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Biomedical subjects

H J Keene

Publications and source records attributed to H J Keene.

At least 19 recordsLinked to original sources
PubMed2001

The effects of toothpastes on the residual microbial contamination of toothbrushes.

BACKGROUND: Contaminated toothbrushes have been shown to harbor and transmit viruses and bacteria. The authors conducted a study to evaluate the effect of a triclosan-containing toothpaste on the residual anaerobic microbial contamination of toothbrushes. METHODS: Twenty patients who had Type III or Type IV periodontitis participated in this study. One side of each of their mouths served as a control (no toothpaste). The teeth on the other side were brushed with a regular toothpaste or a triclosan-containing toothpaste. After the toothbrushes were allowed to dry in air for four hours, the authors placed the toothbrush heads in solution, dislodged the microbes from the brushes by vortexing and plated them in culture dishes. The authors anerobically incubated the culture dishes and determined the presence or absence of Prevotella species or Ps; Porphyromonas gingivalis, or Pg; and Actinobacillus actinomycetemcomitans, or Aa. RESULTS: The authors detected Aa and Pg on the control toothbrushes more frequently than they did Ps. This variation in isolation frequency was statistically significant by chi 2 analysis (P < .001). The authors compared the isolation frequency of the three test organisms between the control and regular-toothpaste groups, between the control and triclosan-containing--toothpaste groups, and between the triclosan-containing--toothpaste and regular-toothpaste groups. They found no significant intergroup differences in the isolation frequencies after using chi 2 analysis. CONCLUSIONS: Toothpaste use reduced the residual microbial contamination for two of three test organisms, but the lower isolation frequencies were not statistically significant. Further study in this area is indicated. CLINICAL IMPLICATIONS: Dental professionals should advise patients who have systemic, localized or oral inflammatory diseases to disinfect or frequently replace their toothbrushes.

Aggregatibacter actinomycetemcomitans↗
PubMed2000

Oral health survey of 5-12-year-old children of National Guard employees in Riyadh, Saudi Arabia.

OBJECTIVES: To assess the oral health status, preventive practices and mutans streptococci (MS) levels among the children of National Guard personnel living in Riyadh, Saudi Arabia. DESIGN: Cross-sectional study of schoolchildren. SETTING: Dental Clinic of the National Guard Hospital in Riyadh, Saudi Arabia. SAMPLE AND METHODS: A sample of 272 5-12-year-old children, 154 males and 118 females (95% Bedouin), were selected from approximately 35 National Guard schools in the Riyadh area. An examination was performed in the dental clinic in the National Guard hospital. Oral hygiene was assessed using the Simplified Debris Index (DI-S); Gingival Index (GI) was used to measure gingival health; dental fluorosis was recorded according to the criteria of Dean. Dental caries (dmft, dmfs, DMFT and DMFS) was recorded according to the recommendations of Haugejorden. Concentration of MS in saline rinse samples was assessed by routine laboratory methods and expressed as colony forming units (CFU) per ml (log10). RESULTS: There was a high level of dental caries (mean dmft = 3.8 +/- 3.2; mean dmfs = 21.5 +/- 15.7; mean DMFT = 2.0 +/- 1.9; mean DMFS = 3.1 +/- 3.7). Only 0.7% of the children had no caries experience (dmft + DMFT). MS levels ranged from 0 to 7.5 x 10(5) CFU per ml (mean MS = 4.10 +/- 0.90 log10 CFU per ml). A significant relationship between MS and caries experience was observed (P = 0.003). Mild fluorosis was observed in 14% of the children. Oral hygiene scores indicated that most of the examined tooth surfaces had detectable plaque (mean DI-S = 1.78). Gingivitis was present in 100% of the children and was considered moderate to severe in 14% (mean GI = 1.18). CONCLUSIONS: The study revealed a high level of oral diseases and poor oral hygiene in the study population and a need for therapeutic and preventive measures.

Arabs↗
PubMed1994

Cariogenic microflora in patients with Hodgkin's disease before and after mantle field radiotherapy.

Because mantle field radiotherapy is associated with partial xerostomia in patients with Hodgkin's disease, the purpose of this study was to evaluate their cariogenic microflora before and after completion of radiotherapy. We obtained samples of oral saline solution rinse from 40 patients with Hodgkin's disease before radiotherapy and from 31 patients with Hodgkin's disease who had survived 1 to 24 years after radiotherapy. We also evaluated caries experience and history of fluoride gel use for caries prevention in these patients. Mutans streptococci and lactobacilli levels were significantly higher in the postradiotherapy patients with carious teeth, particularly in those with limited home use of fluoride gels. In the postradiotherapy group, caries parameters were significantly higher (p < 0.05) than in the preradiotherapy group. Within the postradiotherapy group, both caries and microbial parameters tended to be higher in patients who were less compliant about using the recommended 0.4% stannous fluoride "brush-in" technique than in those who used the gel regularly at home. This study indicates that for patients with Hodgkin's disease who receive mantle field irradiation during the management of their disease, a sustained brush-in program with stannous fluoride gel can be of benefit for caries prevention and for limitation of oral levels of cariogenic mutans streptococci.

Adolescent↗
PubMed1993

Clinical correlation of oral-dental findings with radiographs and with total body bone scans.

Bone scans are frequently used to detect osteoblastic areas in bone, including bony metastases in patients with existing tumors. Various dental conditions have been found to cause areas in the jaws to have increased uptake of radiopharmaceuticals. We studied 30 patients with an existing cancer or previous history of cancer with the use of total body bone scans, panoramic radiographs, and dental examinations, and we found no correlation between the intensity of radionuclide uptake in the jaws on the bone scans and the number of teeth in each jaw, the age of the patient, the degree of periodontal disease, or the number of dental pathoses per jaw. The frequency and intensity of positive scan results were related to the presence or absence of intrabony lesions in the jaws. Dental disease therefore does not appear to mask metastatic disease in the jaws; however, when metastasis is suspected, a dental examination with radiographs is recommended.

Adult↗
PubMed1993

Effect of radioactive iodine therapy on salivary flow rates and oral Streptococcus mutans prevalence in patients with thyroid cancer.

Unstimulated and stimulated salivary flow rates, Streptococcus mutans samples, and dental caries data were obtained from 50 patients with thyroid cancer who had received radioactive iodine, I131, from 0.3 to 20 years earlier. The salivary flow rates were compared with a healthy control group, and the S. mutans counts were compared to a group of patients with head and neck cancer who were sampled before radiotherapy. Flow rates were found to be significantly lower in the patients with thyroid cancer, and S. mutans levels were slightly but not significantly higher than the controls. Longitudinal flow rate data taken on four patients, who served as their own controls before and after I131 therapy, indicated a trend in saliva reduction.

Adult↗
PubMed1992

Effects of total body irradiation on salivary gland function and caries-associated oral microflora in bone marrow transplant patients.

Forty-one cancer patients who received chemoradiotherapy conditioning with bone marrow transplantation were examined for changes in salivary gland function and caries-associated oral microflora. Salivary flow rates (stimulated and unstimulated) and Streptococcus mutans levels decreased after pretransplant cytoreductive therapy and posttransplant prophylactic antibiotic therapy. Normal levels returned with time after the patients left the protected environment. Lactobacillus counts were not affected. Chronic graft-versus-host disease did not significantly influence saliva production. Results indicate that irradiation is probably the major factor responsible for the transient xerostomia.

Administration, Topical↗
PubMed1990

Salivary flow rates in patients with head and neck cancer 0.5 to 25 years after radiotherapy.

In this clinical study at the University of Texas M. D. Anderson Cancer Center, unstimulated and stimulated salivary flow rates were obtained from 47 patients with head and neck cancer who had received mantle, unilateral facial, or bilateral facial field radiotherapy from 0.5 to 25 years earlier. The magnitude of salivary flow rate reduction compared with a healthy control group was primarily related to the radiation dosage and the amount of salivary gland tissue included in the irradiated fields. Flow rates were lower for women in all groups, but these differences were not statistically significant.

Adult↗
PubMed1990

Primary reservoirs of Streptococcus mutans and their relationship to caries experience in adults with good oral hygiene.

Primary reservoirs of Streptococcus mutans were identified in a group of 21 adults with intact dentitions and good oral hygiene by obtaining multiple plaque samples from all available tooth surfaces. Routine cultural methods and a rapid plate scoring method employing a 7-point ordinal scale were used to assess S. mutans levels. Oral hygiene status (DI-S) and caries experience (DMFT and DMFS) were determined clinically. Primary S. mutans reservoirs (high scores) were restricted essentially to the posterior interproximal areas and occasionally in the occlusal pits and fissures of partially erupted mandibular third molars. An anterior to posterior gradient of increasing S. mutans scores was observed for interproximal sites. Oral hygiene scores correlated poorly with DMFT, DMFS and the S. mutans scores obtained for different anatomic locations.

Adult↗
PubMed1989

Oral hygiene and the prevalence of oral group D streptococci in medically-physically compromised and periodontal disease patients.

The relationship between oral hygiene and oral Group D streptococcal carrier status was examined in two groups of dental clinic patients. Eighteen medically-physically compromised and 20 periodontitis patients were selected for study. Oral hygiene status was assessed and the prevalence of oral Group D streptococci was determined by sampling the oral cavity with a vigorous 15 second rinse with 5 ml peptone-saline solution. Three ml of each sample was cultured at 40 degrees C in 30 ml of SF broth for 72 hours. Esculin fermenting colonies isolated from the SF broth were characterized biochemically according to standardized procedures and patients were classified as either carriers or non-carriers. Group D streptococci were detected in 27.8% of the medically-physically compromised group and 4.5% of the periodontal disease patients. The mean DI-S score of the medically-physically compromised group was significantly lower than in the periodontal group. Within the medically-physically compromised group, the DI-S means of carriers and non-carriers were not significantly different. The data indicated no important relationship between oral hygiene and the prevalence of oral Group D streptococci in the groups studied.

Adolescent↗
PubMed1988

Preliminary observations on the effect of mantle field radiotherapy on salivary flow rates in patients with Hodgkin's disease.

Changes in stimulated and non-stimulated whole saliva flow rates were measured in 11 Hodgkin's disease patients who received therapeutic doses of radiation to a mantle field at the M. D. Anderson Hospital in Houston, Texas. Salivary flow rates were examined before, during, and after radiotherapy. Mean flow rate reductions of 54% for non-stimulated saliva and 55.7% for paraffin-stimulated saliva were observed post-radiotherapy. Flow rates had not returned to pre-irradiation levels in any of the patients who were observed for two to three months after completion of therapy. Results obtained from this preliminary study indicate that most patients who receive therapeutic doses of radiation to a mantle field experience a significant reduction in salivary output which is manifest during the period of treatment and persists for a period of at least two to three months post-radiotherapy.

Adult↗
PubMed1987

Prevalence of caries-associated microflora after radiotherapy in patients with cancer of the head and neck.

In this clinical study of irradiated head and neck cancer patients at M. D. Anderson Hospital, 68 adult xerostomic patients using different fluoride gels were evaluated for oral levels of Lactobacillus and Streptococcus mutans during the postradiotherapy period, which ranged from 2 months to 20 years. The fluoride groups were compared with a control group consisting of 21 cancer patients who were scheduled to undergo radiotherapy. Lactobacillus levels were significantly elevated in all postradiotherapy groups, irrespective of the type of fluoride gel used. S. mutans levels in the 0.4% SnF2 group were significantly lower than in the 1.0% NaF gel group. The low levels of S. mutans observed in the SnF2 group suggest that this agent may be exerting a downward selective pressure on the microorganism during the postradiotherapy period.

Adult↗
PubMed1986

Dental caries prevalence in early Polynesians from the Hawaiian Islands.

We examined the skeletal remains of 1338 early Hawaiians (preserved in the Bishop Museum, Honolulu) to determine total caries and root surface caries prevalence. Specimens from seven islands were represented in the collection. Estimation of age at death was made by a combination of dental developmental staging for younger individuals and occlusal attrition and/or alveolar bone loss in adults. Museum records were also consulted for age estimation of adults which was primarily based on osteological criteria. The material was divided into six age groups. Predentate infants and edentulous adults were not included. A total of 19,425 teeth was examined. Caries lesions were observed in 462 individuals (34.5%) and 1895 teeth (9.8%). Coronal caries lesions in children and adolescents tended to be small and not particularly destructive of tooth structure. Root surface lesions in young adults were also small but increased progressively in size in the older groups, resulting in pulp exposure and coronal amputation. Although coronal caries was apparently not a significant dental health problem in children and young adults (compared with contemporary Hawaiians), root surface caries was an increasingly important source of tooth morbidity and tooth mortality in the older population groups. This age-related caries pattern was similar for all of the islands.

Adolescent↗
PubMed1982

The morphogenetic triangle: a new conceptual tool for application to problems in dental morphogenesis.

A hypothetical mathematical model of human dental crown height attainment during morphogenesis was developed. The model is based on well-known histologic stages of tooth development from initiation to crown completion, with special emphasis on the dynamics and life-cycle of the cells of the inner enamel epithelium. From three temporal events (P, initiation of proliferation; D, initiation of differentiation; C, crown completion), and crown height (H) measured at the dentino-enamel junction, a morphogenetic triangle PDZ can be constructed where Z = coordinates of H and C at the time of crown completion. The slope of lines PZ and DZ represent average proliferation rate (Rp) and average differentiation rate (Rd) of the inner enamel epithelium, respectively, during crown formation. From data available in the literature, and based on morphogenetic triangle principles, Rp and Rd were calculated for the deciduous and succedaneous dentitions. A strong positive correlation between Rp and Rd was observed throughout the 20-tooth series (r = 0.996); however, Rp and Rd showed moderately strong negative associations with H, P, D, C, and the intervals between PD, PC, and DC. The smaller deciduous tooth in each deciduous:permanent pair was associated with faster Rp and Rd, and shorter intervals between initiation of proliferation, initiation of differentiation, and crown completion. The data generated in this analysis of a hypothetical dentition, while not definitive, provide new insights and a theoretical basis for a broader understanding of the basic mechanisms involved in the attainment of certain tooth dimensions during morphogenesis.

Dental Enamel↗