Download annexure ii

RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE
KARNATAKA
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. NAME OF THE CANDIDATE AND
ADDRESS
Dr. NILEGAONKAR RUCHA SHRIKANT
POST GRADUATE STUDENT,
DEPARTMENT OF CONSERATIVE
DENTISTRY AND ENDODONTICS,
COLLEGE OF DENTAL SCIENCES,
DAVANGERE-577004
KARNATAKA.
2. NAME OF THE INSTITUTION
COLLEGE OF DENTAL SCIENCES,
DAVANGERE-577004, KARNATAKA.
3. COURSE OF STUDY AND SUBJECT MASTER OF DENTAL SURGERY (M.D.S.)
IN CONSERVATIVE DENTISTRY AND
ENDODONTICS
4. DATE OF ADMISSION TO COURSE
31-05-2013
5. TITLE OF THE TOPIC
EFFECT OF COMMERCIAL MOUTH
RINSES ON MICROHARDNESS OF
FOURESTHETIC RESTORATIVE
MATERIALS- AN IN VITRO STUDY.
1
6. Brief Resume of the intended work :
6.1 Need for the study
Tooth coloured restorative materials are widely used to replace missingtooth structure and
modify tooth color and contour, thus enhancing esthetics. More recently nanocomposites
have become available, which are optimized for both excellent esthetics and high mechanical
properties for stress bearing areas.The demand for products having both adhesive and cariesprotective properties has led to the development of resin-modified glass–ionomer(hybrid)
and polyacid-modified resin composite (compomer) aesthetic restorative materials.1These
materials combine the advantages of conventional GI cements of adhesion to tooth structure
and fluoride release and the advantages of light-cured resins which are good esthetics and
ease of manipulation.
Mouth rinses are widely used to control dental caries and periodontal diseases, with some
individuals using mouth rinses at a frequency of six times per day. 2Mouth rinses contain
water, antimicrobial agents, salts, preservatives and in some cases alcohol. The variation in
the concentration of these substances affects the pH of the mouth rinses.3Alcohol in the
mouth rinses may soften the resin composite4and glass ionomers8,9and this effect is found to
be directly related to the percentage of alcohol.5 Low pH affects sorption, solubility and
surface degradation of these restorative materials.6,9Studies about the effects of mouth rinses
on restorative materials are limited.
Thus, the purpose of this study is to examine the effects of fourmouthrinses on four different
aesthetic restorative materials by analyzing the surface microhardness.
2
6.2 Review of literature
A study was carried out to evaluate the effect of alcohol-containing and alcohol-free
mouthrinses on the microhardness of visible light cured (VLC) composite resin (Amelogen),
VLC glass–ionomer cement (Fuji II LC) and a fissure sealant (Ultra Seal XT). Samples of
the restoratives were stored for 12 hours to simulate a 2 min/day for 1 year exposure to
mouthrinses in the following solutions: distilled water (control), alcohol-containing
mouthrinse (Viadent) and alcohol-free mouthrinse (Rembrandt). Both mouthrinses affected
the hardness of the materials tested. The microhardness of all three materials was found to be
reducedmore in alcohol containing mouthrinsedue softening of resin matrix because of
presence of ethanol in the mouth rinse.7
An in vitrostudy was carried out to examine the effects of three proprietary mouthrinses
oncomposite, glass ionomer cement and compomer. Changes between baseline and after
treatment measurements of surface microhardness and colour of the test materials were
established by using Vickers microhardness tester and spectrophotometer. Among the
materials tested, composite resin material showed a slight softening in the mouthrinse with
lowest pH. Low pH caused surface degradation of the material. Hardness of glass–ionomer
material decreased in the mouthrinse with highest ethanol content and that ofcompomer
decreased in the mouth rinse with highest pH. It was concluded that this effect was due to the
water content of the mouth rinses8
A study was conducted to investigate the effect of commercially available mouthrinses on
the microhardness and wear of composite (Esthet-X, Dentsply) and compomer (Dyract
Posterior, Dentsply) restoratives. The following solutions were used: distilled water;
3
Listerine Original [AP] (alcohol-containing essential oil/phenolic compound mouthrinse);
Colgate Chloropharm [AC] (alcohol-containing chlorhexidinemouthrinse); Oral B Tooth &
Gum Care [AF] (alcohol-containing fluoride mouthrinse); Oral B Tooth & Gum Care
Alcohol Free [OF] (alcohol free fluoride mouthrinse) and Oral B Sensitive [PF] (fluoride
mouthrinse). After conditioning, the specimens were subjected to hardness testing. Dyract
was significantly softened by AP, while Esthet-X was significantly softened by AC and AP.9
An in vitro study evaluated the effects of three mouthrinses (Listerine--alcohol containing,
Oral B--alcohol free and Rembrandt Plus--peroxide whitening rinse) on the surface hardness,
gloss and colour of a nanofill (Filtek Supreme) and nanohybrid (Simile) composite resin that
had been subjected to bleaching treatment. The hardness, gloss and CIELABcolour
parameters of each specimen were assessed prior to the experiments. Specimens were
exposed to the 10% carbamide peroxide bleaching agent (Vivastyle) for 2 hours per day for
14 days. Following the bleaching treatment measurements were repeated. The specimens
were then conditioned with mouthrinses for 12 hours. The specimens were measured again
for hardness, gloss and colour. Bleaching treatment and the use of mouthrinses affected the
hardness, gloss and colour of both resins. Significant differences were observed with the use
of mouthrinses for all parameters. Rembrandt Plus promoted the greatest changes, followed
by Listerine and Oral B.10
An in vitro study was carried out to evaluate the effect of different mouthwashes on
superficial roughness and Knoop hardness of two resin composites (4 seasons and Esthet-X),
Storage solutions used were - Distilled water; Colgate Plax Overnight; Colgate Plax Alcohol
Free; and Colgate Plax Whitening. For Knoopmicrohardness analysis, there was a significant
reduction for all groups after 12 hours and 24 hours. It was concluded that the mouthwashes
4
containing hydrogen peroxide and/or alcohol decrease the microhardness of the resins
tested.11
An in vitro study was designed to comparatively evaluate the effect of five commercial
mouth rinses on the micro hardness of a nanofilled resin based restorative material(Filtek
Z350XT, 3M ESPE, St.Paul, MN USA). Mouth rinses used were –Listerine (alcohol based),
Periogard (alcohol based), Colgate plax (alcohol based), C- prev (alcohol free),
Hiora(alcohol free). The post immersion micro hardness values of the specimens were
recorded.Significant reduction in the mean VHN (Vicker's micro hardness number) was
observed in all the groups after exposure to the tested mouth rinses. All the mouth rinses
showed a reduction in the microhardness of nanofilled resin composite material with listerine
containing maximum amount of alcohol, showing highest reduction in micro hardness
value.12
5
6.3 Aims and objectives of the study
This in vitro study is designed to comparatively evaluate the effect of four commercial
mouth rinses on the micro hardness of composite resin, resin modified glass ionomer
cement, conventional glass ionomer cement and compomer.
7. Materials and methods
7.1 Source of data
Materials required:
1. Filtex Z350 composite resin
2. VLC GIC-FUJI II
3.Dyract Posterior, Dentsply
4. GC Fuji II GIC
5. Mouth rinses –
i.
Listerine
ii.
Colgate Plax
iii.
Oral B Sensitive
iv.
Hiora (Himalaya)
Methodology:

SPECIMEN PREPARATION: 40 specimens of resin composite (FiltekZ350)
material with 3mm diameter and 3mm height will be prepared using a plastic mold.
6
The mold will be placed on a glass slide and filled with resin composite to a slight
excess using composite filling instrument, covered with a clear matrix strip and
another glass slide was placed on top and gently pressed for 30s to extrude excess
material to obtain a smooth surface. Each specimen will be cured for 40s from the top
and another 40s from the bottom using LED light cure unit(3M ESPE Elipar S10).
40 specimens each of RMGI (Fuji II LC) and compomer (Dyract Posterior) will be
prepared by manipulating them according to manufacturer’s instructions. After
manipulation, the specimens will be prepared in a manner similar to the composite
specimens by filling them into plastic molds and light curing them.
40 specimens of conventional GIC (GC Fuji II) will also be prepared. After
manipulating the material according to manufacturer’s instructions, it will be placed
into plastic moulds of 3mm diameter and 3mm height. The mould will be placed on a
glass slide and covered with a matrix strip and a glass slide over it. The glass slides
will be gently pressed and held in this position till the material sets by chemical
reaction.

pH EVALUATION: The pH of the mouth rinseswill be recorded using a digital pH
meter (Labman Scientific Instruments Microprocessor pH mV Temperature meter).

The specimens will randomly be allocated into 4 major groups by simple random
sampling according to the mouth rinses. Each group will further be divided into 4
subgroups based on the restorative material. Each subgroup will contain 10
specimens of the respective restorative material.
7
I.
Group I: Listerine (alcohol-based; 21.6% alcohol)
a. FiltexZ350 (n=10)
b. Fuji II LC (n=10)
c. DyractPosterior (n=10)
d. GC Fuji II (n=10)
II.
Group II: Colgate Plax (alcohol-based; 7.2% alcohol)
a. FiltexZ350 (n=10)
b. Fuji II LC (n=10)
c. DyractPosterior (n=10)
d. GC Fuji II (n=10)
III.
Group III: Oral B sensitive (alcohol free)
a. FiltexZ350 (n=10)
b. Fuji II LC (n=10)
c. DyractPosterior (n=10)
d. GC Fuji II (n=10)
IV.
Group IV: Hiora (alcohol free)
a. FiltexZ350 (n=10)
b. Fuji II LC (n=10)
c. DyractPosterior (n=10)
d. GC Fuji II (n=10)
8
7.2 Method of collection of data
The baseline micro hardness values of the specimens will be recorded prior to immersion in
the mouth rinses.Microhardness will be measured using Vicker’s micro hardness tester
(Reichert Austria Make. Sr. No. 363798). A load of 40g will applied on the test specimens
with a dwell time of 15s.
The specimens will then be immersed in 20ml of respective mouth rinsesand kept in an
incubator at 37o C for 24h.
Then specimens will then be removed from the mouth rinses and dried. Microhardness
values will then be checked for each specimen using the same micro hardness tester and
same load and dwell time as previously mentioned for pre-immersion test.
7.3 Statistical Analysis:
The intra-group comparison for each restorative material will be done by Paired T test. One
way ANOVA test on SPSS package will be carried out for inter-group comparison followed
by Tukey’s Post-hoc Analysis.
7.4 Does the study require any investigations or interventions to be conducted on
patients or other humans or animals? If so, please describe briefly.
Not applicable
7.5 Has ethical clearance been obtained from your institution in caseof 7.3
Not required
9
8. List of references:
1. Ronald L. Sakaguchi, Powers JM.Craig’s restorative dental materials.
13thedn. Elsevier 2012. p. 162-63
2. Moran JM. Chemical Plaque Control prevention for the masses.
Periodontology 2000; 15: 109-17
3. Bhatti SA, Walsh TF, Douglas CW. Ethanol and pH levels of proprietary
mouth rinses. Community Dent Health 1994; 11: 71-4
4. Asmussen E. Softening of BIS GMA based polymers by ethanol and by
organic acids of plaque. Scand J Dent Res 1984; 92: 257-61
5. Penugonda B, Settembrini L, Scherer W, Hittel E, Strassler H. Alcohol
containing mouth washes: effects on composite hardness. J Clin Dent 1994; 5:
60-2
6. Almeida GS, Poskus LT, Guimaraes JG, Da Silva EM. Effect of mouth
rinses on salivary sorption, solubility and surface degradation of a nanofilled
and a hybrid resin composite. Oper Dent 2010; 35: 105-11
7. Gürgan S, Onen A, Köprülü H.In vitro effects of alcohol-containing and
alcohol-free mouthrinses on microhardness of some restorative materials.J
Oral Rehabil 1997 Mar;24(3):244-6.
8. P. Gürdal, B. GünizAkdeniz, B. Hakan Sen.Journal Oral Rehabil 2002;
29(4).P. 895–901
9. Yap AU, Tan BW, Tay LC, Chang KM, Loy TK, Mok BY.Effect of
10
mouthrinses
on microhardness and
wear
of composite and
compomer
restoratives. Oper Dent. 2003 Nov-Dec;28(6):740-6.
10. Gurgan S, YalcinCakir F.The effect of three different mouthrinses on the
surface hardness, gloss and colour change of bleached nano composite
resins.Eur J ProsthodontRestor Dent. 2008 Sep;16(3):104-8.
11. Diogo de Azevedo M, Eduardo dos Santos Bertoldo C; Flávio Henrique
BaggioAguiar; DéboraAlvesNunesLeite Lima; Lovadino JR. Effects of
mouthwashes on Knoop hardness and surface roughness of dental composites
after
different
immersion
times.Braz.
Oral
Res.
2011;25(2) São
Paulo Mar./Apr. 2011
12. Jyothi KN, Crasta S, Venugopal P. Effect of five commercial mouth rinses
on the microhardness of a nanofilled resin composite restorative material:
An in vitro study. Journal of conservative dentistry Jul-Sep 2012;15(3): 21417
11
12