RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, BANGALORE,

KARNATAKA

MDS – PROSTHODONTICS INCLUDING CROWN, BRIDGE AND IMPLANTOLOGY

SYNOPSIS FOR REGISTRATION OF DISSERTATION


RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES

BANGALORE, KARNATAKA.

ANNEXURE II

PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION

1. / NAME OF CANDIDATE
AND ADDRESS / Dr. SUMEET SINGH
POST GRADUATE STUDENT
DEPARTMENT OF PROSTHODONTICS
M R AMBEDKAR DENTAL COLLEGE AND HOSPITAL
1/36 CLINE ROAD, COOKE TOWN
BANGALORE-560005
2. / NAME OF THE INSTITUTION / M R AMBEDKAR DENTAL COLLEGE AND HOSPITAL
1/36, CLINE ROAD ,COOKE TOWN
BANGALORE-560005.
3. / COURSE OF STUDY &
SUBJECT / MASTER OF DENTAL SURGERY
IN
PROSTHODONTICS
INCLUDING CROWN, BRIDGE AND IMPLANTOLOGY
4. / DATE OF ADMISSION TO COURSE / 31/07/2013
5. / TITLE OF TOPIC / “ A COMPARATIVE STUDY TO EVALUATE THE EFFECT OF COMMERCIALLY AVAILABLE DENTURE CLEANSERS ON SURFACE HARDNESS AND ROUGHNESS OF DENTURE LINERS AT VARIOUS TIME INTERVAL”- AN IN-VITRO STUDY
6.
7.
8. / BRIEF RESUME OF INTENDED WORK :
6.1 NEED FOR THE STUDY :
Proper hygienic care of relined prosthesis is an important means of maintaining a healthy oral mucosa. Chemical agents used for their maintenance do not preserve the standard of the prosthesis, it is consider as a failure.
Soft liners are the material, which act as an intermediary between the soft tissue and hard prosthesis. Soft liners include silicone elastomers and plasticized acrylic resins and have a key role in modern removable prosthodontics because of their capability of restoring health to inflamed and distorted mucosa. They act as a cushion for the denture-bearing mucosa through absorption and redistribution of forces.
Patients using removable prosthetic restorations lined with an elastic material should carry out regular cleansing procedures to prevent infection. Mechanical cleansers are not advisable since it can damage the resilient liners. Chemical cleansers are the first choice for plaque control. Certain chemical substances leached out of the soft liners by disinfecting solutions, which deteriorates their mechanical properties and they become harder and their elasticity decreases. The loss of the elastic properties of denture liners may intensify the traumatic influence of the prosthesis on the tissues and reduce the comfort for the wearer.
As per the data acquired through studies conducted, hygiene procedures have been found to have an effect on the physical and mechanical properties of resilient denture liners. Thus, the aim of this study is to evaluate the effect of commercially available denture cleansers on surface hardness and roughness of denture liners.
6.2. REVIEW OF LITERATURE:
An In-vitro study was done to evaluate the effects of a denture cleanser on weight change, roughness, and tensile bond strength of two resilient denture liners.Specimens of microwave acrylic resin were prepared, relined with a resilient liner and treated with denture cleanser. Roughness was evaluated by using profilometer and tensile bond strength was determined using universal testing machine. It wasconcluded that specimens immersed in denture cleansers demonstrated increase weight changes of resilient liners when compared with tap water1.
An in vitro study was conducted to investigate the effect of denture cleansers on soft denture liners. The specimens were prepared made of acrylic and silicon liners, immersed in distilled water and food colorants for a week alternatively in the denture cleanser. The measurements were made using colorimeter at the start of the study followed by measurement after immersion in food colorants and denture cleansers for three month. It was concluded that the silicone based soft denture liners are more resistant to staining2.
An in vitro study was conducted to evaluate the effect of storage duration on the hardness and tensile bond strength of silicone and acrylic resin based resilient denture liners. They used definitive acrylic resin based heat polymerized, interim acrylic resin based auto-polymerized, definitive silicone based heat polymerized and definitive silicone based auto-polymerized resilient liners. Specimens were stored in water at 370 c for 1, 3 Or 6 months. Based on results of this study it was concluded that definitive silicone based heat polymerized resilient liner had lower bond strength and higher hardness value3.
An in-vitro study was performed to evaluate the efficacy of denture cleansers on Candida biofilms formed on polyamide andPoly methyl methacrylate resin. Resin specimens were prepared and surface roughness was standardized. Candida albicansbiofilm was formed for 72 hours and specimens were treated with an enzymatic cleanser solution. Remaining adherent microorganisms were removed from the treated specimens by ultrasonic waves, colony-forming units of each microorganism were calculated and data was analyzed. It was concluded that the highest Candidabiofilm growth occurred on polyamide resin compared to Poly Methyl Methacrylate and denture cleansers were able to remove Candidabiofilm formed on both denture base resins4.
An in-vitro study was conducted to investigate the effect of thermocycling on the hardness, absorption, solubility, and colour change of soft denture liners. Liner materials based on acrylic resin and silicone were tested before and after 2000 thermal cycles. A total of 20 specimens of each material were tested. Half of the specimens were used for hardness and colour evaluation and the remainder for absorption and solubility tests. The hardness was evaluated using a Shore-A-Durometer while absorption and solubility tests were performed by storing samples in a desiccator and weighing daily until reaching constant mass. After thermocycling, the samples were again weighed and dried. Colour was measured
using a spectrophotometer. It was concluded that thermocycling significantly affected the hardness of the specimen and silicone liners performed significantly better compared to acrylic resin5.
6.3OBJECTIVES OF THE STUDY
  1. To determine the influence of denture cleansers on surface hardness and surface roughness of denture liners.
  2. To compare the efficiency of commercially available denture cleansers on denture liners.
MATERIALS AND METHODS :
  1. A total of 120 standardized denture liner specimen will be made using two different denture liners.
  2. Two commercially available denture cleansers and artificial saliva will be used.
Denture liners:
  1. GC Reline soft - Silicone liner
  2. KOOLINER - Acrylic liner
Denture Cleansers:
  1. Efferdent Plus
  2. Polident
Equipment’s:
  1. Shore A Durometer → For Surface hardness
  2. Profilometer → For Surface roughness
METHOD:
Total of one hundred and twenty(120) specimens will be made of the dimension of 15mm x 10mm with the help of custom made mold. Soft liners will be manipulated according to manufacturer’s instruction and expressed into the mold. Once the material sets, the specimens will be removed from the mold and excess will be trimmed.
The specimens will be divided into three major groups based on cleansers used. Group A (Control), B (Efferdent) and C (Polident). Each groups will be further divided into four sub groups to be tested at different time interval of 1 day, 7 days, 30 days and 90 days. Each subgroup will again be divided into two minor subgroups based on denture liner used (that is- acrylic based soft denture liner and silicone based soft denture liners). All the specimens will be stored in artificial saliva throughout the study.
Group (A) will be cleaned daily by water, Group (B) will be immersed in Efferdent denture cleanser solution for ten minutes daily, rinsed with water and store in artificial saliva. Group (C) specimens will be immersed in Polident denture cleanser solution for ten minutes, cleaned with water and stored in artificial saliva. The specimens of all four groups will be tested at 1 day, 7 days, 30 days and 90 days time interval.
The hardness of the specimens will be tested using Shore-A-Durometer and surface roughness will be tested using Profilometer. Reading will be then subjected to statistical analysis (ANOVA).
7.1 SOURCE OF DATA:
The values obtained from the above tests will be source of data. Shore-A-Durometer evaluates surface hardness and Profilometer evaluating surface roughness for different samples.
7.2 METHOD OF COLLECTING DATA:
By using Shore-A-Durometer and Profilometer, surface hardness and surface roughness values for different samples will be collected. Data collected will be analyzed statically using ANOVA and statistical software on personal computer.
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.
No
7.4 Has ethical clearance been obtained from your institution in case of 7.3?
Not applicable
LIST OF REFERENCES:
  1. Garcia RM, Léon BT, Oliveira VB, Del BelCury AA.Effect of a denture cleanser on weight, surface roughness and tensile bond strength of two resilient denture liners.(J ProsthetDent 2003; 89:489-94).
  1. DuyguSarac, SinasiSarac, Murat Kurt, Emir Yuzbasioglu. The effectiveness of denture cleansers on soft denture liners colored by food colorant solutions. (J Prosthodont 2007; 16:185-191).
  1. AyseMese, Kahraman,G. Guzel.Effect of storage duration on the hardness and tensile bond strength of silicon and acrylic resin based resilient denture liners to a processed denture base acrylic resin. (J Prosthet Dent 2008; 99:153-159).
  1. de FreitasFernandes FS, Pereira-Cenci T, da Silva WJ, Filho AP, Straioto FG, Del BelCury AA.Efficacy of denture cleansers on Candida spp. biofilm formed on polyamide and Polymethyl methacrylate resins. (J Prosthet Dent 2011; 105:51-58).
  1. Mancuso DN, Goiato MC, Zuccolotti BC, Moreno A, dos Santos DM, Pesqueira AA.Effect of thermocycling on hardness, absorption, solubility and colour change of soft liners. (Gerodontology 2012; 29:e215-e219).

9. / SIGNATURE OF THE
CANDIDATE
10. / REMARKS OF GUIDE
11. / NAME AND DESIGNATION OF GUIDE /

Dr. MOHAMMED H.S.

READER
DEPARTMENT OF PROSTHODONTICS
12. / SIGNATURE
13. / NAME AND DESIGNATION OF THE CO- GUIDE
14. / SIGNATURE
15. / HEAD OF THE DEPARTMENT / Dr. AMARNATH G S
PROFESSOR & HEAD,
DEPARTMENT OF PROSTHODONTICS.
16. / SIGNATURE
17. / REMARKS OF THE PRINCIPAL
18. / SIGNATURE

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