THE EFFECT OF DIFFERENT POLISHING SYSTEM ON THE SURFACE . - Weebly

Official Publication of Orofacial Chronicle, Indiawww.jhnps.weebly.comORIGINAL ARTICLETHE EFFECT OF DIFFERENT POLISHING SYSTEMON THE SURFACE ROUGHNESS OFCOMPOSITE MATERIALSGurinderjeet Singh Gulati MDS 1, Namrata Kaur Gulati (MDS) 21- Reader ; 2- Postgraduate Resident.1- Department of Conservative Dentistry and Endodontics, Rishiraj Dental College & Hospital ,Gandhi Nagar, Bhopal, M.P., India.2- Department of Oral Pathology, Rishiraj Dental College & Hospital , Gandhi Nagar, Bhopal, M.P.,IndiaABSTRACT:The search for an ideal polishing agent for dental composite is ongoing.Several polishing tools have been used over the years ranging from multiplestep system using fine and super fine diamond finishing burs, abrasive disks,diamond and silicon impregnated soft rubber cups, to one step polishingsystem. The present study evaluates two polishing system i.e SofLex (multistep polishing system) and PoGo (single-step polishing system) on a compositematerial namely Filtek Z-100.Key Words: Z-100, Sof-lex, PoGo, Profilometer.54

Cite this Article: G.S Gulati, Namrata K Gulati, The effect of different polishing system on thesurface roughness of a composite materials : Journal of Head & Neck physicians and surgeons Vol 2,Issue 2, 2014 : Pg 54-64INTRODUCTION:The search for an ideal polishing agent for dental composite is ongoing. Severalpolishing tools have been used over the years ranging from multiple step s ystemusing fine and super fine diamond finishing burs, abrasive disks, diamond andsilicon impregnated soft rubber cups, to one step polishing system. The presentstud y evaluates two polishing s ystem i.eSofLex(Figure.1)(multi-steppolishings ystem) and PoGo (Figure.2) (single-steppolishing s ystem). Sof-Lex is an aluminumoxide abrasive manufactured from bauxite,as impure aluminum oxide and available asvarious particle sizes. The particles areFigure.1:Soflexapplied to paper disks in coarse, mediumfine and extra-fine grits. It has reversiblediscs, which makes aligning disc easier forpolishing various surfaces and are flexible.PoGo Polishers are pre -mounted single anepolishingdevicesdesigned for use in final polishing of allcomposite restorations. Advantage of theFigure.2: POGOone-step s ystem is the convenience and efficiency of producing a very smoothsurface without having to switch to finer polishing items or having to wash anddry between each step to ensure removal of the larger abrasives from theprevious step. 155

Z100 composite (Micro-h ybrid) restorative material is visible-light activated,radiopaque, restorative composite silica. The inorganic filler loadingis 66% b y volume with a particle size rangeof3.5to0.01micron.Z100restorativecontains BIS-GMA and TEGDMA resins.Theadvantagesarelowpol ymerizationshrinkage, high fracture resistance, and highwear resistance. The present stud y evaluatedFigure.3:Filtek Z-100two polishing s ystems that is Sof-lex andPoGo ,on the surface of an aesthetic material namel y Filtek Z-100(Figure.3).MATERIAL AND METHOD:This present stud y was carried out in the Department Of ConservativeDentistry and Endodontics, Krishnadevraya college ofhospitaldental sciences andin collaboration with Department Of Mechanical EngineeringIndianInstitute Of Sciences, Bangalore.Materials used in this studyResinCompositionShadeCompositeZ100BIS-GMA andTEGDMAA-2Mean ParticleWeight % ofSizeMineral FillerZirconium84.5%silicate0.6microns56

Polishing SystemCompositionUsageSof-LexAluminium oxide discDryCoarse4 strokesMedium4 strokesFine4 strokesUltra fine4 strokesDiamond coated micro-polisherDry, 16 strokesPoGoA total of 20 specimens were made.Specimen were made of light activatedresin composite Z-100, approximatel y 3mm in diameter and 2mm in height. Thespecimens were prepared from a stainless steel mold. The composite was filledwith a composite filling hand instrument. The mold was slightl y overfilled withcomposite resin and a M ylar strip was placed on both sides of the mold. Thecomposite resin was sandwiched between two glass plates to extrude the excessmaterial. The ex cess material was then removed.The composite resin was cured with a light curing unit for 40 seconds onboth sides of the mold through the glass plates to standardize curing distance(1.35mm). Light intensit y of the curing unit was standardized to 400mW/cm 2using a light intensity meter (radiometer). The intensit y of light was checkedbefore every use with a radiometer. The resin blocks were finished to a uniformsurface using carbide bur at a speed of 15,000 rpm to create surfaceirregularities. The surfaces were finished for 10 seconds each. In this way allthe blocks were prepared to a standard surface. Now all the blocks were equall ydivided into two groups for final polishing. One group of 10 blocks waspolished with Sof-Lex and another group of 10 Blocks was polished with PoGo.57

Polishing Procedure10 samples were polished with SofSof-LexLex and 10 samples were polished with PoGo. ForFo Sof-Lexthe disks in the kit were attached by a metal hub to the autoclavable metal mandrel. The coarsegrit disk was used for gross reduction at medium speed of 10,000 rpm. The medium grit disk wasused for gross contouring at medium speed of 10,000 rprpmm for 15 to 20 seconds. The fine grit discwas used to finish at higher speeds of 30,000 rpm for 15 to 20 seconds. The superfine grit wasused to polish at high speed of 30,000 rpm for 15 to 20 seconds. In total 10 samples werepolished with Sof-Lex, rest of the 10 samples werepolished with Diamond abrasive (PoGo) which was aone step polishing system. The polishing was done at aspeed of 20,000 rpm. After the specimens were polished,the specimens were analyzed for surface roughnessusing a two dimensionall surface profilometer at theIndian Institute Of Science, Bangalore. The RoughnessFigure.4average (Ra) of a specimenmen was defidefined as the arithmeticaverage height of roughness component irregularities from the mean line measured within thesampling length. The diamondamond stylus had a diameter of 2 microns . Profilometer (Figure.4)readings were made at the centre of each specimen, and the numerical average was determinedfor each gital readout of average surface roughness(Ra) in microns. The average roughnessvalue represents the arithmetic mean of theheight of all surface irregularities over eterspecimen. Results were tabulated and the ANOVA TEST was used to determinethe significant differences in microleakage between the groups. A PP value of0.05 or less was considered as statistical significance.58

Table IRoughness Average (Ra)Of Sof-Lex and PoGoGROUP (Filtek Z-100)S.NoAverage (Sof-lex)Average 26.217.2287.227.2358.204.2299.198.20610.211.239The results were evaluated statistically by ANOVA TEST.Mean roughness in Group 1 was 0.2283 with standard deviation .0122Mean roughness in Group 2 was0.1853 with standard deviation 0.007Maximum mean roughness was seen with Group 1.59

Results of one-way ANOVA test for surface roughness showed P .000 which is statisticallysignificant. Pair wise significance showed:GROUPP-VALUEGroup I Vs Group 2P 0.000Statistically SignificantDISCUSSION:Instrument designed to contour dental restorations must be sufficientl y abrasiveto establish the final geometry, conversely, the least abrasive rotary instrumentthat adequatel y establishes contour should be used to leave the smoothestsurface. 2 Finishing and polishing devices, materials, and procedures areintended to produce intentional, selective and controlled wear of dentalrestorative material surfaces. The wear mechanism is the transfer of energy withremoval or displacement of material. In polishing with abrasive particles, thewear mechanism is mostl y abrasive wear, but other mechanisms are alsopossible. These include surface fatigue and the development of ploughinggrooves or scratches.There are two types of abrasive wear modes, i.e. two-body abrasion and three body abrasion. In atwo-body mode, the bound abrasive particles is solidly fixed to the substrate. In the three-bodymode, free (or loose) particle slurry between the specimen surface to be polished and a flatpolishing substrate. In this study two-body mode abrasion was used.1 Since improper applicationof different polishing systems could lead to decrease effectiveness strict adherences tomanufacturers instruction on polishing procedures were followed. In this study one operatorperformed all the finishing and polishing procedure to simulate clinical procedure and to reducethe variation of the force used on the specimen. A previous study showed that dry finishing ofcomposites was superior or equal to produce a smooth surface, so a dry condition was chosen.3This was also in accordance to manufacturer’s instructions. The number of strokes as well as thehand piece speed were also standardized so that the variation of the roughness average valuecould be kept to a minimum. The results were analyzed using ANOVA test. Descriptive datapresented as numbers with corresponding surface roughness scores for each group. The ANOVA60

test was used to determine the significant differences in roughness average between the groups.A P- value of 0.05 or less was considered as statistically significant. When the comparisonwas done between the two polishing s ystems Sof-Lex gave statisticall ysignificant better polish than PoGo.Hardness determines the degree of deformation of a material and it is generall yaccepted as an important propert y and a valuable parameter of comparison withthe tooth structure. 4 Changes in hardness may reflect the state of cure of amaterial and the presence of an on-going reaction or maturit y of the restorativematerial. 5 To assure an optimized clinical performance of restorations, it is ofparamount importance to emplo y materials with hardness at least similar to thatof the dentinal substrate, not onl y superficiall y, but also in depth, since anaccentuated decrease in hardness would adversel y affect their mechanicalproperties and marginal integrit y. 4 The incorporation of softer filler particleswith hardness characteristics similar to that of enamel appears to result indecreased wear. It is thought that soft particles are more capable than hardparticles of absorbing energy generated during the masticatory process, thereb ytransmitting lower stresses to the matrix. 5Correlation to clinical practice may be limited to situations where accessible relatively flatsurface are finished. Further studies are needed to determine which polishing technique are bestsuited to clinical situation where access is limited and restoration surfaces are not flat. Studiesshould be done in combination with Scanning Electron Microscope more valid predictions ofstudy values can be made.CONCLUSION:Following conclusions were drawn from this stud y that the statistical anal ysisshows that all materials i.e. Z100 (0.2129) and Esthet-X (0.1206) showed leastroughness average with Sof-Lex when compared to PoGo. Therefore Sof-Lexshould be used as preferable polishing s ystem as it shows better result.61

REFERENCES:1. Jefferies.S. Abrasive finishing and polishing in restorative dentist y: Astate of the art review. Dent Clin N Am 51 (2007) 379-397.2. Silvia Helena, Regia Luzia, Maria Fidela de Lima Navarro, OsvaldoBenoni. Effect of different finishing and polishing techniques on thesurface roughness of microfilled, h ybrid and packable composite resins.(2005) Braz Den J ;16 (1); 39-44.3. Robert A. Freitas, JR. Nanodentistry.J ADA (2000) Vol 131; 1559-15654. Kenneth J. Anusavice and Sibel A. Antonson. Finishing and polishingmaterials. Science of dental materials. 11th edition.5. Cecilia P.Turssi, Jack L.Ferracane, Monica C.Serra : Abrasive wear ofresin composites as related to finishing and polishing procedures. DentMater 2005; 21;641-648.Acknowledgement- NoneSource of Funding- NilConflict of Interest- None DeclaredEthical Approval- Not RequiredCorrespondence Address :DR. G.S.GULATI,93 MALVIYA NAGAR, BEHIND AIRTEL BUILDING,BHOPAL(M.P)-462003PHONE NO:- 942500591962

Z100 composite (Micro-hybrid) restorative material is visible-light activated, radiopaque, restorative composite restorations. . The composite resin was cured with a light curing unit for 40 seconds on both sides of the mold through the glass plates to standardize curing distance (1.35mm). .