Sandra Handler

Effect of Radiation-Induced Xerostomia on Human Oral Microflora

A longitudinal study was performed to assess the effects of radiation-induced xerostomia on the human oral microflora. Pronounced microbial population shifts were found in each of five intraoral sites tested. Cariogenic microorganisms gained prominence at the expense of noncariogenic microorganisms in concert with the saliva shutdown. These changes occurred before the onset of clinical caries irrespective of whether or not a topical fluoride gel was used as a caries preventive.

Radiation‐induced xerostomia in cancer patients. Effect on salivary and serum electrolytes

Saliva and serum electrolyte concentrations were monitored in 30 patients given a course of xerostomia‐producing cancer radiotherapy. The mean flow rate of stimulated whole saliva decreased 83.3% during a 6‐week treatment period. The striking reduction in saliva output was accompanied by significant increases in saliva Na+, Cl−, Ca++, Mg++ and Prot.− concentrations and by a decrease in saliva HCO  3− content. The xerostomic saliva was more concentrated and had a greater salinity than the pretreatment saliva in each instance. In contrast, none of the serum electrolytes measured was significantly altered by the subtotal salivary shutdown.

Interrelations of Oral Microorganisms, Immunoglobulins, and Dental Caries Following Radiotherapy

Of 42 head and neck cancer patients with radiotherapy-induced xerostomia, 36 survived to permit a postirradiation caries evaluation. Twenty-three developed an average of 17.6 caries lesions and 13 had no new lesions within 30 months postirradiation. All caries-inactive patients had been initially assigned to daily self-application of a 1% sodium fluoride gel. The preirradiation caries experience and the oral microbial profile were comparable in both groups. After tumoricidal irradiation, the mean plaque increase of Streptococcus mutans was 25 times greater in the caries-active than in the caries-inactive group. Postirradiation caries was also associated with increased plaque Lactobacillus sp, Candida sp, and Streptococcus sp, and serum IgD and IgG concentrations. Conversely, plaque Staphylococcus sp, Streptococcus salivarius, and Veillonella sp and saliva IgA concentrations were significantly higher in the caries-inactive than in the caries-active group. Both groups demonstrated decreases in plaque Streptococcus sanguis, Neisseria sp, Fusobacterium sp, and Bacteroides sp.

Comparison of the Plaque Microflora in Immunodeficient and Immunocompetent Dental Patients

The nature and extent of the immune dysfunctions in 20 immunodeficient patients, as well as the immunocompetence of 22 control subjects, were verified by cell-mediated responsiveness and immunoglobulin quantitations. Comparisons of the microbial composition of supragingival plaque between the two populations showed that a greater number of immunodefcient than control subjects harbored Candida sp. and Staphylococcus sp. Conversely, a lower number of immunodeficient than control subjects harbored Streptococcus mutans. Also, patients with immune dysfunctions had a lower dental caries experience than their immunocompetent counterparts.

Streptococcus mutans approximal plaque index as a new epidemiologic tool for defining the parameters of Streptococcus mutans infection in human populations

Abstract The clinical, laboratory and statistical methods associated with development of a new plaque index (SMAPPI) which estimates the magnitude of Strep, mutons infection in human subjects from 10 samples per person, are described. A simplified index (SMAPPI-S) is based on 5 samples per person. The partial-mouth indexes correlated strongly with data obtained from whole-mouth sampling and showed a high degree of reproducibility over a 1–4 week sampling period. Intra-examiner and inter-examiner calibration experiments indicated an acceptable level of reliability in laboratory scoring procedures. The individual site scores, graded on an ordinal scale, permitted the use of non-parametric statistical tests. SMAPPI and SMAPPI-S, which are derived by summing the individual site scores, showed a tendency to be distributed normally, indicating their appropriateness to standard parametric statistical procedures.

Effect of Sodium Fluoride on the Viability and Growth of Streptococcus mutans

A fluoride-sensitive (FS) strain of Streptococcus mutans and a laboratory-induced fluoride-resistant (FR) offspring were compared for the effects of sodium fluoride on viability and growth. There was a significant fluoride-related loss of viability in resting cell suspensions of the FS strain during a 47-hour exposure to fluoride levels above 75 ppm that was not encountered with the FR strain. The addition of 300 ppmF to actively growing six-hour broth cultures almost totally arrested the growth of the FS strain, while only slightly reducing that of the FR culture. The addition of 600 ppmF immediately terminated FS growth, and greatly reduced the rate and maximum growth of FR cultures.

Oral Microbial Profile of the Marmoset

Qualitative and quantitative assessments were made of the cultivable oral microflora of adult marmosets that were given three difjerent dietary regimens. The identifiable isolates were dispersed among 12 recognized microbial families, 24 genera, and more than 40 species. Generally, marmosets that received a high sucrose diet had the highest bacterial counts.

Effects of a simulated spacecraft environment on the oral microflora of nonhuman primates

Abstract As part of a program to determine the personal oral hygiene requirements for extended space missions, adult marmosets were maintained in a hypobaric chamber with an atmosphere of 70 per cent O 2 and 30 per cent N 2 at 5 p.s.i. for periods up to 56 days. The marmoset oral microflora was monitored immediately before, during, and after repeated chamber trials. The marmosets adjusted to the space-simulated environment with relatively few problems, except for loss of weight and diarrhea. There were no apparent environment-associated oral tissue changes, qualitative microbial changes, or oral transmission of microorganisms between pairs of chamberhoused animals. There were, however, environment-associated quantitative microbial changes which were animal-related and which were inconsistent with regard to type of microorganism, type of oral specimen, and duration of chamber exposure.

Relationship Between Saliva and Serum Agglutination Titers and Post-irradiation Caries Activity in Cancer Patients

Agglutination titers in 444 saliva and 481 serum samples from 36 head and neck cancer patients and 16 control subjects were determined against formalinized cellular antigens of Streptococcus and Lactobacillus species. Saliva agglutination titers were significantly higher in cancer patients before radiotherapy than in control subjects. Changes in specific saliva agglutination titers to oral isolates following radiotherapy reflected changes in saliva IgA and post-irradiation caries activity. Patients with no post-irradiation caries activity had significantly higher saliva agglutination titers to S. mutans, S. sanguis, and L. fermenti, lower plaque S. mutans counts, and higher saliva IgA levels than those with post-irradiation caries activity. Serum agglutination titers were unrelated to either serum immunoglobulin levels, microbial counts, or caries activity.