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Biomedical subjects

D D Peters

Publications and source records attributed to D D Peters.

At least 19 recordsLinked to original sources
PubMed1994

Adult pulpal diagnosis. I. Evaluation of the positive and negative responses to cold and electrical pulp tests.

This study investigated the positive and negative responses of 1488 teeth in 60 patients to two electric pulp testers and a cold thermal pulp test. Three subgroups of known pulpless or pulpally diseased teeth (teeth receiving root canal therapy, teeth with root canal fillings, or teeth with confirmed associated apical radiolucencies) were identified and their responses evaluated separately. Testing was performed on two tooth surfaces, the facio-occlusal and faciocervical, and on all restorations. The gingival tissue of each patient also was tested using both electrical tests. The primary findings were: (a) teeth not responding to cold and either not responding or responding at readings greater than the tissue response to electrical had a high probability of being in the known pulpless or pulpally diseased subgroups; (b) the only false positive responses to cold in the three subgroups were in multirooted teeth with probable vital tissue remaining in at least one canal; and (c) in the three subgroups, if the false positive responses to electrical that responded at levels higher than the patient's tissue response were considered to be negative responses, the difference in false positives between cold and electrical became not statistically significant (p = 0.07).

Adult↗
PubMed1994

Radiographic determination of canal length direct digital radiography versus conventional radiography.

This research compared the length determination images produced by Trophy and Regam direct digital radiographic systems with conventional E-speed radiographs. Size #15 K files were placed in the canals of 19 teeth of cadaver specimens and radiographed in a geometrically standardized bench device. Three evaluators estimated the length adjustment necessary to position the file at the apex. The mean estimated adjustment lengths were compared with the true, anatomically determined adjustment lengths. Statistical analysis with analysis of variance and the Student-Newman-Keuls test indicated no significant difference between direct digital thermal print images and conventional radiographs (p > 0.10). Length adjustment estimates with conventional radiographs were significantly more accurate than Regam high-resolution computer monitor images (p < 0.01). Additionally, it was determined that length adjustment estimates were significantly more accurate when the file was placed short of the apex (p < 0.001). The clinical relevance of these differences is discussed.

Analysis of Variance↗
PubMed1993

Leakage evaluation with and without vacuum of two gutta-percha fill techniques.

Two sets of 30 roots were obturated either with lateral condensation or a halothane dip technique. Fifteen roots from each group were immersed in India ink with vacuum and 15 without vacuum. Each root was coated with nail polish and wax, leaving only its apical end open for ink penetration. The roots were cleared and three linear measurements were made: distance of ink penetration coronal to the gutta-percha apical tip; distance from the gutta-percha tip to major foramen; and distance from the major foramen to anatomical apex. The average length of ink penetration coronal to the apical extension of the gutta-percha for the lateral condensation groups combined was 1.33 mm and for the halothane groups combined was 2.15 mm. There was no significant difference between vacuumed and not vacuumed for degree of ink penetration. The gutta-percha of the halothane-dipped groups advanced significantly closer to the foramen than the lateral condensation groups (0.38 mm versus 0.65 mm).

Cuspid↗
PubMed1990

Incidence and configuration of canal systems in the mesiobuccal root of maxillary first and second molars.

The anatomy of the mesiobuccal (MB) root of 51 maxillary first and 32 maxillary second molars was studied. Initially, an attempt was made to locate all canals using a standard access and hand instruments. A bur was next used carefully to locate any additional second mesiobuccal (mesiolingual (ML)) canals. Finally, after crown removal, the teeth were reduced horizontally in 1-mm increments and examined by microscope. A second ML canal was located in the coronal half of 95.2% of the roots: by hand instruments in 54.2%; bur in 31.3%; and microscope in 9.6%. There were no root perforations when the bur was used as described. The ML canal orifice averaged 1.82 mm lingual to the MB canal orifice. The difference in incidence of ML canals between the first and second molars was not statistically significant. The canal systems were type 1, 4.8%; type 2, 49.4%, and type 3, 45.8%.

Dental Pulp Cavity↗
PubMed1990

Radiographic evaluation of extruded obturation materials.

The radiographic appearance of filling material extruded into periradicular tissues during obturation of root canals was studied over time. Recall radiographs for up to 6 1/2 yr were compared with immediate postoperative films. Consistently, less material was evident at successive postoperative periods. This study indicated that given time, the two zinc oxide and eugenol-based sealers studied will be removed from periradicular tissues. It also indicated that sealer is removed from periradicular tissues more rapidly than gutta-percha.

Extravasation of Diagnostic and Therapeutic Materi↗
PubMed1984

The comparative efficiency of final endodontic cleansing procedures in removing a radioactive albumin from root canal systems.

Fifty-six teeth were initially instrumented, with the use of seven irrigants or irrigant combinations, and filled with radioactive albumin. The study then showed the relative ability of three final endodontic procedures (copious reirrigation with saline solution, drying with paper points, and reassuring patency of the canal with the final instrument) to remove the albumin. Even after copious irrigation, each additional procedure removed statistically significant amounts of albumin. Alternating an organic solvent and an inorganic solvent did appear to leave the canal system in the optimal condition for final cleansing procedures. The study then correlated the relative efficiency of irrigation alone versus instrumentation plus irrigation in removing the remaining albumin from the canal systems. Reinstrumentation plus copious irrigation removed significantly more albumin than copious irrigation alone.

Chelating Agents↗
PubMed1983

The antibacterial effects of calcium hydroxide apexification pastes on Streptococcus sanguis.

Four calcium hydroxide-based apexification pastes were tested for their antibacterial effects on Streptococcus sanguis. Their zones of growth inhibition on blood agar plates were measured at 2, 4, 6, and 8 days. Only the camphorated parachlorophenol and the metacresylacetate pastes showed zones of inhibition. Both of these zones of inhibition decreased with time; however, the zones of inhibition for the parachlorophenol paste decreased at a slower rate.

Calcium Hydroxide↗