During my presentations I am often asked why clinical research into bonding systems is conducted using class V situations.

The non-carious class V lesion is most suitable for this type of research for a number of reasons. Unquestionably, the main reason is the fact that such lesions present little or no macro retention. It must be remembered that if a cavity presents macro retention, loss of adhesive strength in the bonding interface will not automatically lead to loss of retention.

Other major reasons (in no particular order) are that such lesions occur relatively often, but also that in general they are situated in an easily accessible area and do not demand complex restoration technology. The configuration factor is low (ratio between free and bonded areas) and does not therefore cause much shrinkage stress. In addition, both enamel and dentine are involved in the restoration, although in some studies efforts are made to limit bonding to enamel (for example, in Van Dijken et al., Clinical long-term retention of etch-and-rinse and self-etch adhesive systems in non-carious cervical lesions. A 13 year evaluation. Dent Mat 2007).

The restoration is then re-assessed periodically. Obviously, loss of retention is considered, and sometimes restorations are also assessed on marginal integrity, marginal discolouring and aesthetics.

Whenever a restoration goes wrong, this is noted as a failure. The survival/lifetime of restorations is expressed in an Annual Failure Rate; for example, an AFR of 4.6 means that, on an annual basis, 4.6% of the restorations failed in the course of the study.

Phosphoric acid, sometimes also called orthophosphoric acid, is a substance that is used frequently in the practice of dentistry, mostly in concentrations between 30 and 40%. It is a proven substance for the etching of enamel (Buonocore 1955). It also entails hazards, because contact with the eyes and skin may cause severe irritation, blistering and burns.

The substance should only be applied where its use is intended, and proper control is of the essence. The use of a coloured gel is therefore recommended, preferably of a thixotropic type. The application of a cofferdam is also definitely recommended, and the patient should wear protective glasses ( the practitioners should obviously also wear protective glasses). When removing the etching gel, the main volume should first be sucked away using a saliva ejector without a cap. The area should then be rinsed clean with a spray mist suction device under continued suction.

If the etching gel should unintentionally get onto the skin or, even worse, into the eyes, the affected area should be rinsed with plenty of water until the patient no longer feels any pain in the affected area. In such a case, it is recommended that medical assistance be sought.

This article is based on a publication in the British Dental Journal Vol 217 No.2 Jul 25 2014
Link to the publication. 

I would like to refer to a recently conducted study by Garcia et al. to reply to this question, which derives from practice. The study examines the effect of three desensitisers on the bonding strength to dentine of a composite cement.

The study concluded that the effect is dependent on the material. Gluma Desensitizer (Heraeus Kulzer) and Super Seal (Phoenix Dental) decreased the bonding strength, whereas TeethmateTM Desensitizer (Kuraray Noritake) improved the bonding strength. The researchers obviously consider it necessary to conduct further research into the workings of TeethmateTM Desensitizer, a cement that contains calcium phosphate.

Clinical significance:

TeethmateTM Desensitizer, a material containing calcium phosphate, may serve as a useful new generation of desensitisers for use prior to the cementing of indirect restorations.

Click here for the research abstract.

Clinically proven

13 years of clinical evaluation show exceptional results for SE Bond.

The clinical effect of CSE in non-carious class V lesions remained excellent after 13 years. Selective etching on the enamel margins had only a limited positive effect on marginal integrity and absence of marginal colouring.

This is the conclusion of the study that was published last year:

A thirteen-year randomised, controlled clinical trial of a two-step self-etch adhesive in non-carious cervical lesions, by M. Peumans and colleagues from KU Leuven BIOMAT. Dental Materials 31 (2015) 308-314

This publication comprises the evaluation of the study after 13 years; the evaluations after 3, 5 and 8 years have already been published. NCCL’s (non-carious cervical lesions) are the most suitable treatments for the clinical testing of bond effectiveness. Only a limited number of studies with long-term results are available, and 13 years is the longest evaluation period to date.

So far, CSE is the only bonding to perform so well over such a long period of time.

Loss of retention is the most objective parameter in establishing the effectiveness of bonding in such a clinical test. The 13 year retention rate of CSE was high in this clinical test: no less than 96%!

In the course of this study, half the cavities were treated with CSE without the etching of the enamel margins with phosphoric acid; the other half were treated with selective etching of the enamel. Etching or non-etching of the enamel margins had no effect on the retention rate.