1DCT 1Specialty
The Leeds Teaching Hospitals NHS Trust
1a, Asmaa 2ain 2StRDennis 3Professor in Restorative Dentistry, in Restorative Dentistry,Al-Taie Dental Materials Leeds Thomas , David Wood a3a
Dental Institute
Dentist in Restorative Dentistry, 2 Lecturer / StR in Restorative Dentistry, 3Professor in Dental Materials a Leeds Dental Institute /School of Dentistry, University of Leeds.
Thomas Dennis 1a, Asmaa Al-taie 2a, David Wood 3a .
Introduction
Nano- lled and nano-hybrid resin composites allow a high surface polish to be gained and retained after placement. Decreased surface roughness prevents plaque and stain retention, improves aesthetics and increases the wear resistance of the restoration. A mean surface roughness (Ra) below 0.2μm is regarded as an acceptable standard for a restoration. Although conventional polishing systems provide acceptable surface properties, they are time consuming to perform. In more recent times single and reduced-step polishing regimes have been introduced with claims of similar/superior outcomes. Type to enter text
Method
Three composites were used to create 2mm x 10mm cylindrical samples (n=150) [ISO Standard 4049]. Samples were nished with 1200 grit silicon carbide paper and then randomly assigned to the polishing groups outlined below (n=30). Each sample was polished for 30 seconds per step by a single operator. White light pro lometry was used to assess mean surface roughness (Ra). Surface gloss testing was performed with a small area 60° glossmeter. Representative samples from each group were analysed using a Scanning Electron Microscope. 1:1 macro photo analysis was performed with a DSLR camera.
Results & Discussion
Sof-Lex XT, Prisma cup and DiaPolisher paste 3M
Polishe e Kenda
5 Steps 150 secs Control
2 steps 60 secs P1
DIATECH ShapeGuard Coltene
Op 1step Kerr
2 steps 60 secs P2
1 step 30 secs P3
OneGloss Shofu
1 step 30 secs P4
100 90 80 70 60 50 40 30 20 10 0
Filler par cle Size (μm)
Filler Volume
Nano-hybrid composite
0.004-0.1
58.4%
Essen a®
Micro lled hybrid composite
0.016-10
65%
BRILLIANT EverglowTM
Nano-hybrid composite
0.02-1.5
56%
Resin Composite
Composite type
FiltekTM Universal Restora ve
Qualitative Analysis
Surface Gloss (Gu)
P2
P4
Increased Lustre
C
C 1
Untitled 1
P1 2
P2 3
P3 4
P4 5
Mean Surface Roughness (μm ) 0.30 Decreased Roughness
0.25 0.20 0.15 0.10 0.05 0.00
1
Untitled 1
C
2
P1
3
P2
4
P3
P4
P2
5
P4
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Signi cant di erences were seen between the groups’ surface roughness (p<0.05). P4 > P3 > C > P1 > P2. The lowest surface roughness was (0.08 Ra) was seen with a 2 step system (P2) on Everglow composite, both created by the same manufacturer. Polishing with P4 resulted in highest surface roughness to an unacceptable clinical standard (p<0.05). P1 and P2 resulted in highest gloss in all composite groups (p<0.05). The highest gloss values were obtained when Everglow composite was polished with P1 (96.70 GU) and P2 (90.68). We noted a negative correlation between surface gloss and roughness r = 0.7 (p<0.05). SEM analysis reinforced our quantitive ndings with homogenous nishes seen in well performing protocols and deep grooving, ller pull-out and scratches noted with P4. Photographic analysis showed evident di erences in the perceived shade and optical properties of the composite surfaces polished with di erent protocols. The null hypothesis was rejected as some reduced-step polishing systems can equal and indeed out perform the control multi-step system tested. ti
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Comparison of reduced-step vs multiple-step composite polishing systems on composite surface properties: an in-vitro study.