The effect of tooth age on colour adjustment potential of resin composite restorations

A. Tanaka, M. Nakajima*, N. Seki, R. M. Foxton, J. Tagami

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)

Abstract

Objectives: The purpose of this study was to investigate the effect of tooth age on colour adjustment potential of resin composite restorations in human teeth. Methods: Twenty extracted human premolars with an A2 shade, extracted for orthodontic reasons from younger patients (20-28 yrs) (younger teeth) and periodontal reasons from older patients (45-69 yrs) (older teeth), were used in this study. Cylindrical shaped cavities (3.0 mm depth; 2.0 mm diameter) were prepared in the centre of the crowns on the buccal surface. One of four resin composites of A2 shade (Kalore, KA; Solare, SO; Clearfil Majesty, MJ; Beautifil II, BF) was placed in the cavity, and the colour was measured at four areas (0.4 mm × 0.4 mm) on the restored teeth (area 1; tooth area 1.0 mm away from the border of resin composite restoration: area 2; tooth border area 0.3 mm away from margin of resin composite restoration: area 3; resin composite border area 0.3 mm away from margin of resin composite restoration: area 4; resin composite area at the centre of resin composite restoration) using a spectrophotometer (Crystaleye). The colour of each area was determined according to the CIELAB colour scale. Colour differences (ΔE∗) between the areas of 1and 2,2 and 3,3 and 4 and 1and 4 were calculated, and also the ratio of ΔEarea 2-3to ΔEarea 1-4(ΔEarea 2-3/1-4), ΔEarea 3-4to ΔEarea 1-4ΔEarea 3-4/1-4) and ΔEarea 1-2to ΔEarea 1-4(ΔEarea 1-2/1-4) as a parameter of the colour shift in resin composite restoration, were determined. Moreover, the light transmission characteristics of the resin materials and dentine discs from the younger and older teeth were measured using a goniophotometer. The data were statistically analyzed using two-way ANOVA, and Dunnett's T3 and t-test for the post hoc test. Results: ΔEarea 2-3(colour difference between resin composite and tooth at the border) and ΔEarea 1-4(colour difference between resin composite and tooth) of the older teeth groups were significantly larger than those of younger teeth groups (p < 0.05). The ΔEarea 2-3/1-4(mis-match rate in colour shifting at the border) of the older teeth groups was larger than that of the younger teeth groups (p < 0.05). ΔEarea 3-4/1-4(colour shifting rate of resin composite side) was significantly larger in older teeth than younger teeth (p < 0.05), while ΔEarea 1-2/1-4(colour shifting rate of tooth side), was significantly smaller in older teeth than younger teeth (p < 0.05). In each tooth group, there were no significant differences in ΔEarea 2-3, ΔEarea 1-4, ΔEarea 2-3/1-4, ΔEarea 3-4/1-4and ΔEarea 1-2/1-4between the materials (p > 0.05). Analysis of the light transmission properties indicated that older dentine transmitted more light, while younger dentine exhibited greater light diffusion and transmitted less light. Conclusions: The colour shifting effects at the border of the resin composite restorations were influenced by the age of the tooth. This behaviour might be influenced by the light transmission characteristics of dentine in restored teeth. Clinical significance: The potential for colour adjustment of resin composite restorations may be less in older teeth than younger teeth.

Original languageEnglish
Pages (from-to)253-260
Number of pages8
JournalJournal of Dentistry
Volume43
Issue number2
Early online date19 Sept 2014
DOIs
Publication statusPublished - 1 Feb 2015

Keywords

  • Colour adjustment
  • Colour of resin composite
  • Colour shifting
  • Light transmission characteristics
  • Tooth age

Fingerprint

Dive into the research topics of 'The effect of tooth age on colour adjustment potential of resin composite restorations'. Together they form a unique fingerprint.

Cite this