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Biomedical subjects

P B Lockhart

Publications and source records attributed to P B Lockhart.

At least 19 recordsLinked to original sources
PubMed2005

Randomized controlled trial of pilocarpine hydrochloride for the moderation of oral mucositis during autologous blood stem cell transplantation.

Pilocarpine hydrochloride has been reported to increase salivation and decrease oral mucositis in patients receiving head and neck radiotherapy, but there is only one report of its use in a cancer chemotherapy patient population. This prospective, double-blinded, randomized, placebo-controlled trial was undertaken to determine the efficacy of pilocarpine for the moderation of oral mucositis during autologous blood stem cell transplantation. Subjects were randomized to receive a 5 mg tablet of pilocarpine, or a placebo, during and following chemotherapy. Subjects were seen every other day and evaluated for gingival, oral, and oropharyngeal mucositis; nutrition; oral hygiene; eating; speaking; sleeping; pain at rest and/or with swallowing; and mouth dryness. We recorded the mean and highest scores and duration of problems, along with white blood cell counts and differentials, and the use of systemic narcotics for oral mucosal pain. We enrolled and randomized 36 subjects, and there were no statistically or clinically significant differences for the primary outcome of severity of mucositis and no clinically significant differences in any of the other outcome measures. Pilocarpine has no benefit for the moderation of the incidence, severity, or duration of mucositis in patients receiving autologous blood stem cell transplantation.

Adult↗
PubMed2003

Dental management considerations for the patient with an acquired coagulopathy. Part 2: Coagulopathies from drugs.

Dental patients often give a medical history that suggests the possibility of a coagulopathy from drugs, with a corresponding risk for prolonged bleeding during and following an invasive procedure. Identification of patients who may be prone to oral bleeding requires specific medical history information and the proper use of laboratory tests. Some NSAIDs are reported to cause prolonged oral bleeding, but scientific evidence is lacking. Likewise, the risk of oral bleeding from anticoagulants such as warfarin is often over stated, and unnecessary adjustment of NSAID or warfarin dosage puts patients at risk for significant morbidity and mortality. Some commonly employed laboratory tests such as the prothrombin time provide helpful information when used in the appropriate setting, but others, such as the bleeding time test, provide little or no predictive value in the determination of patients at risk for oral bleeding. Dental management of patients with potential coagulopathies from medications requires an understanding of basic principles of coagulation. The vast majority of these patients can be managed in the community setting without risk and without alteration of anticoagulant drug regimes.

Alcohol Drinking↗
PubMed2001

Benzydamine HCl for prophylaxis of radiation-induced oral mucositis: results from a multicenter, randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Benzydamine was evaluated in patients with head and neck carcinoma for treatment of radiation-induced oral mucositis, a frequent complication of radiation therapy (RT) for which there is no predictable therapy or preventive treatment currently available. METHODS: The safety and efficacy of 0.15% benzydamine oral rinse in preventing or decreasing erythema, ulceration, and pain associated with oral mucositis during RT were evaluated in a randomized, placebo-controlled trial conducted in patients with head and neck carcinoma. Subjects were to rinse with 15 mL for 2 minutes, 4-8 times daily before and during RT, and for 2 weeks after completion of RT; study evaluations were conducted before RT and routinely thereafter up to 3 weeks after RT. RESULTS: During conventional RT, regimens up to cumulative doses of 5000 centigrays (cGy) benzydamine (n = 69) significantly (P = 0.006) reduced erythema and ulceration by approximately 30% compared with the placebo (n = 76); greater than 33% of benzydamine subjects remained ulcer free compared with 18% of placebo subjects (P = 0.037), and benzydamine significantly delayed the use of systemic analgesics compared with placebo (P < 0.05). Benzydamine was not effective in subjects (n = 20) receiving accelerated RT doses (> or = 220 cGy/day). The incidence of adverse events between treatment groups was comparable without significant differences. Early discontinuation because of adverse events occurred in 6% of benzydamine subjects and 5% of placebo subjects, and there was 1 death (related to the primary diagnosis) in a placebo subject. CONCLUSIONS: Benzydamine oral rinse was effective, safe, and well tolerated for prophylactic treatment of radiation-induced oral mucositis.

Adult↗
PubMed1999

Oral microflora as a cause of endocarditis and other distant site infections.

Bacteremia originating from the oral cavity is common, but the role of bacteremia in the genesis of infective endocarditis and other distant site infections is unclear. Only a small percentage of oral flora have been associated with distant site infection. Important issues remain unresolved concerning the identification of patients at risk, the relative risk from invasive dental procedures versus naturally occurring bacteremia, and the impact of prophylactic antibiotics on the incidence, nature, magnitude, and duration of bacteremia from the oral cavity. This article addresses the controversies in infection management in patients at risk for distant site infection.

Antibiotic Prophylaxis↗
PubMed1998

Dental factors in the genesis of squamous cell carcinoma of the oral cavity.

This study investigated the role of dental factors in the genesis of squamous cell carcinomas of the oral cavity. 99 newly diagnosed patients with advanced head and neck cancer were evaluated for potential demographic, dental and prosthetic risk factors. Patients with extra-oral malignancies were used as controls in the analysis of dental factors in patients with intra-oral cancers. We performed multiple comparisons of these factors against the primary tumour sites. An analysis of dental and prosthetic factors and patients with intra-oral versus extra-oral tumours revealed no significant differences. However, all 28 intra-oral malignancies arose in areas in contact with teeth and/or appliances. For example, all 10 oral tongue lesions arose on the lateral borders and all six floor of (drop) mouth primary tumours developed at the flange extension of a lower denture. Patients with partial or full dentures had significantly lower node (N) scores than patients without a prosthesis. Although this paper suggests a relationship between dental factors and the genesis of oral squamous cell malignancies, a larger prospective study would be required to achieve definitive data. Patients at risk should be followed carefully for the development of chronic irritation from teeth and appliances.

Adolescent↗
PubMed1997

Motivational factors in the choice of postdoctoral general dentistry programs.

This study explored the importance of various personal and professional factors that may influence choices concerning postdoctoral training in general dentistry. We sent an eighty-one-question survey to all individuals (N = 1,995) who were registered to participate in the Postdoctoral Dental Matching Program (MATCH) and analyzed 599 returned surveys from those applying to GPR and/or AEGD programs. Approximately twenty questions addressed each of four time periods in the application process. Over half of respondents felt that learning more medicine, increasing their speed with dental procedures, gaining confidence in clinical skills, and treating compromised patients were very important. Over one-third of respondents felt that program location, salary and benefits, program philosophy and faculty, and nondental training experiences were very important. Females felt that thirty-five items were more important than did their male counterparts, whereas males indicated that two items were more important. While there were some differences between applicants to AEGD versus GPR programs, there were far more areas where the applicants to each of these programs shared common concerns. The data suggest that the majority of individuals who consider postgraduate general dentistry programs perceive a lack of experience at the predoctoral level relating to clinical dentistry in general and specifically to their understanding of medical principles and managing compromised patients.

Adult↗
PubMed1996

An analysis of bacteremias during dental extractions. A double-blind, placebo-controlled study of chlorhexidine.

BACKGROUND: The literature is unclear concerning the nature and incidence of bacteremias from oral surgical procedures, the relationship of these bacteremias to dental disease, and the preventive benefit of antibacterial mouth rinses. OBJECTIVE: To determine the incidence and nature of bacteremias during single-tooth extractions in adults. METHODS: A double-blind, randomized placebo-controlled study of 70 patients in which the status of dental disease was compared with the incidence and nature of aerobic and anaerobic bacteremias following a single-tooth extraction and the antibacterial effect of rinses with chlorhexidine hydrochloride. Multiple indicators of dental disease were evaluated and recorded before the surgical procedure. Timing of the mouth rinses, the steps in the surgical procedure, and the two blood drawings were controlled for. RESULTS: Thirty-one (94%) of 34 control patients and 62 (89%) of 70 patients overall had blood cultures positive for organisms at either the 1-minute and or 3-minute mark following the initiation of surgery. The majority of cultures yielded gram-positive cocci. Cultures yielded polymicrobial organisms in 17 patients (24%). Although there was a wide range of severity of odontogenic disease, this did not correlate with results of blood cultures. However, there was a statistically significant difference in the incidence of blood cultures positive for organisms at both shorter (<3 minutes, P=.04) and longer (>6 minutes, P=.04) surgery times. There was not statistically significant difference in either the incidence of blood cultures positive for organisms or in the nature of organisms identified between the chlorhexidine and placebo groups. CONCLUSIONS: Single-tooth extraction should be expected to cause a bacteremia regardless of the status of the dentition or periodontium. Mouth rinses with chlorhexidine not significantly alter the number of positive blood cultures or the nature of the organisms at either of the two blood drawings.

Adult↗
PubMed1996

Pilot study of controlled-release pilocarpine in normal subjects.

OBJECTIVES: Current systemic treatments with sialogogues for patients with xerostomia are limited because of minimal efficacy, short duration of activity, or problems with side effects. The purpose of this pilot study was an initial assessment of safety, efficacy, duration of action, multiple dose tolerance, and side effects of a controlled-release formulation of pilocarpine hydrochloride. STUDY DESIGN: Eight healthy hospitalized subjects were given 15 mg of a controlled-release pilocarpine formulation every 12 hours for three doses. Saliva and blood samples were collected at assigned intervals. Repeated measures analysis and paired t tests were used for statistical analyses. RESULTS: A significant (p < 0.05) increase in both parotid and whole saliva output followed all three doses beginning within 1 hour of dosing and lasting over 10 hours. Mean plasma pilocarpine concentration reached a maximum of 8.2 ng/ml at approximately 1 hour after the first dose, 11.5 ng/ml after the third dose, and declined to near baseline (0.06 ng/ml) 24 hours after the final dose. None of the participants showed evidence of adverse effects including complaints of sweating or gastrointestinal discomfort. CONCLUSIONS: A controlled-release formulation of pilocarpine may overcome the therapeutic weaknesses of current pilocarpine preparations by prolonging salivary secretion and reducing undesirable side effects.

Adult↗
PubMed1994

Pretherapy dental status of patients with malignant conditions of the head and neck.

Maxillofacial problems after radiotherapy to this region are common and have at least a temporal relationship to preexisting odontogenic disease. This study was undertaken to determine the dental status of patients before multimodality therapy for head and neck cancer. One hundred thirty-one patients were examined during their initial visit to a head and neck tumor clinic. The majority of dentulous patients were noncompliant with routine dental care (76%) and oral hygiene (65%). There was a high incidence of alveolar bone loss (66%), clinical caries (71%), and failing restorations (91%). Overall, 73 (97%) of the dentulous patients needed dental care before radiotherapy; however, follow-up visits revealed that 59 (81%) of these patients did not seek the indicated treatment. These data suggest that thorough oral examinations should be performed on all patients before radiotherapy that involves the oral cavity.

Adolescent↗
PubMed1994

The program directors' perspective on the goals and objectives of advanced general dentistry training.

In September of 1991, all postgraduate general dentistry (PGD) program directors (Advanced Education in General Dentistry [AEGD] and General Practice Residency [GPR] directors [n = 325]) were surveyed to ascertain their opinions of the ideal goals and objectives of PGD programs. The response rate was 81.5 percent (n = 265). The directors rated the relative importance of various PGD program goals and objectives. The average of all the items rated was 3.4 on a scale ranging from 1 = unimportant to 4 = very important. The respondents identified several clinical and didactic subject areas that they considered very important including; infection control, CPR, dental and medical emergencies, diagnosing dentoalveolar trauma, diagnosing oral pathology, and assessment and treatment of patients with medical conditions. They also identified several training areas which were beyond the scope of a PGD program, e.g., research techniques, pediatric sedation, and selected advanced clinical procedures in dentistry (implantology and orthodontics) which require a long time to complete. In general, there was substantial agreement among the directors of different program types and sites as to the relative importance of various program goals. The largest differences were found among directors of programs from different sites, e.g., hospitals versus dental schools as opposed to directors from different program types, e.g., GPR versus AEGD. There is now a need to determine the relationship of these identified idealized goals and differences to program outcomes for the graduates of PGDs.

Analysis of Variance↗
PubMed1992

Magnetic resonance imaging of human teeth.

There is a need in clinical dentistry for improved diagnostic methods for an accurate evaluation of pulp tissue pathosis. The purpose of this investigation was to attempt to image extracted human teeth with the aim of establishing the possible future application of magnetic resonance imaging in the diagnosis of pulpal pathosis. The results of this pilot study demonstrate that, in the in vitro setting, the outline of the tooth and pulp chamber can be imaged with a high degree of accuracy, and detailed images of the periodontal membrane and gross pulpal anatomy can be obtained. There were obvious differences in the signals given off by different locations within these teeth, and the images of the dental pulp tissue were detailed enough to suggest the possible correlation with histology. The high (9.4 T) field strengths used in this study demonstrate the in vitro application of this technology and the future possibilities for diagnosis of periodontal and odontogenic problems are significant.

Dental Pulp Diseases↗
PubMed1992

Correlation of magnetic resonance image and histology of human teeth.

Current methods for diagnosis of pulpal pathosis are often inadequate and there is a need for an in vivo method to visualize dental pulp tissue. This report compares micromagnetic resonance imaging (MMRI) with routine H & E histology on a cross sectional view of a molar tooth. The extracted tooth was imaged with a Bruker AM-400 NMR spectrometer modified with a microimaging accessory. The tooth was then decalcified and sectioned at the same level as the MMR image. Image intensity readings were acquired for specific areas of the pulp chamber for comparison with histology. The results demonstrate that there is a close correlation between the MMRI and the low power H & E appearance of pulp tissue.

Dental Pulp↗