Rajivgandhiuniversity of Health Sciences, Bangalore

RAJIVGANDHIUNIVERSITY OF HEALTH SCIENCES, BANGALORE

KARNATAKA

ANNEXURE – II

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

1. / NAME OF THE CANDIDATE AND ADDRESS (IN BLOCK LETTERS) / Dr.NOUBAD RASHMI SURYAKANTH
POST GRADUATE STUDENT,
DEPARTMENTOF PERIODONTICS & ORAL IMPLANTOLOGY
A.M.E’S DENTAL COLLEGE AND HOSPITAL
BIJENGERE ROAD, RAICHUR-584103
KARNATAKA
.
2. / NAME OF THE
INSTITUTION / A.M.E’S DENTAL COLLEGE, HOSPITAL AND RESEARCH CENTER,
BIJENGERE ROAD, RAICHUR-584103
KARNATAKA.
3. / COURSE OF STUDY AND
SUBJECT / MASTER OF DENTAL SURGERY IN PERIODONTICS AND ORAL IMPLANTOLOGY
4. / DATE OF ADMISSION TO COURSE / 29/07/2013
5. / TITLE OF THE TOPIC / “EVALUATION OF EFFECT OF BACTERIAL ANTAGONISTS AND PROBIOTIC STRAINS ON PERIODONTAL PATHOGENS – A MICROBIOLOGICAL STUDY.”
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8 / BRIEF RESUME OF THE INTENDED WORK :
6.1 Need for the study :
The composition of the oral microbiota is determined by a variety of synergistic interactions, such as food webs & intergeneric coaggregation that facilitate this persistence in a dynamic environment. Likewise interbacterial antagonism is an evolutionary mechanism that aims certain bacterial population against elimination by other microorganisms.
The summation of the antagonistic effects caused by so called beneficial oral microbiota presents a substantial prevention and colonization by exogenous and opportunistic pathogens. Any disruption of this harmonic relationship between host and commensal microorganism is therefore considered as an important factor for the development of oral pathologies, such as tooth decay and periodontal diseases.
Invitro studies have already been performed characterizing potential probiotic bacteria in the oral cavity. Conversely comparison of the commensal species with beneficial properties for periodontal health between healthy and diseased individuals is only sparsely investigated. With the emergence of widespread antibiotic resistance, an alternative for conventional periodontal therapy is necessary. The importance of beneficial commensal bacteria has already been shown with regard to the immune response periodontal colonization. Additionally, the inhibitory effect of some commercial dietary probiotics on periodontopathogens was evaluated and compared with the inhibitory effect of orally derived beneficial bacteria towards a panel of periodontopathogens.
6.2 Review of literature:
Authors compared the prevalence of commensal bacteria with beneficial properties for healthy and diseased individuals. In addition theyexamined the inhibitory effect of some commercial dietary probiotics on periodontopathogens. Tocompare this inhibitory effect to that of orally derived beneficial bacteria,subgingival plaque samples from 35 patients(healthy and periodontitis patients) were analyzed. Growth inhibition of periodontal pathogens Porphyromonas gingivalis (P.gingivalis), Fusobacterium nucleatum (F. nucleatum), and Aggregatibacter actinomycetemcomitans (A.actinomycetemcomitans)were examined using the agar overlay technique and agar well diffusion method. Using the agar overlay technique, it was found that the prevalence of strains antagonistic towards P.gingivalis, Aggregatibacter actinomycetemcomitans was found higher in healthy individuals than in individuals with periodontitis. Compared with the antagonistic activity of the isolated strains, the probiotic strains, overall showed a stronger inhibition of periodontal pathogens.1
An in-vitro study was conducted on lactic acid production by oral streptococcus mitis which inhibits growth of oral Capnocytophaga. Streptococcus mitis strain was isolated from the subgingival plaque of the Insulin Dependent Diabetes Mellitus (IDDM) patient and cultured for use in this study because of its strong inhibitory effect on growth of several oral gram-negative microorganisms. Results showed that strains of Streptococcus mitis inhibited the growth of potential periodontopathic microorganisms such as A.actinomycetemcomitans, Capnocytophaga, species of Bacteriods and Fusobacterium. The present investigation was designed to determine the factors responsible for the inhibitory effect.2
In a study carried to assess the microbial complexes in subgingival plaque, samples were taken from the mesial aspect of each tooth in 185 subjects with or without periodontitis. The presence and levels of 40 subgingival taxa were determined in 13,261plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments were made at 6 sites per tooth at each visit. Similarities between pairs of species were computed using phi coefficients and species clustered using an average unweighted linkage sort. This analysis showed associations among bacterial species as determined by cluster analysis, community ordination and associations among species within complexes .3
A preliminary randomized clinical trial was carried on to find out the effect of the probiotic Lactobacilli reuteri (prodentics) in the management of periodontal disease.Thirty systemically healthy,chronic periodontitis patients were included. Split mouth design was used for scaling and root planing (SRP),which was performed on day 0;two quadrants were treated with SRP whereas remaining two quadrants were left untreated.L.reuteri Prodentis lozenges or the corresponding placebo lozenges were taken from day 21 to day 42.Microbiological levels of the pathogens A.actinomyecetemcomitans,P.gingivalis,and Prevotella intermedia were analyzed. The results showed that Prodentis, either alone or following SRP, reduced A.actinomycetemcomitans, P.gingivalis and P.intermedia levels. The SRP + placebo combination did not significantly affect the pathogens.4
Authors assessed on the effect of periodontal therapy on the number of cariogenic bacteria in different intra-oral niches. 10 patients with severe periodontitis were followed for 8 months after SRP in combination with optimal plaque control.At baseline, 4 months and 8 months,samples were taken from the saliva,dorsum of tongue and supragingival interdental spaces. These samples were cultured both aerobically and anaerobically in order to determine the total number of colony forming units per sample of Streptococcus mutans and Lactobacillus species. Although the total number of aerobic and anaerobic Colony forming units (CFU) in samples from the tongue and the saliva nearly remained constant over the entire observation period, significant increase in the number of Streptococcus mutans could be detected, especially at 8th month. The number of lactobacilli species for different intraoral niches showed only negligible changes, except for the samples from the tooth for which a small, but statistically significant reduction could be detected.5
6.3Objectives of the study :
1.To compare the prevalence of commensal bacteria, for healthy and diseased individuals.
2.To examine the effect of commercially available dietary probiotics with inhibitory effects on periodontal pathogens.
3.To compare the inhibitory effect of commercial dietary probiotics to that of orally derived beneficial bacteria.
MATERIALS AND METHODS :
7.1 Source of data :
Patients of this study will be selected from the outpatient department (OPD) of Periodontics and Oral Implantology, AME’s Dental College and Hospital, Raichur, Karnataka.
7.2. Method of Collection of Data (including sampling procedure, if any) :
Sample Size :
Study sample comprises of 60 patients, of whom 30 will be healthy and 30 diagnosed aschronic periodontitis patients. In these subjects, subgingival plaque samples will be analyzed.
Study period:
The duration of this study will be for 6 months.
Selection criteria:
Inclusion criteria:

Patients within the age group of 30-60 years will be selected.
Patients with chronic periodontitis.
More than 14 teeth with more than 3 teeth in every quadrant.
Turesky plaque index >1

Exclusion criteria:

Prosthesis of any kind.
Medication usage (including antibiotics) prior to 6 months of sample taking.
Antiseptic mouthrinses usage or those who have undergone periodontal therapy within 6 months before sample taking.
Medically compromised patients.
Active oral lesions.
Pregnant and lactating women.
Smokers.

Clinical parameters:
Following clinical parameters will be recorded.
1. Probing depth.
2.Clinical attachment level (CAL).
3. Turesky plaque index.
Investigations:
1. Blood investigations.
2. Orthopantamogram (OPG).
Study Design:
Patients will be divided randomly into the following groups.
1. Experimental group- Consists of subjects with chronic periodontitis.
2. Control group- Systemically healthy subjects.
Clinical examination and sample collection will be performed by single examiner. After baseline examination,plaque samples will be taken from gingival sulcus(healthy subjects) or from apex of the deepest periodontal pocket(patients with chronic periodontitis)in each quadrant. After removing all supragingival plaque by curetting for the sample, it will be transported to the lab in reduced transport fluid until processing. Bacterial isolation procedure will be performed in lab under standard conditions using agar overlay technique and the quantification of the inhibitory mechanism of oral isolates and probiotic strains will be performed with the agar well diffusion method.
Statistical analysis:
Results will be subjected for statistical analysis by following test.
1.The difference in the prevalence of the inhibiting strains among healthy and diseased individuals will be evaluated by performing X2 test.
2.The agreement between the results obtained with the agar overlay technique and the agar well diffusion assay will be evaluated with a Fisher exact test.
7.3 Does the study require any investigations or interventions to be conducted on patients or other humans or animals? If so, please describe briefly.
Yes
7.4Has ethical clearance been obtained from your institution in case of 7.3?
Yes
References:
1. Essche M.V, Loozen G, Godts C, Boon N, Pauwels M, Quirynen M, Teughels W. Bacterial
antagonism against periodontopathogens. J Periodontol 2013;84:801-811.
2. Mashimo P.A, Yamamoto Y, Nakamura M, Reynolds H.S, Genco R.J. Lactic acid production by oralStreptococcus mitis inhibits the growth of oral Capnocytophaga.J Periodontol 1985;56:548-552.
3. Socransky S.S, Haffajee A.D, Cugini M.A, Smith C, Kent R.L Jr. Microbial complexes in
subgingival plaque. J Clin Periodontol 1998;25:134-144.
4. Vivekananda M.R,Vandana K.L,Bhat K.G. Effect of the probiotic Lactobacilli reuteri
(Prodentis) in the management of periodontal disease: a preliminary randomized clinical trial.J.Oral Microbiology 2010;2:5344.
5. Quirynen M, Gizani S, Mongardini C, Declerck D, Vinckier F, Van Steenberghe D. The effect of periodontal therapy on the number of cariogenic bacteria in different intra-oral niches. J Clin Periodontol 1999;26:322-327.