RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES,
BANGALORE, KARNATAKA,
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. / Name of the CandidateAnd Address (in block letters) /
Dr. NISHANTH. P
POSTGRADUATE STUDENT
DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICS,BAPUJI DENTAL COLLEGE AND HOSPITAL,
DAVANGERE – 577 004,
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 CONSERVATIVE DENTISTRY AND ENDODONTICS
4. / Date of admission to THE COURSE / 15/05/2012
5. /
Title of the dissertation:
/ “COMPARATIVE EVALUATION OF SHEAR BOND STRENGTH OF THREE DENTAL ADHESIVES UNDER DRY AND WET BONDING CONDITIONS – AN IN VITRO STUDY’’6.
/ BRIEF RESUME OF INTENDED WORK
6.1 Need for the study:
Adhesive procedures have become an integral part of modern restorative dentistry. The durability of the adhesive bond between resin and tooth is of significant importance for the longevity of adhesive restorations.1 There has been a dramatic progression in the adhesion of dental adhesives and resins to enamel and dentin in last 40 years since Buonocore introduced the technique of etching with phosphoric acid to improve adhesion to enamel.2 Over the years as the demand for esthetic restorations have increased, technique simplification has become the goal of researchers and manufacturers of different adhesive system leading to different generations in dental adhesive.3 Total etch comprises of fourth and fifth generations; it uses phosphoric acid etching step, to modify both enamel and dentin surfaces which allows the penetration of adhesives into tooth surface and achieves a micromechanical bond. Self etch comprises of sixth and seventh generations. These compounds bear carboxylic or phosphoric acid groups and achieves the creation of a micromechanical retention pattern by etching the tooth structure and chemical bonding by complex formation with the calcium ions present in the tooth.4
A new bonding agent SINGLE BOND UNIVERSAL (3M ESPE) has been recently introduced into the market. The manufacturers claim it is a single-bottle system for all surfaces, and can be used in total-etch, self-etch or selective-etch mode for both direct and indirect restorations. Hence the objective of this study is to evaluate the shear bond strength between Single bond universalTM with a self-etch bonding system and total etch bonding systems.
RESEARCH HYPOTHESIS (H1):- There is a difference in the shear bond strength of the three dental adhesives under dry and wet bonding conditions.
NULL HYPOTHESIS (Ho):- There is no difference in shear bond strength of the three dental adhesives under dry and wet bonding conditions.
6.2 Review of literature
An in vitro study was done to evaluate shear bond strength of total etch three step and two self etching one step dentin bonding system. On one hundred twenty six recently extracted non carious human molars three dentin bonding agents were used: - scotch bond multipurpose plus (3M ESPE), a three step conventional adhesive system; prompt L pop (3M ESPE), two one step self etching primer adhesive system. After the preparation of specimen shear bond strength was recorded. Data was statistically analyzed. Prompt L pop 2 showed high bond strength compared to other.4
An in vitro test was done to evaluate shear bond strength of one 4th generation and two 7th generation bonding agents. A total of 108 molars were divided into 12 groups of nine teeth each; 1) scotch bond mp; 2) adper prompt L pop (7th gen) and 3) I bond gluma inside (7th gen), after preparation of the specimen shear bond was determined under universal testing machine. Scotch bond MP performed better. Scotch bond MP and I bond bonded better to dentin.5
An in vitro test was conducted to evaluate shear bond strength of self etch and total etch system at different dentin depths using 4 adhesive systems – 1) adper single bond 2, 2) adper prompt L – pop, 3) Magic bond DE, 4) Self etch bond in regard to buccal and lingual surfaces as well as dentin depth. For all groups wet bonding technique was applied. Specimens were testing under EMIC universal testing machine. Adper single Bond 2 demonstrated highest shear bond strength.6
An in vitro study was done to determine shear bond strength of two different bonding agents with two different desensitizers. Eighty molars were taken which were ground to expose dentin. The teeth were divided into four major groups. Each major group was subdivided into four subgroups of 10 samples each. Group 1A and IIA were treated as dry bonding groups, Groups 1B and IIB were treated as wet bonding groups, Groups 1Cand IIC were rewetted with Gluma desensitizer, and groups ID and IID were rewetted with Vivasens desensitizer. Major group I was treated with Gluma comfort bond and charisma. Major group II was treated with Prime and Bond NT and TPH. The samples were thermo cycled and shear bond strength was evaluated using Instron machine. The specimens rewetted with Gluma desensitizer showed the highest shear bond strength.7
An in vitro study was done to determine shear bond strength and the effects of increasing thermo cycling regimens. Adper single bond (3M ESPE) was used for bonding resin composite to human enamel and dentin. Specimens were stored in water (370C, 24 h) and subjected to thermo cycling (50C AND 550C) in five groups: 1) control (no thermo cycling), 2) 100, 3) 500, 4) 2000, 5) 10,000 thermocycles respectively. Micro shear bond strength was performed at a crosshead speed of 1mm/min. Artificial aging decreased dentin bond strength in groups 4 and 5 compared to control.8
6.3 Objective of the Study
To compare and evaluate the shear bond strength of Total etch (Adper single bond II), Self etch (Adper easy bond), and single bond universal adhesives (self and total etch) under dry and wet bonding conditions by using universal testing machine.
7. MATERIALS AND METHODS:
7.1 TYPE OF STUDY – In vitro study
SOURCE: The study will be performed on ‘60’ number of extracted mandibular molars.
MATERIALS USED:
10% Buffered formalin
Micromotor handpiece(NSK)
Diamond disc (double sided)
600 grit silicon carbide paper
Scotch bond multipurpose etchant 37% (3M ESPE)
Single bond universal(3M ESPE)
Adper easy bond(3M ESPE)
Adper single bond II (3M ESPE)
Filtek Z350XT Nanohybrid restorative material (3M ESPE)
Distilled water
Light emitting diode (LED ) curing light (EliperTM Free Light 2 LED curing light,3M ESPE)
Universal testing machine
7.2 Method of collection of data (including sampling procedure, inclusion, and Exclusion criteria if any)
Inclusion criteria:
1. Sound extracted human permanent mandibular molars stored in 10% formalin (extracted for periodontal reasons).
Exclusion criteria:
1. Dental caries.
2. Any previous restorative or endodontic treatment.
3. Fractured teeth.
4. Attrition, abrasion, erosion.
5. Flourosed teeth , Hypoplastic teeth
METHODOLOGY
· For the proposed study 60 extracted non carious permanent human mandibular molars fulfilling the absolute inclusion and exclusion criteria will be used as sample for study. The teeth will be randomized using a chit system into four groups of 15 teeth each. Teeth will be cleaned with an ultrasonic scaler. Each tooth will be decoronated using a diamond disc with water coolant until dentin will be exposed. The cut dentin surface will then be abraded against 600-grit wet silicon carbide papers for 60 seconds to produce a uniform smear layer. The remaining apical part of each tooth up to 1mm from cemento enamel junction will be mounted on a plastic ring using acrylic resin and teeth will be divided into four groups with 15 teeth in each group. Following application of adhesive, a Teflon mold will be used to build composite resin cylinder on the dentinal surface of all samples, measuring 2mm in diameter & 3mm in height in a two layer increment technique.3,5,6
· Each layer is light cured according to manufacturer‘s instruction. After polymerization the specimen will be placed in distilled water for 24 hrs. Then the samples are thermocycled between 50C and 550C for 500 thermocycles.8
· Group A-Total etch system Single bond II (3M ESPE) (wet bonding)
After decoronation of crown and exposure of dentin. Etchant will be applied on cut tooth surface. After waiting for 15 seconds, it will be rinsed for 10 seconds. After blotting excess water, 2-3 consecutive coats of adhesive will be applied with gentle agitation. It will be air thinned for 5 seconds. Followed by light curing for 10 seconds.
· Group B- Self etch adhesive two step system Adper EASYBOND (3M ESPE) (wet bonding)
After de coronation of crown and exposure of dentin .The adhesive will be applied to tooth surface for 20 sec. The adhesive will be dried for 5 sec. Followed by light curing for 10 sec.
· Group C- Self etch adhesive system Single bond universal (3M ESPE)(wet bonding)
The adhesive will be applied to tooth surface for 20 sec. The adhesive will be dried for 5 sec. Followed by light curing for 10 sec.
· Group D-Total etch system Single bond universal (3M ESPE)(dry bonding)
Etchant will be applied on cut tooth surface. After waiting for 15 seconds it will be rinsed for 10 seconds. After drying excess water, 2-3 consecutive coats of adhesive will be applied with gentle agitation. It will be air thinned for 5 seconds. Followed by light curing for 10 seconds.
The adhesives will be applied to the cut tooth surface. For all groups, the composite will be placed in 2-3 layers. Each increment will be cured using a LED curing unit according to manufacturer’s instruction.
After 24-h storage in distilled water at 37ºC, the samples are thermocycled between 50C and 550C for 500 thermocycles. The shear bond strength will be determined using a knife-edge blade in a universal testing machine at a crosshead speed of 1 mm/min.
EVALUATION OF SHEAR BOND STRENGTH:-
SHEAR BOND STRENGTH = LOAD
(MPa) SURFACE AREA(mm)2
CALCULATION OF SAMPLE SIZE :
Based on available information, the sample size required for study was estimated using the formula
n = 2 x t2 x s2
d2
n = 2 x 2.132 x (6.0)2
(5.0)2
= 13(Minimum sample in each group)
Therefore sample size for each group is 15.
Where t = theoretical value of t distribution for 95% confidence = 2.13
s = pooled standard deviation = 6 (from previous study)
d = minimum expected difference in shear bond strength
Between 2 groups for significance
= 5 mpa (from previous study)
Level of significance = 5% (α)
Power of study = 1- β =1- 0.20 =0.80 = 80%
STASTICAL ANALYSIS
Results will be subjected for appropriate statistical analysis.
One way ANOVA will be used for multiple comparisons.
POST- HOC-TUCKEY ΄S test will be used for pair wise comparison.
7.3 Does the study require any investigation or intervention to be conducted on the patients or other human or animals? If so, please describe briefly.
NO. Extracted human teeth will be used for the study.
7.4 Has the ethical clearance been obtained from your institution in case of 7.3
Will be obtained from institution.
REFERENCES
1. Scholtanus D, Kenny P, Nilgun D, Cees JK, Albert JF. Micro tensile bond strength of three simplified adhesive systems to caries affected dentin. J Adhes Dent 2010; 12(4):273-78.
2. Abdalla AI, Eraki MEL, Feilzer AJ. Effect of direct and indirect water storage on the micro tensile bond strength of a total etch and two self-etch adhesives. Am J of Dent 2007; 20(6): 370-3.
3. Yaseen SM , Subba Reddy VV. Comparative evaluation of shear bond strength of two self-etching adhesives (sixth and seventh generation) on dentin of primary and permanent teeth: An in vitro study J Indian Soc Pedod Prev Dent; Jan-Mar 2009; 27(1); 33-38.
4. Maurin J C, Lagneau C, Durand M, Lissac M. Tensile and Shear bond strength of a total etch three –step and two self-etching one- step dentin bonding systems. J Adhes Dent 2006; 8; 27-30.
5. Soderholm K J, Guelmann M, Bimstein E. Shear bond strength of one 4th generation and two 7th generation bonding agents when used by operators with different bonding experience. J Adhes Dent 2005; 7: 57-64.
6. Maita Villela-Rosa A C, Goncalves M, Augusta Orsi I, Miani PK. Shear bond strength of self-etch and total etch bonding system at different dentin depths. Braz Oral Res Mar-Apr 2011; 25(2): 109-15.
7. Ravi Kumar N, Shankar P,Indira R. Shear bond strength of two dentin bonding agents with two desensitizers: An invitro study. J Conserv Dent Jul-Sep 2011; 14(3): 247-253.
8. Hariri I, Shimada Y, Sadr A, Ichinose S, Tagami J. The effects of aging on shear bond strength and Nano leakage expression of an etch-and-rinse adhesive on human enamel and dentin. J Adhes Dent 2012; jun14(3); 235-43.
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