Effect of dentin surface roughness on the shear bond strength of resin bonded restorations

Abstract

PURPOSEThis study aimed to investigate whether dentin surface preparation with diamond rotary instruments of different grit sizes affects the shear bond strength of resin-bonded restorations.MATERIALS AND METHODSThe buccal enamel of 60 maxillary central incisors was removed with a low speed diamond saw and wet ground with silicon carbide papers. The polished surfaces of the teeth were prepared with four groups of rotary diamond burs with super-coarse (SC), coarse (C), medium (M), and fine (F) grit sizes. Following surface preparation, 60 restorations were casted with nickel-chromium alloy and bonded with Panavia cement. To assess the shear bond strength, the samples were mounted on a universal testing machine and an axial load was applied along the cement-restoration interface at the crosshead speed of 0.5 mm/min. The acquired data was analyzed with one way ANOVA and Tukey post hoc test (α=.05).RESULTSThe mean ± SD shear bond strengths (in MPa) of the study groups were 17.75 ± 1.41 for SC, 13.82 ± 1.13 for C, 10.40 ± 1.45 for M, and 7.13 ± 1.18 for F. Statistical analysis revealed the significant difference among the study groups such that the value for group SC was significantly higher than that for group F (P<.001).CONCLUSIONDentin surface roughness created by diamond burs of different grit sizes considerably influences the shear bond strength of resin bonded restorations.

Silicon‐based film on the yttria‐stabilized tetragonal zirconia polycrystal: Surface and shear bond strength analysis

“…It seems reasonable to assume that Silva et al are correct to expect that a rougher surface provides an additional micromechanical retentive pattern due to the increase in surface area. Increasing surface through managing the surface roughness is a technique to improve the retention . A long‐lasting bond depends on micromechanical interlocking generated by surface roughening and chemical adhesion between the cement and ceramic .…”

“…Increasing surface through managing the surface roughness is a technique to improve the retention. 21 A longlasting bond depends on micromechanical interlocking generated by surface roughening and chemical adhesion between the cement and ceramic. 22 The highest Ra values we observed occurred in the group that was sandblasted and coated with the Si-based film (SiFSG The Si-based film decreased the contact angle on the surfaces tested.…”

What is the changing frequency of diamond burs?

“…It was stated in the literature that preparation technique could affect the retention of the fixed prosthesis. 15 16 17 34 In addition, McInnes 18 and Al-Omari 34 stated that surface roughness is important especially for the cementation of full crowns with non-adhesive zinc phosphate luting cement, as the luting is achieved from mechanical interlocking. 18 34 Also, the study of Solá-Ruiz et al 19 presented that in porcelain laminate preparation, oscillated instruments produced a rougher dentinal surface and this rough surface presented less microleakage.…”

“…8 12 13 14 On the other hand, they cannot generate adequate roughness on tooth surfaces, which is essential for mechanical retention of cements like zinc-phosphate cement because of ineffective particle size. 15 16 17 18 19 …”

Minimal invasive microscopic tooth preparation in esthetic restoration: a specialist consensus

“…However, overt abutment tooth roughness leads to difficulties in final impression and causes irregular small bulges and high interferences that impact the insertion and fit of restoration. 92 With the converge of abutment tooth forms, the gaps caused by the rough surface of irregular bulges would enlarge, resulting in lowering of retention and occurrence of microleakage. 93 Therefore, polishing of the abutment tooth aims to smooth out the irregular interferences and increase the fitness with final restoration.…”