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MPa – a new single bottle adhesive from Clinician’s Choice

Which generation is best?The question as to ‘Which generation of bonding adhesive is best?’ continues to create much debate among clinicians, with most dental professionals expressing their own preferences, and with each having their own favourite product.

Each generation of these materials probably has its own advantages, but whatever the pros and cons there is a universal criteria that must be met if a successful restoration is to be achieved, and the factors influencing success or failure can be defined as follows:1. Successful etching capability.2. The prevention of post-operative sensitivity.3. Ease of use.4. Consistent application.5. Prevention of microleakage6. High bond strength.

MPa – a single bottle resinThe Clinician’s Choice company of Canada has introduced a one-bottle adhesive that can be defined as ‘etch and rinse’, and it

utilises scientifically advanced and clinically proven chemistry. The resultant product, called MPa (Maximum Performance adhesive), addresses each of the above points.

Previous 4th and 5th generation systems have required the application of three, four or even five coats of primer (this is why low-bond strengths or sensitivity can result) and a nano-filled 7.5% second resin.

MPa is a single bottle system and only requires a single coat application. MPa has natural resins and its slightly higher film thickness ensures that only a single coat is needed to address virtually all bonding situations. It succeeds in sealing the dentine tubules resulting in a sensitivity-free and totally sealed restoration.

Total etch vs self-etchMost operators agree that the total etching will create higher adhesive strength to enamel, and in testing with total etch techniques it was found MPa did achieve this, and that this also helped prevent microleakage in the long term.

Clinically, although somewhat more convenient and quicker to use, some self-etching systems can result in a poor enamel etch/bond, and stained margins have been observed with premature microleakage.

It is therefore recommended that a properly etched, enamel or dentine surface be created by the use of a 37% phosphoric acid etch material. This will ensure that a more effective result will be achieved. A properly etched enamel or dentine surface will allow for the proper penetration of the MPa resin and will consistently result in a strong bond.

As if to reinforce the effectiveness of MPa, Walter et al, states that ‘the dentine bond strength of MPa direct was higher than that of four other systems, with the difference being statistically significant for three of these. In addition, MPa Direct was very effective for bonding self-cure composite resins when the adhesives oxygen inhibited layer was removed with alcohol.’1

Use of G5 desensitiserThe Clinician’s Choice company also produces G5, an ‘all purpose’ desensitising agent that can be used after acid etching. This material has been proven over the long term, and it effectively coagulates the plasma proteins within the dentinal tubules, thus helping to create a dry seal. When used in conjunction with MPa, G5 will shut down the intra-tubular liquid flow, thereby helping prevent post-operative discomfort. G5 also helps to stabilise the bond long term.

MPa and G5 can be used in combination, as shown in Figures 1-6.

Reference1. Walter, R, Swift, E.J, Ritter, A.V. et al. ‘Dentine Bonding of a new etch-and-bond adhesive using self and light-cured composites’, American Journal of Dentistry, 2009.

A new aid in bonding is described here by Tony Beale

MPa Direct and G5 Desensitiser are both available from Optident Ltd, International Development Centre, Valley Drive, Ilkley, LS29 8AL. Call 01943 605050, email sales@optident.co.uk or visit www.optident.co.uk.

Figure 1: An amalgam restoration-prepared tooth

Figure 2: Etch for 15 seconds Figure 3: Rinse thoroughly for five seconds, lightly air dry and apply G5 (optional)

Figure 4: Apply MPa for 10 seconds

Figure 5: Air thin and evaporate MPa solvent, 10 seconds

Figure 6: Light cure for 10 seconds Figure 7: Clinician’s Choice MPa single bottle adhesive