George R. App

Periodontal evaluation of two mucoperiosteal flaps used in removing impacted mandibular third molars

This study compared the results of two types of access flap used in removing impacted mandibular third molars. Fifteen patients were given periodontal examinations consisting of measurements of attachment level, level of the gingival margin, and width of the masticatory mucosa at three locations around the mandibular second molars. The examinations were done preoperatively, and two, six, and 12 weeks after removal of the impacted molars. Analyses of variance indicated that there was no significant difference between the two flap techniques and, therefore, the choice of flap technique is one of operator preference. There was a significant decrease in mean sulcus depth at all measured points for either flap technique, indicating a generally healthier condition around mandibular second molars 12 weeks after the surgical removal of mandibular third molars.

Effect of silicate, amalgam, and cast gold on the gingiva☆

Abstract This report verifies the previous findings that silicate and amalgam restorations produce a chronic inflammation of the gingival sulcus epithelium. It also shows that cast gold restorations were well tolerated in the gingival sulcus area. The physical injury of cavity preparation adds another insult to the soft tissues, as demonstrated by the controls. This injury, however, is repaired within 30 days. The inflammation subsides, and the budding epithelial invaginations into the submucosa apparently subside to the normal microscopic anatomy of the dental epithelium. The mechanism of this sequence is well suited for future investigation.

Root Surface Caries in the Molar Teeth of Rice Rats. 1. A Method for Quantitative Scoring

A new system was devised for scoring root surface caries. The roots were divided circumferentially and apically into areas. Each exposed area and any carious involvement was given a score of 1. Root surface caries was expressed, as total areas affected and as a percentage of the exposed root surface.

Root Surface Caries in the Molar Teeth of Rice Rats. II. Quantitation of Lesions Induced by High Sucrose Diet

Weanling rice rats were fed either standard laboratory chow or Diet 2000. The animals were sacrificed at 4, 8, 12, and 15 weeks. There was an increasing amount of exposed root surface and root surface caries with age in the animals fed Diet 2000. There was exposed root surface but no caries in the animals fed laboratory chow.

Mast Cells and Basophils in the Mandibular Alveolar Connective Tissue and Bone Marrow of Germfree Albino Rats

Mast cells and basophils decreased in numbers in older germfree rats. Degranulation of mast cells increased in older animals. It is possible that aging is related to increasing degranulation and the release of pharmacologically active substances such as heparin. The release of heparin might play a role in bone loss.

A Method for Evaluating the Orifice Pressures of Oral Irrigation Devices

The pressures at the orifices of both self-contained and line-pressure oral irrigation devices can be evaluated with unsophisticated equipment. By measuring the height of the jet expelled by the device, the volume rate over a period of several minutes, and the area of the orifice, pressures can be measured with a precision of 2 to 4 psi. The relation between the pressure, P (psi), the density, Q, the volume expelled, V (cm3) in t (seconds), the height, h (cm) of the jet, the area, A (cm2) of the orifice, and the gravitational constant, g (cm sec-2) is