Influence of illuminants and different observers on the perception of surface gloss of resin composite

Abstract

<pre><strong>Objective:</strong> To evaluate the visual perception of surface gloss of resin composite under different illuminants by different observers. <strong>Material and methods:</strong> twelve cylindrical specimens (6mm x 1mm) were fabricated using a nanofilled resin composite (Z350, A2E shade) in order to compare different observers and to determine the limit of perceptibility of surface gloss. Bovine tooth specimen with similar dimensions was obtained for the comparison of different illuminants. Polishing of resin specimens was performed resulting in 6 groups, presenting surface gloss values at 10, 25, 40, 55, 70, and 85 GU (gloss units), measured by glossmeter (NOVOCURVE). Fifteen individuals were selected: 5 lay-person, 5 undergraduate students, and 5 dental professionals. Participants observed the specimens in a light booth (Gti lightbox) under three different illuminants, and rated the possible combinations between resin specimens or with the bovine enamel specimen (85GU). Data obtained were analyzed by PROBIT non-linear regression analysis (α=0.05). <strong>Results:</strong> Differences were observed among types of illuminants (p=0.042) and ΔGU (p=0.004), with no interaction between factors (p=0.139). The fluorescent light presented lower surface gloss perceptibility values in relation to incandescent light. There was no influence by type of observers (p =0.598). The surface gloss perception limit was 17.6 GU under the presented tested conditions. <strong>Conclusion:</strong> the illuminant type influenced perception of gloss, with lower percentage of perceptibility for fluorescent light, while such perceptibility was not influence by different observers. </pre><p class="PadroAA"><strong>Keywords</strong><strong></strong></p><p class="PadroAA"> Illuminants; Observer variation; Composite resins; Surface gloss.</p>

Gloss retention of direct composites and corresponding CAD/CAM composite blocks

“…When judging on the clinical relevance of gloss variation in the three experiments, not only statistical differences have to be taken into account but also their clinical implications. According to Tessarin et al (2018) ΔGU of 17.6 units is the limit of perceptibility of gloss variation, which is defined as the probability of at least 50% of observers to detect a gloss difference. Based on this criterium, alcohol did not affect human gloss perception with all materials tested, while Elmex gelée perceptibly affected all tested materials with the only exception of Cerasmart 270, and the brushing test caused clinically perceptible changes in all the tested materials.…”

Qual a importância do acabamento e polimento em restaurações diretas de resinas compostas nos dentes anteriores?

“…Sendo assim, é imprescindível que o cirurgião-dentista siga um protocolo de acabamento e polimento apropriado, com técnicas e materiais adequados. Estes procedimentos favorecem a manutenção da saúde dos tecidos, além da integridade do procedimento restaurador a curto e longo prazo (Tessarin, et al, 2018).…”