Salivary flow rates measured during radiation therapy in head and neck cancer patients: a pilot study assessing salivary sediment formation.

STATEMENT OF PROBLEM: Xerostomia often occurs in patients being managed for head and neck cancer who receive radiation therapy. Although accurate salivary sampling can be therapeutically important to measure during radiation, sampling errors can occur because of salivary sediments. Determining the impact that salivary sediments have on measured salivary flow rates during radiation is important for management of patients. PURPOSE: The purpose of this study was to assess the magnitude of error associated with the inclusion of nonsalivary components (sediment) in the calculation of whole stimulated saliva flow rates prior to and during radiation therapy (SS and SSR) in patients with head and neck cancer. MATERIAL AND METHODS: Whole paraffin-stimulated saliva was collected in large-mouth centrifuge tubes from 20 patients with head and neck cancer prior to and during the third week of radiation therapy. Gravimetric methods were used to calculate the flow rates at g/5 min. After centrifugation, supernatant saliva was removed and the sediment was oven-dried to remove residual moisture. Sediment weight was subtracted from the original weight of saliva specimens and flow rates were recalculated. Means and standard deviations were determined and flow rate differences before (BC) and after (AC) sediment correction were evaluated statistically with the paired t test (alpha=.05). A nonparametric analysis of the flow rate data with the Wilcoxon matched-pairs signed-ranks test was also used to examine the magnitude and direction of the intrapair (BC-AC) differences (alpha=.05). RESULTS: On average, salivary sediment contributed less than 1% of the total uncorrected weight of saliva prior to radiation therapy. In specimens collected during radiation therapy, sediment contributed an average of 14% of the total uncorrected weight and as high as 95.4% in 1 patient. Sediment percentages were 20% and higher in 4 patients. In the Wilcoxon analysis, 19 out of 20 paired BC and AC flow rates were higher in the BC group in the SS and SSR samples. CONCLUSIONS: The error associated with the inclusion of salivary sediment in the calculation of saliva flow rates prior to radiation treatment was small, but statistically significant. The magnitude of the sediment effect was more pronounced in specimens taken during radiotherapy and was significant, as determined by the Wilcoxon test, but the mean paired differences were not significantly different according to the t test.

Erratum to "Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study".

Radiation-induced xerostomia can result in the rapid onset and progression of dental caries in head and neck cancer patients. Topically applied fluorides have been successfully used to inhibit the formation of dental caries in this population. However, because intensive daily self-application is required, compliance is an issue. The intraoral fluoride-releasing system (IFRS) containing a sodium fluoride core is a newly developed, sustained-release, passive drug delivery system that does not require patient involvement except for periodic replacement, thus reducing the effect of patient compliance on its effectiveness in dental caries prevention. Twenty-two head and neck cancer patients from U. T. M. D. Anderson Cancer Center, with radiation-induced xerostomia, were entered into a pilot study to contrast the daily home use of a 0.4% stannous fluoride-gel-containing tray (control group) to IFRS (study group) with respect to tolerability and adherence, and to obtain information on relative caries preventive efficacy. Participants were stratified on the basis of radiation exposure and randomly assigned to treatment with either IFRS or stannous fluoride gel. Patients in both groups were fitted with two IFRS retainers and also were instructed to use a 1100-ppm fluoride conventional sodium fluoride dentifrice twice daily. The study was conducted as a single-blinded, parallel-cell trial. Pre-existing carious lesions were restored prior to the beginning of the study. The efficacy variable was determined by the mean number of new or recurrent decayed surfaces. Patients were examined for caries 4, 8, 12, 24, 36, and 48 weeks after initiation of treatment. Reports of adverse reactions were based on information volunteered by patients and that were elicited during interviews. At baseline, the resting and stimulated salivary flow rates (g/5min) were significantly greater in the control group than in the study group (p<0.05). Patients in the control group had received significantly more radiation than those in the test group (68Gy vs. 60Gy; p=0.047). No marked differences in follow-up new and recurrent caries were found between the stannous fluoride gel control and IFRS groups during the study period. The rate of new or recurrent carious lesions in the group treated with the fluoride gel was slightly lower than in the IFRS group, based on carious lesions at the baseline examination (Poisson mean number of new or recurrent carious lesions for the control group=0.55 per year vs. 0.83 per year for the study group, p=0.705; odds ratio of the occurrence of any new or recurrent caries during follow-up for control group vs. the study group=0.80; p=0.781). This pilot study revealed that the IFRS was well-tolerated and safe in this study population associated with minimal complications during the duration of this study and was comparable in efficacy to a SnF(2) gel in preventing caries development. The IFRS provided similar rates of control for caries formation to a fluoride-gel-containing tray. The IFRS is designed to release a daily dose of 0.12mg of sodium fluoride, which can be evenly distributed throughout the oral cavity for a single application of 4 months. It would be more convenient than the daily home application of a tray of 0.4% stannous fluoride or 1.1% sodium fluoride gel, and avoids the problem of variable patient compliance.

Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 1: Fluorides.

Radiation-induced xerostomia results in significant changes in the oral cavity particularly oral microbial changes, which include a marked increase in the number of cariogenic organisms, notably Streptococcus mutans and lactobacillus species. This loss of the capacity to secrete saliva creates or promotes the rapid onset and progression of rampant dental caries. In this 2-part series, the benefit of fluoride in reducing caries activity is presented. Part 1 discusses the historical and currently available fluoride preparations and Part 2 presents data of a recently completed trial investigating the benefit of an intraoral sodium fluoride releasing system.

Clinical evaluation of the intraoral fluoride releasing system in radiation-induced xerostomic subjects. Part 2: Phase I study.

Radiation-induced xerostomia can result in the rapid onset and progression of dental caries in head and neck cancer patients. Topically applied fluorides have been successfully used to inhibit the formation of dental caries in this population. However, because intensive daily self-application is required, compliance is an issue. The intraoral fluoride-releasing system (IFRS) containing a sodium fluoride core is a newly developed, sustained-release, passive drug delivery system that does not require patient involvement except for periodic replacement, thus reducing the effect of patient compliance on its effectiveness in dental caries prevention. Twenty-two head and neck cancer patients from U. T. M. D. Anderson Cancer Center, with radiation-induced xerostomia, were entered into a pilot study to contrast the daily home use of a 0.4% stannous fluoride-gel-containing tray (control group) to IFRS (study group) with respect to tolerability and adherence, and to obtain information on relative caries preventive efficacy. Participants were stratified on the basis of radiation exposure and randomly assigned to treatment with either IFRS or stannous fluoride gel. Patients in both groups were fitted with two IFRS retainers and also were instructed to use a 1100-ppm fluoride conventional sodium fluoride dentifrice twice daily. The study was conducted as a single-blinded, parallel-cell trial. Pre-existing carious lesions were restored prior to the beginning of the study. The efficacy variable was determined by the mean number of new or recurrent decayed surfaces. Patients were examined for caries 4, 8, 12, 24, 36, and 48 weeks after initiation of treatment. Reports of adverse reactions were based on information volunteered by patients and that were elicited during interviews. At baseline, the resting and stimulated salivary flow rates (g/5min) were significantly greater in the control group than in the study group (p<0.05). Patients in the control group had received significantly more radiation than those in the test group (68Gy vs. 60Gy; p=0.047). No marked differences in follow-up new and recurrent caries were found between the stannous fluoride gel control and IFRS groups during the study period. The rate of new or recurrent carious lesions in the group treated with the fluoride gel was slightly lower than in the IFRS group, based on carious lesions at the baseline examination (Poisson mean number of new or recurrent carious lesions for the control group=0.55 per year vs. 0.83 per year for the study group, p=0.705; odds ratio of the occurrence of any new or recurrent caries during follow-up for control group vs. the study group=0.80; p=0.781). This pilot study revealed that the IFRS was well-tolerated and safe in this study population associated with minimal complications during the duration of this study and was comparable in efficacy to a SnF(2) gel in preventing caries development. The IFRS provided similar rates of control for caries formation to a fluoride-gel-containing tray. The IFRS is designed to release a daily dose of 0.12mg of sodium fluoride, which can be evenly distributed throughout the oral cavity for a single application of 4 months. It would be more convenient than the daily home application of a tray of 0.4% stannous fluoride or 1.1% sodium fluoride gel, and avoids the problem of variable patient compliance.

Fluoride knowledge and prescription practices among dentists.

The purpose of this study was to assess dentists' knowledge about fluorides as well as their prescription practices. The study population consists of all general and pediatric dentists in Houston, and the sample consists of 360 general and forty-one pediatric dentists. Data were collected with a self-administered mail questionnaire, which consisted of thirteen open-ended and twenty-nine precoded items. After three mailings, the effective response rate was 46.4 percent. Respondents had been in practice on an average of 18.9 +/-6.6 years; the majority were male. More than 75 percent of respondents believed fluoride level in drinking water is an important determinant of fluoride supplement prescription, and 29 percent felt the same about a patient's weight. The correct ages at which to begin (six months) and to discontinue (sixteen years) the fluoride supplements to children were identified by 14.7 and 14.9 percent of the respondents, respectively. Only 6.7 percent of those prescribing fluoride supplements routinely tested the fluoride level in the patient's drinking water. Even though pediatric and general dentists differed in certain items, the two groups did not differ significantly in prescribing fluorides (OR=2.4, 95% CI=0.94, 6.27). Deficiencies and ambiguity in respondents' fluorides knowledge as well as prescription practices indicated a need for educational interventions.

Mutans streptococci in xerostomic cancer patients after pilocarpine therapy: a pilot study.

OBJECTIVES: Opiod- and/or radiation-induced xerostomia in cancer patients is frequently associated with elevated levels of cariogenic mutans streptococci (MS). STUDY DESIGN: In a single-center, single blind 8-week clinical trial at The University of Texas M. D. Anderson Cancer Center, and from an initial sample of 32 patients, we evaluated MS counts in 28 cancer patients receiving chronic analgesic treatment for cancer pain. All patients received escalating doses of pilocarpine (Salagen) tablets, either 2.5 mg to 5 mg or 5 mg to 7.5 mg qid for 6 weeks, followed by placebo qid for a 2-week washout period. Whole resting saliva flow rates (g/5 min) and MS counts were evaluated at pretreatment, 3 weeks, 6 weeks, and 8 weeks. MS samples were obtained by 5-mL saline rinse (15 sec) at each visit prior to sialometry. RESULTS: In 19 patients (59%), MS counts exceeded 10(5) CFU/mL. At the end of the 6-week trial, 96% of patients showed a positive response to pilocarpine following a 30-minute postdosing evaluation (P=.001). MS counts were lower in 17 patients, higher in 6 patients, and nondetectable before and after pilocarpine in 5 patients (P=.03). CONCLUSION: The reduced MS counts associated with improved saliva flow rates following pilocarpine therapy in this short-term pilot study are encouraging, but further investigation in a larger group of patients over a longer study period is indicated.

Effects of an antimicrobial additive to toothbrushes on residual periodontal pathogens.

OBJECTIVE: Previous studies have reported the link between residual microbial contamination of toothbrushes and periodontal diseases. The goal of this pilot study was to evaluate the effects of an antimicrobial additive (Microban) to toothbrushes on residual retention of periodontal pathogens. METHODOLOGY: Twenty patients had one side of their mouths brushed with a toothbrush containing the antimicrobial agent (experimental side), and the other side with a toothbrush containing no agent (control). Toothbrushes were air-dried (25 degrees C) for four or 24 hours. Toothbrush heads were vortexed and cultured for Prevotella species (Ps), Porphyromonas gingivalis (Pg), Actinobacillus actinomycetemcomitans (Aa), and non-specific colony-forming units (NS). The plates were incubated and counted. Means and standard deviations were calculated, and data were analyzed using a series of t-tests (paired and unpaired) and Wilcoxon matched-pairs signed-rank test. RESULTS: No significant inter- or intra-group differences in mean counts were found; however, when four-hour and 24-hour data for Aa, Pg, or NS were combined, experimental counts were lower than controls in 39/50 (78%) of the matched pairs (Wilcoxon signed-rank test p = 0.01). CONCLUSION: Toothbrushes containing the antimicrobial additive showed lower microbial counts than those without, but between-group means were not statistically significant.