Search PubMed⌕ Search

Biomedical subjects

G K Johnson

Publications and source records attributed to G K Johnson.

At least 73 records · Page 4Linked to original sources
PubMed1987

The effect of inferior alveolar nerve resection on dentin formation.

The purpose of this investigation was to quantitatively evaluate the effects of inferior alveolar nerve resection on dentinal structures of dogs with the use of fluorescent tissue-time markers. After resection of the mandibular right inferior alveolar nerve and an experimental interval of 70 days, dentin formation was determined from serial cross sections through the mandibular canines. Results indicated that denervation did not appear to affect secondary dentin formation in the canine teeth of dogs.

Animals↗
PubMed1987

Endoscopic treatment of biliary duct strictures in sclerosing cholangitis: follow-up assessment of a new therapeutic approach.

Endoscopic sphincterotomy was performed on 10 patients with sclerosing cholangitis to improve biliary tract drainage and to remove bile duct sludge and stones. In addition, Gruentzig-type balloons were placed endoscopically to dilate severe biliary duct strictures in eight of these patients, and endoprostheses were inserted to bridge high grade strictures in three patients. In order to assess the effectiveness of endoscopic treatment, we compared the number of hospitalizations for clinical episodes of cholangitis in this patient group for similar periods of time before and after therapy. Episodes of cholangitis requiring hospitalization decreased from 2.5 +/- 0.4 per patient in the 12 months prior to endoscopic therapy to 0.2 +/- 0.2 episodes per patient in the year following treatment and to 0.33 +/- 0.2 episodes per patient in the additional follow-up period during the second year. Liver function tests have improved significantly over the follow-up period of 19.1 +/- 2.6 months from the time of endoscopic treatment. The serum bilirubin decreased from 6.9 +/- 2.0 mg/dl to 2.7 +/- 1.4 mg/dl; serum alkaline phosphatase decreased from 959 +/- 214 IU to 385 +/- 89 IU; and serum transaminase decreased from 117 +/- 17 IU to 77 +/- 12 IU. Endoscopic treatment appears to be effective in patients with severe sclerosing cholangitis.

Adult↗
PubMed1987

Blood flow and epithelial thickness in different regions of feline oral mucosa and skin.

The relationship between epithelial thickness and blood flow was examined in 6 mucosal and 3 skin regions of the cat. Blood flow to these tissues was determined using the radiolabelled microsphere method. From histologic sections the proportion of the tissue biopsy occupied by epithelium and the average epithelial thickness were calculated. The oral tissues had a significantly higher blood flow than the skin regions (p less than 0.05). In terms of epithelial thickness, the tissues could be divided into 4 groups (p less than 0.05). These were: a) palate; b) gingival regions and dorsum of the tongue; c) lip and buccal mucosa; d) all skin regions. When epithelial thickness was related to blood flow there was a significant positive correlation (p less than 0.005) indicating that a thicker epithelium is associated with a higher blood flow. This finding may reflect the greater metabolic demands of the thicker epithelia.

Animals↗
PubMed1987

The use of sodium bicarbonate and hydrogen peroxide in periodontal therapy: a review.

The comparative benefits from the use of sodium bicarbonate and hydrogen peroxide over the use of a commercial dentifrice in periodontal therapy is controversial. The consensus of the clinical research indicates that application by patients of sodium bicarbonate and hydrogen peroxide offers no advantage over the preestablished, properly performed home oral hygiene procedures. Any improvements in clinical and microbial parameters generally were attributed to scaling and root planing. The studies that have reported beneficial results with sodium bicarbonate and hydrogen peroxide have used additional antimicrobial agents, concomitant professional application of these substances, and scaling and root planing. In one of these reports, inorganic salts and chloramine-T were delivered subgingivally throughout root-planing procedures, in addition to home application of inorganic salts. Most of these patients also received at least one course of systemic tetracycline therapy. Because this study had no control group, it is impossible to determine whether this program is more effective than are other periodontal therapy programs. A more controlled clinical study involving professional application of sodium bicarbonate, sodium chloride, hydrogen peroxide, and povidone-iodine has shown greater gains in clinical attachment and bone mass than has brushing with toothpaste and water. Again, subgingival scaling and root planing were necessary to attain these results. Because multiple topical agents were applied in both of these reports and systemic antimicrobial agents were used by the Keyes group, it is impossible to determine which agent was responsible for the improvements. Further, professional application may be the crucial factor.(ABSTRACT TRUNCATED AT 250 WORDS)

Bicarbonates↗
PubMed1987

Periodontal considerations for overdentures.

Overdentures can offer an alternative to regular dentures with the correct factors. This paper discusses proper abutment selection and preparation coupled with appropriate periodontal maintenance and caries control to assure the success of overdentures.

Dental Abutments↗
PubMed1985

Diagnosis of Eagle's syndrome.

A case of Eagle's syndrome is presented. Although the incidence of styloid process elongation in the population is fairly common, only a small percentage of these patients exhibit symptoms associated with Eagle's syndrome. It is important for the dental practitioner to be aware of this anomaly and to understand its anatomic basis.

Calcinosis↗
PubMed1985

Root planing with interdental papilla reflection and fiber optic illumination.

The complete removal of accretions during closed scaling and root planing in moderate-deep pockets is difficult, presumably due to inadequate mechanical and visual access. The purpose of this study was to evaluate the effect of minimal papilla reflection and illumination with a prototype fiber optic unit on root planing efficiency. Nonmolar teeth with moderate-deep interproximal pockets (greater than 3 mm) in four patients scheduled to receive immediate complete dentures were randomly divided into groups for treatment: Group I--interproximal root planing augmented by papilla reflection and fiber optic illumination (n = 26 surfaces); Group II--interproximal root planing with papilla reflection only (n = 24); Group III--untreated controls (n = 23). Immediately after treatment, the experimental teeth were extracted, stained with toluidine blue and interproximal areas were evaluated for remaining accretions with a microscope-digitizing pad-computer system. Significantly less (P less than 0.01) root surface was covered by deposits in Group I than Group II (0.57 +/- 0.29% vs. 2.42 +/- 0.63%), and both treatment groups had fewer (P less than 0.0005) accretions than untreated controls (57.72 +/- 3.40%). These results suggest that root planing with papilla reflection produces an interproximal surface with few remaining deposits, and fiber optic illumination and transillumination further enhance this effect.

Dental Calculus↗
PubMed1977

Chronic liver disease and acetaminophen.

A 59-year-old female patient with arthritis developed liver function abnormalities while taking therapeutic doses of acetaminophen. Liver biopsy showed evidence of acute and chronic liver damage. Rechallenge with acetaminophen induced abnormal liver functions almost immediately. The patient has been followed for 2 years since that challenge and remains asymptomatic. Biochemical tests of liver function have returned to normal.

Acetaminophen↗