Dentists today are confronted with patients who have high aesthetic demands at a low cost. The move toward minimally invasive dentistry is proving beneficial for these needs, protecting the pulp and increasing the longevity of teeth. However, many dentists find the huge number of products and the complex procedures involved are a lot of work — not just for them, but for their staff, too. To support patients’ needs, dental professionals need products that work fast and offer high bond strength, good marginal seal and tolerance against moisture and contamination.
Minimally invasive dentistry helps save as much tooth structure as possible to increase the longevity of the tooth. The reason being: maintaining the vitality of the pulp is more important than complete caries removal. Thus, on the cavity floor, only soft caries-infected tissue should be removed, with firm carries-affected tissue as the endpoint. In deep lesions, even spots with soft infected tissue can be left behind to avoid opening the pulp.
Preparation guidelines for minimally invasive dentistry have changed considerably in recent years. It is recognized that long-term survival of restorations depends on a stable bond to enamel and dentin. With minimally invasive dentistry caries, affected dentin is preserved during excavation. 3M™ Scotchbond™ Universal Plus adhesive bonds to firm caries-affected dentin with similar strength as to sound dentin, providing greater confidence in minimally invasive preparations.
Research has shown that it is not possible to remove all bacteria from a lesion by preparation. For this reason, it is important to seal in remaining bacteria to block it from nutrients, which will help stop caries progression. Scotchbond Universal Plus provides two lines of defense against caries progression. It offers an excellent marginal seal, as shown in a study by Dr. Blunck from the Charite University in Berlin, and it seals carries-affected dentin by forming a well-defined, void-free hybrid layer.
The addition of adhesive materials to the buccal enamel can make the tooth thicker, adding strength to the dental structure. There is also the possibility of hiding margins and defects, improving the shape and offering a very aesthetic outcome.
One challenge with preparing for minimally invasive dentistry is misleading radiographs due to optical illusions, super-imposition artifacts from planes with different radiopacity, cervical burnout artifacts and computer processing artifacts. In a survey of 309 general dentists across the U.S. and Europe, 51% of respondents said they need to interpret at least one questionable X-ray per day. This makes it difficult to distinguish between secondary caries, voids, gaps or pooling of non-radiopaque adhesive, leaving the potential for misdiagnosis of secondary caries and over-treatment.
Dr. Burgess of the University of Alabama shared these concerns, noting that “radiolucency from pooling underneath the restoration doubles the risk of restoration replacement,” while Dr. Putignano from Style Italiano reported challenges with questionable radiolucency under fillings, sharing that these hard-to-interpret X-rays “happen every day,” leading to a lack of clarity in bitewing radiographs.
According to ISO standards, the radiopacity of human dentin is measured in percentage of aluminum. Scotchbond Universal Plus and dentin have a radiopacity of 100% aluminum, but the Scotchbond product has a significantly higher radiopacity than other adhesives tested, helping to avoid radiolucencies and minimize misdiagnosis of secondary caries compared to other universal adhesives.
One other recent shift in dental practices is a move away from bisphenol A and BPA due to safety concerns. Scotchbond Universal Plus replaces the BisGMA resin in the original Scotchbond Universal. This enables entirely BPA-free workflows for direct and indirect restorations. For indirect restorations, it can be combined with the new 3M™ RelyX™ Universal Resin Cement. For direct restorations, it can be combined with 3M™ Filtek™ Universal Restorative, or 3M™ Filtek™ One Bulk Fill Restorative.
Scotchbond Universal Plus affords an increased bond strength to glass ceramic at the level of gold standard separate from sealant primers. With its integrated dual cue accelerator, Scotchbond Universal Plus does not need a separate dual cue activator vial anymore. This makes it the one and only adhesive for all cases. The product remains homogenously mixed with other components of the formulation, unlike radiopaque filler particles, which can settle from formation. Therefore, no shaking of the bottle in needed.
If you're already using Scotchbond Universal, there are no changes to the workflow. Application is easy to apply, with agitation to the prepared optionally etched tooth for 20 seconds, then air drying with a gentle stream of air for at least five seconds until the adhesive no longer moves. This indicates complete removal of the ethanol and water solvents. The adhesive should look glossy after air drying. If it looks dull, the adhesive layer is not sufficient and it should be reapplied until a glossy appearance is obtained.
A clinical case performed by Dr. Alberto Ferrariroa in Madrid illustrates the workflow. An X-ray showed hidden caries at the distal side of the upper first premolar. After isolation with a rubber dam, the tooth was prepared. A selective enamel etched technique was used. Phosphoric acid gel was applied for 15 seconds to the enamel, and then rinsed and lightly air dried. Scotchbond Universal Plus was applied to the enamel and dentin using a rubbing motion for 20 seconds, air dried with a gentle stream of air for at least five seconds until the adhesive no longer moved, and the glossy adhesive layer was obtained.
The adhesive layer was light cured for 10 seconds. After adaptation of the matrix system, the restoration was placed using 3M Filtek Universal Restorative in shade A2. The restoration was polished with a 3M™ Sof-Lex™ diamond polishing system. In the first step, the pre-polishing spiral was applied, followed by the diamond polishing spiral in the second step. The last image shows the final restoration.
The fully aligned system of RelyX Universal Resin Cement, used together with Scotchbond Universal Plus adhesive, provides excellent bond strength to enamel and dentin with fewer components and less working steps. This means simplification of workflows with just two components. In a study by the Dental Advisor, RelyX Universal Resin Cement was shown to be strong on all substrates in the self-adhesive mode, as well as in the adhesive mode together with Scotchbond Universal Plus. RelyX Universal Resin Cement had the highest measured self-adhesive bond strength to dentin and zirconia compared to other self-adhesive resin cements.
As less invasive dentistry becomes the norm, there is greater reliance on adhesives for protecting against dental disease. Products with a higher safety tolerance and fewer procedure steps are in high demand. Adhesives such as Scotchbond Universal Plus offer high-performance, safer materials and greater control and predictability.
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