RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE, KARNATAKA.
ANNEXURE – II
SYNOPSIS FOR REGISTRATION OF SUBJECTS FOR
DISSERTATION
1. / NAME OF THE CANDIDATE AND ADDRESS(IN BLOCK LETTERS) / Dr. CHOUGULE VAIBHAV TAMMANNA
POST GRADUATE STUDENT,
DEPARTMENT OF PEDODONTICS AND
PREVENTIVE DENTISTRY,
BAPUJI DENTAL COLLEGE AND
HOSPITAL,
DAVANGERE-577004.
KARNATAKA
2. /
NAME OF THE INSTITUTION
/BAPUJI DENTAL COLLEGE AND HOSPITAL, DAVANGERE– 577 004.
KARNATAKA.3. / COURSE OF STUDY AND SUBJECT /
MASTER OF DENTAL SURGERY (M.D.S) IN PEDODONTICS & PREVENTIVE DENTISTRY.
4. / DATE OF ADMISSION TO COURSE /25-05-2012
5. /
TITLE OF THE TOPIC
/ “COMPARATIVE EVALUATION OF MICROTENSILE BOND STRENGTH, FLUORIDE RELEASE AND MICROLEAKAGE OF CLINPRO AND FISSURIT F PIT AND FISSURE SEALANTS AT DIFFERENT pH - AN IN VITRO STUDY”6. /
BRIEF RESUME OF THE INTENDED WORK:
6.1: Need for the study:
Anatomic pits and fissures of teeth have long been recognized as susceptible areas for the initiation of dental caries. Treating caries susceptible pits and fissures with resin sealants is a widely accepted preventive strategy. The basic premise for the use of sealants is that they inhibit caries by mechanically preventing bacteria and substrate from penetrating into pits and fissures of tooth occlusal surfaces.1The cariostatic efficacy of fluoride has been a major component of the preventive pedodontic practices. Fluoride has been added to solutions and gels for topical application. Fluoride releasing dental restorative material have been developed with same consideration and have been a subject of interest by research workers.2
The clinical success of sealants in caries prevention depends on the ability of the material to adhere to the enamel surface and isolate pits and fissure from the oral environment. Although the bond strengths of fluoride and non-fluoride containing fissure sealants have been compared, to date no study has examined the tensile bond strength to enamel of sealant using human teeth.1
Most of the studies comparing fluoride release among various dental restorative materials have confirmed the effect of storage media on fluoride release. In the present study the storage media with different PH 4.3, 5.5 and 6.2 have been used in attempt to simulate the oral environment.2
Therefore, this in vitro study aimed to evaluate the microtensile bond strength to human enamel, fluoride release and microleakage of different fissure sealants at different pH simulating oral conditions.
6.2: Review of Literature :
Application of pit and fissure sealant to the newly erupted posterior teeth is the best method to prevent pit and fissure caries and/or to prevent the continued development of incipient caries into frank caries when the incipient lesion is sealed over with resin.3
A study conducted on bovine enamel to evaluate the microtensile bond strength of new fissure sealant and compare it with conventional sealants which were applied to enamel alone and concluded that sealant microtensile bond strength values may be affected by material content. The adhesive may improve micro tensile bond strength values of sealants to enamel.1
In one of the studies it has been concluded that “fluoride release rate was significantly higher in first day which reduced after third day to nearly constant level. At pH 4.3 fluoride release was highest and at pH 6.2 it was lowest”.2
A study conducted for verifying the dose -response relationship in fluoride releasing on mineralization and concluded that pH cycling model proposed was able to verify in vitro dose-response relationship of fluoride releasing material on remineralization.4
R. Vijayaraghavan et al conducted a study to estimate and compare the microleakage of a pit and fissure sealant after etching and laser treatment and concluded that different environmental conditions and different ecologies in various mouth may influence the microleakage of sealant placed using either technique.5
HYPOTHESIS:
Research hypothesis:
· Exposing sealants to pH 4.3,5.5 and 6.2 will affect the microtensile bond strength at 24 hrs
· Exposing sealants to pH 4.3,5.5 and 6.2 will affect the fluoride release at 24 hrs
· Exposing sealants to pH 4.3,5.5 and 6.2 will affect the microleakage at 24 hrs
Null hypothesis:
· Exposing sealants to pH 4.3,5.5 and 6.2 will not affect the microtensile bond strength at 24 hrs
· Exposing sealants to pH 4.3,5.5 and 6.2 will not affect the fluoride release at 24 hrs
· Exposing sealants to pH 4.3,5.5 and 6.2 will not affect the micro leakage at 24 hrs
6.3 Objectives of the study:
1. To evaluate and compare the microtensile bond strength of two sealants at different pH
2. To evaluate and compare the fluoride release of two sealants at different pH
3. To evaluate and compare the microleakage of two sealants at different pH
MATERIALS AND METHODS :
SAMPLE SIZE DETERMINATION :
Based on the available information on fluoride release from previous studies,6 using following formula:
n=2t2s2/d2
where, n=required sample size for each group
s=amount of variation expected in fluoride levels within the sample
d=minimum expected difference in fluoride levels between two sealants
t=theoretical value of t distribution with 95% confidence interval
level of significance =5%
power of study=80%
=2x2.132x2.52 = 9 ~ 10
2.42
n(sample size per group)=10
· Minimum sample derived is 10 per group.
7.1 Source of data:
· 75 extracted teeth for therapeutical reasons will be used in this study.
Materials required:
· Two sealants Clinpro and Fissurit F
· Bonding agent
· 1 % methylene blue dye
· Universal testing machine
· Fluoride electrode
· Stereomicroscope
7.2 Method of Collection of Data:
Study design: Experimental, in-vitro and between group study.
The study groups which will be used in this study are :
Group 1 / pH 4.3 group
Group 2 / pH 5.5 group
Group 3 / pH 6.2 group
Solution preparation :
The demineralizing and remineralizing solution will be prepared in distilled water. pH of the solution will be maintained using pH paper.2
pH paper that will be used for this study will be of same type to standardize the pH level in all solution
Sample preparation :
Each group will be subdivided into two subgroups i.e Clinpro and Fissurit F , each subgroup will be again divided for checking microtensile bond strength, fluoride release and microleakage.
1)To evaluate microtensile bond strength :
Fifteen extracted molar teeth will be cleaned, polished with pumice and will be stored in 0.1% thymol solution at room tempt. The roots will be trimmed and four enamel specimens will be cut. Flat enamel surface will be prepared using carbide paper. Sealants will be applied as per the manufacturer’s instruction. In order to provide support for microtensile bond strength testing hybrid composite resin will be build up. Then specimens will be sectioned into 1 mm thick slabs. Then slabs will be attached by their ends to universal testing machine by cyanoacrylate glue. Fractured slabs will be evaluated under stereomicroscope to identify fracture mode.1
2) To evaluate fluoride release :
Specimens will be prepared of each group as per manufacturer’s instruction and will be placed in plastic moulds 10 mm diameter × 1 mm depth and cured. Fluoride ion estimation will be performed by ion selective electrode method. 6
Fluoride ions released will be measured after 24 hours using ion sensitive electrode (membrane electrode) method.
3) To evaluate microleakage :
Sealant will be applied as per the manufacturer’s instruction. Teeth will be coated with double layer of nail varnish to prevent the leakage of the dye. The occlusal surface will be excluded. All groups will be then immersed inverted in 1 % methylene blue for 24 hrs. Each tooth will be sectioned labio-lingually with diamond wheel measuring 0.02 mm in thickness.
The sections will be cleaned and examined under stereomicroscope for dye penetration.7
STATISTICAL ANALYSIS:
Results will be subjected to appropriate statistical analysis.
· Kruskal Wallis ANOVA will be used for microleakage analysis
· One way ANOVA will be used for simultaneous multiple comparisons followed by POST HOC Duncan’S test for group wise comparison.
· Unpaired‘t’ test will be used to compare between two sealant.
7.3: Does the study require any investigation or interventions to be conducted on patients or other humans or animals? If so, please describe briefly:
Yes, this study requires the collection of teeth extracted for therapeutic reasons.
7.4 : Has ethical clearance been obtained from your institution in case of 7.3
Yes, recommendations of ethical committee are enclosed.
8. /
LIST OF REFERENCES:
1. E Sen Tunc, S Bayrak, N Tuloglu, E Ertas. Evaluation of microtensile bond strength of different fissure sealants to bovine enamel. Aust dent J 2012;57:79-842. Bahadure RN, Pandey RK, Kumar R, Gopal K, Singh RK. An estimation
of fluoride release from various dental restorative material at different pH:
In vitro study. J Indian Soc Pedod Prev Dent 2012;30(2):122-6
3. Simonsen RJ, Neal RC. A review of the clinical application and performance of pit and fissure sealants. Aust Dent J 2011; 56(1 suppl): 45-58
4. Rodrigues E, Delbem ACB, Pedrini D, Cavassan L. Enamel remineralization by fluoride-releasing material : proposal of a pH- cycling model. Braz Dent J 2010;21(5): 446-451
5. Vijayaraghavan R, Rao AR, Reddy NV, Krishnakumar R, Sugumaran DK, Mohan G. Assessment and comparison of microleakage of a fluoride-releasing sealant after acid etching and Er:YAG laser treatment – An in vitro study. Contempt Clin Dent 2012;3(1):64-88
6. Bayrak S, Tunc ES, Aksoy A, Ertas E, Guvenc D, Ozer S. Fluoride release and recharge from different materials used as fissure sealants. Eur J dent J 2010;4:245-50
7. Prabhakar AR, Sankriti A, Murthy, Sugandhan S. Comparative evaluation of the length of resin tags, viscosity and microleakage of pit and fissure sealants- an in vitro scanning electron microscope study. Contempt Clin Dent 2011;2(4): 324-30