DISSERTATION- SYNOPSIS
DR. JYOTHSNA SUJAY JATHANNA
DEPT. OF CONSERVATIVE DENTISTRY & ENDODONTICS
KVG DENTAL COLLEGE AND HOSPITAL,
SULLIA.
BATCH OF 2012-15.
RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
BANGALORE- KARNATAKA
ANNEXURE- II
RAGIV GANDHI UNIVERSITY OF HEALTH SCIENCES
BANGALORE-KARNATAKA
ANNEXURE-II
PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
1.NAME OF THE CANDIDATE AND ADDRESS / DR.JYOTHSNA S JATHANNAPOST GRADUATE STUDENT
DEPT OF CONSERVATIVE DENTISTRY ENDODONTICS
K.V.G DENTAL COLLEGE HOSPITAL, KURUNJIBAGH,
SULLIA-574327.
2.NAME OF THE INSTITUTION / K.V.G.DENTAL COLLEGE& HOSPITAL
3.COURSE OF STUDY &SUBJECT / MASTER OF DENTAL SURGERY IN CONSERVATIVE DENTISTRY ENDODONTICS.
4.DATE OF ADMISSION TO COURSE / 30-05-2012.
5.TITLE OF THE TOPIC / COMPARATIVE EVALUATION OF SURFACE ROUGHNESS AND TEXTURE OF POLISHED NANOFILL AND NANOHYBRID COMPOSITES USING PROFILOMETER AND SCANNING ELECTRON MICROSCOPE----AN IN-VITRO STUDY.
6. BRIEF RESUME OF THE INTENDED WORK
6.1 Need for study
Composites have been widely used in past decades to restore both anterior and posterior teeth. A unique drawback inherent to most composites is the difficulty in polishing that often results in dull or rough surface. Composites differ mainly in their inorganic component. Type of inorganic filler, the size of the particles, and extent of filler loading vary widely among composites. Such factors influence the polishability of composites.1. Adequate finishing and polishing of resin composites is a prerequisite for high quality esthetics and enhanced longevity of resin based restorations. A smooth, highly polished restorations are esthetically more appealing and easier to maintain than restorations with more roughened surface. So less susceptible to plaque accumulation , extrinsic discolouration and provides improved mechanical properties.2
Various techniques have been studied to produce a smooth composite surface. Characterisation of surface texture of composites has become increasingly important. It is recognized as a key factor affecting function in clinical service. Measurement and analysis of surface of composites provide an excellent diagnostic tool for comparing both proprietary composites and process that produces polished surface. There is a desire to understand three dimensional surface structure of an observed material because of 3D nature of surface and its interactions in-vivo. Currently refined measurement and analysis techniques have provided tools and approaches required to carry out sophisticated analysis of surface topography.3
A highly polished composite restoration is necessary to help promote plaque free environment.4Good polishability is imperative to obtain smooth finish, increased surface energy and thus to resist accumulation of plaque, debris, or food stains.5
Since the introduction of composite resins, numerous studies have been initiated to develop a finishing and polishing procedure that would produce a smooth surfaced restoration. By the time a study was completed , composites and polishing agents had been replaced by newer materials. These events identified the need for continuous research.6
Purpose of this study is to investigate surface roughness and texture of three different composites Filtek Z250-XT, Tetric-N-ceram bulkfill and ceram X duo which are polished by three clinically different finishing techniques. It is evaluated by using 3D profilometry and scanning electron microscope.
6.2 Review of Literature
Evaluation of surface roughness of four anterior and four posterior composites were compared using a Mylar strip, an unfilled resin as a glaze, polishing with three rubber point polishers and three different manufacturer’s series of disks ( Sof-Lex, Supersnap, moore’s disks). Anterior and posterior composites evaluated were Bis-Fil M and Bis-Fil I, Prisma-Fil and Ful-Fil, Silux and P-30 and Heliosit and Heliomolar. A total of 320 specimens were prepared into disks of 2mm thickness and 10mm diameter. All specimens were polished with star Titan low speed hand piece for 30 seconds using different polishing systems. They were rinsed with water and allowed to dry for 24 hours. Surface roughness (Ra) value was evaluated under scanning electron microscope. Slight differences were discovered between the pairs of anterior and posterior composite resins. Silux and P30 exhibited greatest variation within the pairs. Prisma Bond produced highest smoothness on posterior composites were as Mylar strips on anterior composites. This study suggested that surface roughness can be determined by both characteristics of polishing agents and properties of composite resin. Due to difference in size shape and number of filler particles different surface roughness was created using identical instruments on different composite resins. The vivadent polisher produced the smoothest surface of the rubber points. Moore’s disks created a surface similar to that of both Mylar and Prisma Bond application.6
Effectiveness of three polishing systems on surface roughness of four hybrid composites was conducted using profilometer and scanning electron microscope. They were Pertac, APH, Herculite, Z100. Three polishing systems used were 1)Enhance polishing Kit 2)Kerr finishing kit 3) MFS/MPS ESPE polishing kit. Total 48 hybrid samples were prepared. Four composite samples per polishing systems. Composites were compressed in 20×1mm ring with 2 glass slabs. This was cured on each side for 30 sec with visible light cure. It was stored for 45 min in 37 degree Celsius water bath. Samples were then randomly assigned to one of the four test groups, finished and polished by a single investigator using three different polishing techniques. Scanning electron microscope and profilometry evaluation demonstrated that MFS/MPS system gave superior polish for Z100, Herculite and Pertac composites. Kerr system polished APH with best results. Enhance polishing system gave poorest polish to all composites.4
Evaluation of surface roughness of two polished composites, Filtek Z250 and PertacII aplitip using 3D profilometry was done. Four clinically acceptable finishing techniques were used. 1) Arkansas stone 2)sof-lex aluminium oxide discs 3)Diamond points 4)Silicone points. Total 60 specimens of composites were made in polytetraethylene split mold. Thirty for each material. Each specimen were polymerised for 50sec with visible light polymerizing unit. These specimens were divided into five groups and each group was finished with different finishing agents. A 3D profilometer was employed to measure surface roughness parameters. They concluded that surface roughness of Pertac was lower than Filtek Z 250.Microhybrid composite Filtek Z250 exhibited more surface roughness than Pertac. Based on polishing systems used diamond points and sof-lex aluminium oxide discs were more suitable for polishing than silicon points and Arkansas stone.3
Analysis of surface roughness of five novel resin composites containing nanoparticles was done. They were Ceram X, Filtek supreme XT, Grandio, Premise and Tetric-evo-ceram. A total of 100 sample discs were fabricated 20 per resin, cured under Mylar strips, polished using three different polishing system. Pogo, optrapol and one glass. Disc surface roughness was evaluated under scanning electron microscope. Effectiveness of polishing system seems to be material dependent. For Grandio and Filtek supreme XT, Pogo created equal smooth surface. Tetric evo ceram exhibited roughest surface with optrapol. According to SEM images, Optrapol and one glass scratched and plucked particles away from surface. While Pogo created a uniform finish, although roughness values were not the same for each composite.10
A study was conducted to compare surface roughness and texture of polished nanofill and nanohybrid resin composites. In this study polishability of one nanofill (Filtek supreme XT) and three nanohybrid composites (grandio, Tetric evo ceram and venus diamond) was investigated using surface profilometry and scanning electron microscope. After specimens were cured under Mylar strips or preground with 600-grit silicon carbide paper, three polishing systems were applied and their polishing effects were compared using 1) diamond polishing points 2) Diamond paste 3) Aluminium oxide discs. Surface texture of polished nanofill Filtek supreme XT and nanohybrid Tetric-N-ceram were uniformly smooth than the other two when assessed under profilometer and scanning electron microscope.2
Comparison of polishability of silorane based composite (Filtek p90), a nanohybrid composite (Tetric-N-ceram) and Hybrid resin composite (TE economy plus) was done. They were polished using Shofu super snap polishing kit. Then surface roughness was assessed using profilometer and scanning electron microscope. Silorane based resin exhibited a surface roughness of 0.24 µm. Surface roughness of (Ra value) o.2 microns is ideal threshold, hence clinically acceptable, beyond which plaque accumulation takes place. Results of study showed that silorane based and hybrid based resin composites exhibited similar surface roughness. Nanohybrid on the contrary exhibited unacceptable surface roughness of 0.34µm.5
6.3 Aim and Objectives of study
Aim
To evaluate and compare surface texture and roughness of two nanohybrid (Filtek Z250-XT & Tetric–N-ceram bulkfiller) and one nanofill composite (Ceram X Duo) using profilometer and Scanning electron microscope.
Objectives of study
1. To evaluate the surface roughness of Filtek Z250-XT using three polishing agents :
a) Multi Enhance finishing and polishing system
b) Super snap Shofu finishing and polishing kit
c) Sof-lex discs using profilometer and scanning electron microscope.
2. To evaluate the surface roughness of Tetric-N-ceram bulkfiller using three polishing agents:
a) Multi Enhance finishing and polishing system
b) Super snap shofu finishing and polishing kit
c) Sof-lex discs using profilometer and scanning electron microscope.
3. To evaluate the surface roughness of Ceram X Duo using three polishing agents :
a) Multi Enhance finishing and polishing system
b) Super snap shofu finishing and polishing kit
c) Sof-lex discs using profilometer and scanning electron microscope.
4. To compare the above mentioned groups.
7. MATERIALS AND METHODS
7.1 Source of data
Three different composite materials and three different finishing and polishing agents will be selected for the study. They are Filtek Z250-XT, Tetric-N- ceram bulkfiller and Ceram X Duo. Three polishing agents are Multi enhance, super snap shofu and sof-lex discs. The study will be done using profilometer and scanning electron microscope at National Institute of Technology, Karnataka at Surathkal.
7.2 Method of collection of data
Specimen preparation
Sixty three resin composite disks will be prepared in rectangular acrylic mold (8×2mm) dimension, with 4mm thickness. It will be placed between the two Mylar strips and sandwiched between glass slides. The molds will be bulk-filled to slight excess and pressed and the flush will be removed with a top glass slide. It will be cured with Smart Lite PS 230V of Dentsply. It is a blue LED unit with a light intensity of 950mW/cm2 for 20 seconds in a wiping mode, from front and back of the specimens. Light –cured resin composite specimens will be pushed out of their molds and stored at ambient atmosphere for a maximum of 1 hour before initial surface roughness determination. Reverse side of the disk will be abraded with 600-grit silicon carbide abrasive under running water. From each of three composites and for each of the three polishing systems, the specimens will be prepared accordingly.
Group A (Filtek Z250XT) : Out of 21 samples of Filtek Z250,
1. 7 specimens will be polished with multi enhance polishing agents.
2. 7 specimens will be polished with Super snap Shofu polishing agents.
3. 7 specimens will be polished with sof-lex discs.
Group B (Tetric-N-Ceram bulkfill) : Out of 21 samples of Tetric-N-ceram,
1. 7 specimens will be polished with multi enhance polishing agents.
2. 7 specimens will be polished with Super snap Shofu polishing agents.
3. 7 specimens will be polished with sof-lex discs.
Group C (Ceram X Duo): Out of 21 samples of Ceram X Duo,
1. 7 specimens will be polished with multi enhance polishing agents.
2. 7 specimens will be polished with super snap Shofu polishing agents.
3. 7 specimens will be polished with sof-lex discs.
Three types of composites are: Filtek Z250XT(3M ESPE), Tetric-N- ceram bulkfiller (IVOCLAR VIVADENT), ceram X Duo(DENTSPLY).
Filtek Z250 XT (3M ESPE): It is a nanohyrid universal composite designed for use in both anterior and posterior restorations. Available in 12 different shades. It contains (Bis-GMA) Bisphenol A and glycidal methacrylate. Silica filler particles are large and irregular (0.2 -1 microns) compared to nanofill composite. Hence exhibit good mechanical properties but limited in esthetics and polishability.
Tetric-N-Ceram bulkfill (IVOCLAR VIVADENT): It is a unique nanohybrid composite developed specially for the fast, efficient ‘bulk placement’. It is placed in the cavity with one layer bulk upto 4mm in thickness. Light activator Ivocerin present in material ensures complete cure of the filling. Hence greater depth of cure with larger increments. So can be placed even in deep cavities and can be cured to the entire depth. Available in three different shades IV-A, IV-B, IV-W.
Ceram X Duo(Dentsply): It is a nanofill resin composite with dual translucency shading concept suitable for both anterior and posterior teeth. It is a nano ceramic composite with natural enamel and dentin shades. Four shades of dentin and three shades of enamel provides natural esthetics, improved polishability and long term gloss. A high filler loading of nano sized particles offers good strength and esthetics.
* Three polishing systems: Super snap Shofu, Multi enhance(Dentsply),Sof-lex discs(3M ESPE).
Super snap finishing and polishing system (Shofu): Available in different colour coded system and four colour grits. Black grit contains course abrasive particles used for contouring the restoration. Violet colour contains medium abrasives used for finishing the restorations. Green grits have fine abrasives used for polishing. Red colour grits contain superfine abrasives used for final polishing.
Multi enhance finishing and polishing system (Dentsply): It is suitable for all types of resin restorations. Finishing points are in the form of disks and cups containing aluminium oxide abrasive crystals. Final polishing is done with polishing cups in conjunction with Prisma gloss polishing paste which contains fine aluminium oxide crystals.
Sof-lex finishing and polishing system(3M ESPE): They are colour coded disks with small round eyelet that snaps into the mandrel. Discs are urethane coated paper containing aluminium oxide abrasives ranging from coarse, medium, fine to super fine. Black colour denotes coarse discs, dark blue for medium, blue for fine and light blue for superfine.
4.ARMAMENTARIUM AND MATERIALS
· Three types of composites: Filtek Z250XT(3M ESPE), Tetric-N- ceram bulkfiller (IVOCLAR VIVADENT), ceram X Duo(DENTSPLY).
· Three polishing systems: Super snap Shofu, Multi enhance(Dentsply), Sof-lex discs(3M ESPE).
· Light curing unit
· Glass slides
· Mylar strips
· Rectangular acrylic mold (8×2×4)mm dimension
· 600 Grit Silicon carbide paper
· Contra angled Handpiece
· Scanning electron microscope
· Profilometer SJ 301.