Int Poster J Dent Oral Med 2006, Vol 8 No 04, Poster 340
A comparison of the surface quality of provisional crowns after chairside polish
Dr. Arne F. Boeckler, Prof. Dr. Jürgen M. Setz
Martin-Luther-University Halle-Wittenberg, Department of Prosthodontics
05. - 08. 04. 2002
International Association of Dental Research (IADR), 80th General Session & Exibition
San Diego, California, USA
Poor surface quality of provisional crowns affect plaque adhesion and contributes to gingival inflammation. Polishing temporary restorations in the dental lab is the gold standard and gives excellent surface quality but is time consuming and has the risk of cross contamination due to contaminated pumice.
Aim of this study was to describe the surface quality of four resins for provisional crowns after chairside polish with four recently developed polishing devices. The results are compared with the surface quality after polish using dental lab technology.
Material and Methods
One hundred specimens of three self curing isobutyl-methacrylate materials (Dentalon Plus, Heraeus Kulzer Ltd.-Germany; Trim, H. J. Bosworth Company_USA; Snap, Roeko Ltd-Germany) and of one bis-acryl composite material (ProTempGarant, 3MEspe Dental Corporation-Germany) were made according to the manufacturer's instructions. After polymerization they were ground with a diamond disk to produce a uniform and standardised initial surface quality. The specimens were then polished chairside as recommended by the manufacturers using a standardized procedure. By polishing in the dental lab a rag wheel with pumice and polishing compound was used. Three polishing devices including several combinations of rubber polishers (Bredent Dental Products-Germany, Hager und Meisinger Ltd.-Germany, Busch und Co. Ltd.-Germany) and one polishing device including different diamond rotary instruments, which were developed for the polish and finish of direct composite restorations (Intensiv Ltd.-Switzerland) were tested (Fig 1). The surfaces before and after treatment were investigated using contact stylus technique (mean roughness average - Ra) and SEM (Fig 2,3). Three measurings on each specimen were made. Differences were statistically tested for significance by Kruskal-Wallace-Test and Man-Whitney-Test (p<0.05) with a Bonferroni-adjustment.
|Fig 1 Tested polishing devices
|Fig 2 Surface roughness profile (Ra): Dentalon Plus
|Fig 3 SEM: Dentalon Plus (enlargement x 500, 3 kv)
Chairside polish improved the surface quality in all specimens (Bredent: DeltaRa 2.2-1.5 µm; Meisinger DeltaRa 1.66-1.3 µm; Busch DeltaRa 1.59-1.07 µm; Intensiv DeltaRa 1.12-0.86 µm). There were important differences between the surface qualities of dental lab polish and chairside devices in all acrylic materials (Fig 4-6) which could not be found so obviously in the tested composite material (Fig 7). Dental lab polish provided by far the best results. The differences within the three rubber devices were not so obvious, but there was a slight tendence to better results with the Bredent- equipment. Surprisingly, in one resin (TrimTM) rubber polisher produced similar improvements as polishing in the dental lab. Further investigations about this finding are necessary. The diamond rotary device produced the roughest surface in nearly all materials.
|Fig 4 Improvement of the surface quality after polishing: Dentalon Plus
||Fig 5 Improvement of the surface quality after polishing: Snap
|Fig 6 Improvement of the surface quality after polishing: Trim
||Fig 7 Improvement of the surface quality after polishing: ProTemp Garant
Dental lab polish still gives the best surface quality in fairly all materials. There are differences between several chairside devices. However, the rubber polishing devices produce an acceptable surface quality for short term applications of provisional crowns. Diamond rotary instruments developed for composite finishing produced inferior surface qualities with the tested acrylic materials.
This Poster was submitted by Dr. Arne F. Boeckler.
Dr. Arne F. Boeckler
Department of Prosthodontics
Grosse Steinstrasse 19
06108 Halle (Saale)