Year : 2005 | Volume
: 8 | Issue : 1 | Page : 60--66
Surface finish of esthetic materials - an in-vitro SEM study
Promila Verma, KK Wadhwani, Kapil Loomba
Department of Operative Dentistry, U.P. King George's University of Dental Sciences, Lucknow, India
Department of Operative Dentistry, U.P. King George«SQ»s University of Dental Sciences, Lucknow
Proper finishing and polishing of tooth coloured restoration enhances the esthetics and longevity of restored teeth. Plaque retention, surface discoloration and esthetics of the restoration have been related to the smoothness of the restoration surfaces. This study was done to evaluate the amount of surface smoothness produced after the use of various finishing and polishing devices on restoration.
The first article of this series of taro articles discusses the effect of various finishing devices on light cure composite (sure fit) while second article is on compomer and comparison of both the groups.
|How to cite this article:|
Verma P, Wadhwani K K, Loomba K. Surface finish of esthetic materials - an in-vitro SEM study.J Conserv Dent 2005;8:60-66
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Verma P, Wadhwani K K, Loomba K. Surface finish of esthetic materials - an in-vitro SEM study. J Conserv Dent [serial online] 2005 [cited 2020 Feb 21 ];8:60-66
Available from: http://www.jcd.org.in/text.asp?2005/8/1/60/42704
Esthetics has always played a significant role in individual's life right from time immemorial. Although individual perceptions about esthetics have changed over a period of centuries, yet its role in any individual's life cannot be underestimated. In the overall personality presentation of an individual, his face, his smile and teeth in particular have an important role. Naturally, then stress has been placed on improving the over all face value. The modern beauty contests are a proof and witness to this.
The term "esthetics" denotes beauty' as distinguished from merely pleasing. Thus in dentistry esthetics is that portion of the discipline that deals with retaining or achieving the ultimate in appearance. The esthetic concern in dentistry is to try to convince a viewer that there is no restoration in the tooth.
The search for an ideal esthetic material for conservative restoration has resulted in improvement in materials and technique, particularly in recent years. This led to the invention of composite by Bowen in 1962 and Glass lonomer by Wilson & Kent in 1972.
Surefil is a high-density posterior restorative material and has been designed for stress bearing restoration. This is one component visible light cured restorative materials. The manufacturers claim that it has got metamoristic quality, due to which it takes on the surrounding tooth color and reflects light much like tooth structure. The visual appearance of the surface of a finished composite is frequently a reflection of the instrument system employed. Various finishing and polishing devices have been used in the past to finish the tooth color restorative materials. Tungsten carbide, diamond burs, polishing disc, strips, stones, steels bur (AC. McCundie. F.D. Murray 1974) E.T. carbide burs, soflex disc, white stone, Quasit rubber point, lustre polishing paste (DH Pratten, G.H. Johnson 1988) are some included for this purpose.
The effect of various finishing instrument on surface roughness has been studied, but with varying results. The variation is due to diversity in size, shape, composition and distribution of filler particles in commercial composite and the wide variety of finishing instruments.
Materials and Methods
Thirty-Six recently extracted teeth were collected. They were cleaned free of calculus and debris with scalers and stored in normal saline at room temperature when not in use. Class- V cavities were prepared with the help of diamond burs and a] rotor. A calibrated right angle probe was used to measure the depth of the cavity at 1.25mm so as to make nearly the same size of the cavity so as to minimize variables. They were divided into two groups as shown in [Table 1]
Total 36 Samples - Group-I-16 Samples-(Surefil)/Group-I-16 Samples-(Compomer)
Group-I : 18 class- V cavities were filled with surefil in this group. These samples were further divided into three sub-groups according to time of storage as shown in [Table 2].
Consisted of 6 samples and was stored in airtight container for 24 hours. These samples were further subdivided as AI A2 and A3 with two samples in each sub-division.
A 1 : Samples were finished with fine grit diamond bur and one sample was later polished with Instagloss polishing paste with the help of micromotor and rubber cup.
A 2 : Samples of this sub-division was finished with the help of finishing point and later one sample was polished with polishing paste
A 3 : Finishing disc was used to finish the samples of this sub-division. One sample was left as such the other was further polished using Instagloss polishing paste.
Six samples of this sub-group were stored for 48 hours. They were further subdivided into 3 sub-division on the basis of finishing instrument used with two samples in each subdivision.
B 1 :Two samples were finished with diamond bur of fine grit. One sample was left as s u c h and other was polished with Instagloss polishing paste.
B 2 : Finishing was done with finishing point in this sub-division and one sample was further polished using Instagloss polishing paste
B 3 : Samples were finished with fine grit finishing disc and one samples was further polished with polishing paste.
Six sample were stored for seven days and then finished withdifferent finishing instrument.
C 1 :Two samples finished with fine grit diamond finishing bur. One samples then left as such and other was subjected to polishing with Instagloss polishing paste.
C 2 : Finishing point of fine grit was used for finishing of the samples and after that one samples was left unpolished and other samples was polished utilizing polishing paste.
C 3 : Here also two samples were taken and were finished with fine grit finishing disc and here also one sample was left as such and other were polished with Instagloss paste.
After finishing and polishing, these samples were scanned as a whole with the help of SEM. Then photomicrographs of areas of interest were taken at x 120 and x 500 magnification.
These photomicrograph were then evaluated comparatively for unbiased statistical analysis. For this three persons unaware of this technique used for finishing and polishing were given the photomicrographs and they evaluated them on a scale of 1 to 5, where:
1 = Smoothest surface of the prepared sample as observed on' photographs.
5 = Roughest surface of the prepared sample as observed on photographs.
In [Table 1] we can observe that diamond-finishing bur has recorded the highest value with out the use of paste at i.e., 4.83 ± 0.24 and min value was recorded with sotlex finishing disk with paste i.e., 1.0 ± 0.0.
In [Table 3] it was observed that `t' values of nearly all the compared time period was insignificant. Thus there is a insignificant effect of time on the roughness hence the surface topography does not seem to be influenced by time.
One of the most important factors in esthetic restoration is finishing and polishing. Proper finishing and polishing of restoration enhances both esthetic and longevity of the restored teeth. Residual surface roughness associated with improper finishing and polishing of dental restoration can result in a number of clinical difficulties for both patient and dentist. These problems include plaque accumulation, gingival irritation, surface staining and poor appearance of the restored teeth.
In this study it was observed that surface roughness was higher in the samples, which were finished with diamond finishing bur. The surface demonstrated resin matrix crazing and significantly higher filler particle loss as compared with finishing point and finishing disk. There was no statistical difference in the samples at different time intervals compared.
AC Mclundie & Murray (1974) also supported this view. Their studies concluded that diamond-finishing bur were effective at removing resin material, but none provided "a surface that would be clinically acceptable". The particles of diamond left grooves in the surface, regardless of the speed at which the bur was revolving.
Composite surface roughness is usually considered to be dictated by the size, hardness and amount of filler material. The revolving finishing instrument when comes in contact with the composite or any restorative materials surface, initially removes the gross filler particles, hanging out of surface of the restoration, as a process of finishing/polishing procedure. If the filler particles are bigger or if the binder used is not so proper then rougher surface may result as a consequence of removal of the loose filler particles. However if the binder is strong and smaller filler particles are used, then, even on contact of revolving finishing instruments there would be minimal abrading and there by the surface would remain relatively free of roughness and production f valley like depression, hence the surface would be smooth naturally and would result in excellent finished surface.
MJ Ashe, GA Tripp (1996) and North East SE, Van Noort (1988) also agree that diamond finishing burs produces the roughest surface. They concluded that diamond finishing bur often had rough, abraded valleys surrounded by more smoothly polished raised areas. They also agreed that diamond finishing bur were capable of removing composite material rapidly and therefore they are used for gross contouring and finishing of composite material.
In the present study also, we found increased surface roughness with the usage of diamond finishing bur as compared to disc and finishing points.
Finishing point which as used in this study for finishing of light cure composite (surefil) exhibited smoother surface as compared to that of diamond finishing bur. Soflex finishing disk produced the best surface finish. R V Noort and LG Davis (1984) also concluded in their study that finishing disk provided smoothest surface.
Light cure composite exhibited smoothest surface when it was further subjected to polishing with instagloss polishing paste. Fine scratches, which were produced by the finishing device, were removed and the surface appeared smooth. Thus in this study it was observed that finishing disk can be used to finished the esthetic material successfully.[Figure 1],[Figure 2],[Figure 3],[Figure 4],[Figure 5],[Figrue 6]
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