E. Jeff Burkes

Erbium:YAG (2.94 μm) Laser Effects on Dental Tissues

Past trials with soft and calcified tissues have demonstrated that long pulse train (2.5 mus) Er:YAG (2.94 mum) laser may be used to ablate tooth structure of human teeth. Determination of physical and thermal damage to surrounding tissue during removal of enamel and dentin is a primary objective of this study. Extracted human teeth with thermal probes imbedded in the pulp chambers were submitted to cavity preparation using an Erbium YAG laser with water mist. Wavelength selection as well as use of a water mist during the procedure resulted in efficient tissue removal without significant surrounding damage. Ground sections and SEM sections of teeth showed little or no melting or ash formation in adjacent dentin and enamel and no visible change in the pulp chamber. The surfaces produced by laser ablation were rough and irregular with craters and grooves. Average temperature change in the pulp chamber monitored during tooth preparation was 2.2 degrees Centigrade. These findings suggest that constantly available water aids vaporization and microexplosions, increasing the efficiency of tooth structure removal, and aids in cooling of the tooth structures. The long pulse Er:YAG (2.94 mum) laser may be an effective method for tooth reduction applications when used with a water mist.

Multiple idiopathic root resorption

Abstract Resorption of individual teeth is a common phenomenon, but there are few reported cases of multiple idiopathic root resorption. This article reports progressive root resorption in two female patients. The resorptive process begins in the area of the cementoenamel junction of vital teeth and progressively involves all or nearly all of the teeth. Historical information, clinical laboratory examinations, and histologic study plus a search of the literature have failed to reveal or suggest the etiology of this pathologic condition.

Bone scanning with99mtechnetium phosphate to assess condylar hyperplasia. Report of two cases

Abstract Condylar hyperplasia poses a problem in planning treatment because it is a self-limiting process for some but not all patients. Continued growth creates a progressive deformity that requires condylectomy, whereas an enlarged condyle can be left in place after hyperplastic growth ceases, even if ramus surgery is needed to correct asymmetry. Bone scan with 99m technetium phosphate can be used to assist in making the differential diagnosis. In the two patients reported here, abnormal metabolic activity revealed by bone scans supported clinical and historical evidence that the condylar hyperplasia was active and required surgical correction, including condylectomy. The two cases demonstrate different approaches to postsurgical orthodontic treatment, depending on the amount of normal growth expected.

Amelogenesis imperfecta with taurodontism

Reports of families having a combination of amelogenesis imperfecta and taurodontism are limited. This study of members of three families shows that the combination is inherited as an autosomal dominant trait. In each of the patients examined, neither condition was seen without the other. The enamel was rough and dysplastic and varied in color from white to yellow. Radiographically, taurodontism was present in the deciduous and permanent dentitions. The pulp chambers of the incisor teeth were larger than is usually seen at all ages. All patients had normal-appearing hair, fingernails, and bones. The distinction between amelogenesis imperfecta with taurodontism and the tricho-dento-osseous syndrome is discussed.

Subpontic osseous proliferation

Nine patients, five women and four men, demonstrated bone growth in an edentulous region of the posterior mandible covered with a pontic. The reasons for this bone growth could include genetic predetermination, functional stresses, and chronic irritation. This bone growth has important clinical and basic science implications. The condition was seen only in adults, only in the mandibular posterior region, and with a variety of pontic designs. Subpontic osseous proliferation was documented in nine patients, but no conclusion about the etiology was made.

Blood-flow mapping of oral tissues by laser Doppler flowmetry.

The purpose of this study was to develop a rapid protocol for noninvasive quantification of blood flow at intraoral sites by laser Doppler flowmetry. For each flow measurement, the lowest flow observed over a 30-s period was recorded. Three flow readings at each site were averaged and recorded. Forehead and dorsal right-hand blood flows measured agreed with previous laser Doppler flow measurements. Flows measured with a hand-held probe were not different from flows measured with a stent-stabilized probe on the attached gingiva and an adhesive-stabilized probe on the dorsal hand. High flows were found in the tongue, buccal mucosa, and buccal vestibule. Medium flows were found in the attached gingivae. The lowest flows were found in the teeth. These results indicate that flow in intraoral tissues varies by site and can be noninvasively quantified with the laser Doppler flowmeter when a rigorous measurement protocol is used.

Temporary silastic implantation following discectomy in the primate temporomandibular joint

Silastic (Dow Corning, Midland, MI) has been used in the surgical treatment of a variety of temporomandibular joint (TMJ) disorders as either a permanent or temporary implant. In this study four Macaca fascicularis monkeys underwent bilateral TMJ discectomies and high condylar shaves. The experimental side was treated with a Silastic sheet implant which was removed at 3 months postdiscectomy. The contralateral side was left without an implant and served as a control. Animals were killed at 3, 4, 5, and 6 months postoperatively. A fibrous connective tissue capsule was found around the Silastic implant at all time intervals. This capsule formed a single joint space between the inferior surface of the glenoid fossa and articulating surface of the condyle. Three months following implant removal, the capsule was still present and there was no significant inflammatory cell infiltrate. The severity of the degenerative changes was decreased on the implant side.

Dentin dysplasia II

Dentin dysplasia II is a rare developmental defect of dentin and pulp. It is shown by thistle tube-shaped coronal pulp chambers that contain pulp stones. Often, the root canal is threadlike. This paper describes three patients with this defect. The deciduous teeth are brown and translucent; the permanent teeth have normal coloration with significant pulpal and dentin abnormalities.

Carcinoma arising in the area of median rhomboid glossitis.

Routine soft-tissue examination of a 44-year-old Negro woman who consulted her dentist for a new maxillary partial denture revealed a depressed white lesion in the area of median rhomboid glossitis. Biopsy diagnosis of the area was well-differentiated squamous-cell carcinoma. The relation of this lesion to median rhomboid glossitis is questioned in view of previous reports.