Effect of whitening toothpaste on CAD/CAM materials

Dental Tribune International

Fri. 10. April 2026

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ANKARA, Turkey: Given that the long-term performance of CAD/CAM restorative materials depends on both their intrinsic properties and response to staining and toothbrushing, the effects of coffee exposure and toothbrushing have been researched extensively. A recent laboratory study has investigated the effects of different toothpaste formulations when these challenges are applied sequentially. The findings offer clinically relevant insights for material selection.

To investigate the effects of whitening versus non-whitening toothpastes on the colour stability and surface roughness of CAD/CAM restorative materials under simulated oral conditions, researchers from Hacettepe University in Ankara employed thermocycling in a coffee solution, replicating repeated exposure to a staining agent and temperature fluctuations in the oral environment. This was followed by mechanical ageing through simulated toothbrushing with either a whitening toothpaste or a non-whitening toothpaste. The researchers evaluated colour stability and surface roughness after both stages.

The study investigated the glass-ceramics IPS e.max CAD and CEREC Tessera, as well as two resin-containing materials, SHOFU Block HC and VITA ENAMIC. While IPS e.max CAD has traditionally served as a benchmark for evaluating glass-ceramics, the inclusion of CEREC Tessera enabled the assessment of a new-generation glass-ceramic with regard to these challenges.

Material-dependent performance

The study found that the type of toothpaste did not significantly influence either colour stability or surface roughness, suggesting that whitening toothpastes may not necessarily cause greater surface degradation than conventional formulations. However, the response to staining and ageing was strongly material-dependent. The glass-ceramic materials demonstrated superior colour stability after coffee thermocycling and brushing. In contrast, SHOFU Block HC showed the greatest colour changes under the same conditions.

Surface roughness increased more significantly in the resin-containing materials, especially VITA ENAMIC, whereas the glass-ceramics largely maintained their surface integrity. The resin-containing materials exhibited increased roughness, micro-pits and irregular wear patterns. These effects suggest greater susceptibility of the resin matrix to abrasion. However, the authors noted that the differences were unlikely to be clinically relevant in terms of plaque accumulation.

From a clinical perspective, the results reinforce the reliability of glass-ceramics in maintaining aesthetic outcomes, particularly for patients with high exposure to chromogenic beverages such as coffee. In this context, Dental Tribune International has previously reported on a study suggested that 3D-printed glass-ceramics show promising mechanical properties and surface quality.

The researchers noted that, although resin-containing materials offer favourable mechanical properties and clinical versatility, they may require more frequent maintenance or repolishing to preserve their appearance over time. Their reduced colour stability in the study is consistent with previous findings indicating higher water absorption and greater susceptibility to staining.

The authors noted that further research is needed to evaluate the long-term effects of different dietary staining agents and toothbrushing protocols on a broader range of CAD/CAM materials, both in laboratory simulations and under clinical conditions.

The study, titled “Do CAD/CAM restorative materials respond differently to coffee thermocycling and simulated toothbrushing?”, was published online on 23 March 2026 in Clinical Oral Investigations.