to nonrestored teeth used as controls in 26 patients. Forty-six full crown restorations in 28 patients were also evaluated according to gingival margin placement to determine if there was a difference in inflammation in gingival tissues. The highly motivated patients were selected from a private practice because of their interest and investment in long-term dental health. The results revealed the following findings. 1. Full crown restorations have the potential for causing gingival inflammation. However, they need not be associated with a significant increase in gingival inflammation when placed in the oral environment of a highly motivated patient in a rigid dental recall program. 2. Gingival inflammation surrounding full crown restorations may be controlled regardless of gingival margin placement when the gingiva is healthy, the restorations are adequate, and the patient is in a strict recall program.

The biologic response to the single-crystal sapphire endosteal dental implant: Scanning electron microscopic observations

T he use of endosteal dental implants has increased exponentially over the past decade as clinicians have applied new designs and different types of biomaterials. All materials used for endosteal implants have one region in common: the interface of the biomaterial with the oral mucous membrane as it passes through the soft tissues from bony crypt to the oral cavity. This soft tissue interface is analogous to the natural tooth dentogingival junction and is critical in the longevity of the implant. The purpose of this article is to present observations using scanning electron microscopy (SEM) on the soft tissue-biomaterial interface. For clarification of terminology, this region will be called the “biologic” or “per-perimucosal” seal.

Fabrication of removable stone dies using cemented dowel pins

Proper dowel pin placement in the working cast is important in the fabrication of a cast restoration. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship. A technique is suggested whereby the dowel pin is orientated and cemented after the working cast has been separated from the impression. This procedure produces a working die that has a correctly positioned dowel pin, is stable, and can be repeatedly returned to its original relationship.

A Statistical Analysis of the Clinical Response to the Single-crystal Sapphire Endosseous Dental Implant in Dog Jaws

A statistical analysis was carried out an the clinical evaluatory data gathered from a two-year longitudinal study of the single-crystal sapphire endosteal dental implant in dog jaws. Statistically, the implants behaved either better than control molars (clinically), or in a manner similar to control molars. These data suggest an excellent prognosis for the single-crystal sapphire dental implant.

Scanning Electron Microscopy of Plasma Etched Implant Specimens

Following surface etching of previously processed plastic embedded specimens containing hard and soft tissues and implanted biomaterials with oxygen plasma, the fine structure of the tissues can be examined by scanning electron microscopy. One micrometer plastic orientation sections (with the implant removed in processing) and 110 microns histological sections (with the implant in situ) were examined. Direct comparison can be made between the scanning and histological observations. An examination in situ of oral tissues next to the biomaterial was also made, care being taken to minimize damage to the specimen. The fine structure of intracellular organelles was examined in detail. The method allows consecutive gathering of histological and ultrastructural data from the same plastic embedded specimen.

Articulation of posterior quadrant impressions for cast restorations

The described procedure provides the dentist with a simple articulation method to reduce chair time and consumption of materials while maintaining accuracy and reliability. This uncomplicated technique should be used only when occlusal equilibration is not necessary, when there are vertical stops after tooth preparation, and when the tooth to be prepared is not involved in lateral excursions.

Esthetic feasibility study using a labial index

Abstract A method of obtaining a labial index has been described that allows the dentist to conduct a thorough preoperative feasibility study with little expense to the patient or dentist. The index can be used in pretreatment and postoperative demonstrations to patients and to satisfy third-party requirements.