Browsing by Author "Miller, Chris H."

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    Longitudinal Determination of Mutans Streptococci Strain Differences by Pulsed Field Gel Electorphoresis in Orthodontic Patients
    (1997) Jordan, Christopher N.; LeBlanc, Donald J.; Christen, Arden G.; Hartsfield, James K., Jr.; Miller, Chris H.; Olson, Byron L.
    Results of numerous studies have positively correlated the Dentocult® SM test(Ivoclar Vivadent, Amherst, New York) with conventional plating techniques for the enumeration of mutans streptococci in saliva. However, similar studies have not been conducted on saliva samples collected from patients undergoing orthodontic therapy. The hypotheses to be tested in this study were therefore threefold: first, that the Dentocult system is an accurate and reliable method for the determination of salivary counts of mutans streptococci when used with orthodontic patients; second, that a trend (either a general increase or decrease) in levels of mutans streptococci would be seen in orthodontic patients; and third, that because a new surface is presented due to orthodontic appliances, different strains of mutans streptococci, possibly exogenously acquired, might account for increased levels of mutans streptococci, should an increase be seen. Therefore, isolates of these bacteria obtained before and after therapy were examined by Pulsed Field Gel Electrophoresis (PFGE) for detection of strain differences. Two baseline saliva samples, and a saliva, tooth plaque, and appliance plaque sample at 1,2,3, and 4 months after commencement of full orthodontic banding and bonding were obtained from 26 patients in the Indiana University School of Dentistry graduate orthodontic clinic for bacterial enumeration and PFGE analyses. Dentocult was found to correlate extremely well with conventional plating techniques, utilizing Mitis salivarius agar supplemented with bacitracin (MSB), when salivary levels of mutans streptococci were either extremely high(> 10 6 CFU/ml saliva) (91 % correlation) or quite low ( <10 5 CFU/ml saliva) ( 100% correlation). For salivary levels of mutans streptococci between these limits, the percent agreement was not as substantial (49% correlation). Salivary levels >10 6 CFU/ml saliva of mutans streptococci was used as an indicator of caries risk. An increase in the numbers of patients at risk for the development of dental caries was seen at the 2 month sample collection point. Thereafter, the number of patients at risk decreased, so that at completion of the study, the number of patients at risk for caries development was down to near that observed prior to treatment. Fermentation reactions and PFGE analyses were completed for all baseline saliva samples, and all 4 month saliva, tooth plaque, and appliance plaque samples. Fermentative data indicated that 86/102 (84%) of the samples obtained were Streptococcus mutans, and that there were no Streptococcus sobrinus isolates present. The remaining isolates 14/102 (16%) were not characterized further, and were assumed to be viridans streptococci. Results of PFGE indicated that the same, or no more than two different strains of S. mutans predominated in the saliva and plaque of most of the patients examined.
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    The Effect of Bonded Orthodontic Appliances on Salivary Mutans Streptococci and on Immunoglobulin A Antibody to S. Mutans
    (1997) Wittler, Michelle L.; Gregory, Richard L.; Switalski, Lech M.; Miller, Chris H.; Garetto, Lawrence P.; Shanks, James C.
    The placement of fixed orthodontic appliances creates a number of new retention sites in the oral cavity, which subsequently leads to an increase in the number of cariogenic bacteria, including Streptococcus mutans, during active orthodontic treatment. We hypothesize that the increased prevalence of S. mutans in the saliva of orthodontic patients provides an antigenic challenge to the mucosal immune system, which leads to an elevation of secretory IgA (sIgA) antibodies to S. mutans in saliva. The purpose of this study was to evaluate the change in numbers of salivary mutans streptococci and the concentration of parotid sIgA antibody to S. mutans with the placement of bonded orthodontic appliances. A randomly selected group of 19 patients requiring the placement of orthodontic appliances was tested in this study. Whole and parotid saliva samples were collected three times prior to bonding and four times during bonded appliance therapy over a 30-week period. Whole saliva samples were spiral plated on mitis salivarius sucrose agar and mitis salivarius sucrose bacitracin agar in order to quantify total oral streptococci and mutans streptococci, respectively. Parotid saliva was assayed for IgA antibody to S. mutans using an established ELISA technique. The results demonstrated a significant (p < 0.05) increase in total oral streptococci and mutans streptococci numbers after six months of orthodontic treatment when compared with the baseline values. The level of sIgA to the clinical isolates of S. mutans was also significantly higher six months after the cementation of orthodontic appliances. These elevated numbers of mutans streptococci elicited a mucosa! immune response, which corresponded with a higher concentration of sIgA to S. mutans in the saliva. There was a significant negative correlation (R = -0.22; p = 0.02) between the numbers of mutans streptococci and sIgA antibody levels to the clinical isolates of S. mutans. When the sIgA antibody levels were elevated the numbers of mutans streptococci were lower. These data suggest that sIgA antibody to S. mutans may be a protective mechanism against an elevated level of mutans streptococci caused by the placement of orthodontic appliances. If the mucosal immune response to S. mutans could be enhanced before bonding orthodontic appliances, this could prevent some of the demineralization found adjacent to bands and brackets.