How To: Complete mid on lesions

Dentistry’s approach to diagnosis and management of dental caries has undergone a marked evolution over the last few decades.

Thanks to advancements in instrumentation, techniques and restorative materials, as well as scientific developments in cariology and diagnostic systems minimally invasive dentistry (MID) is now the standard of care in the modern restorative practice.

Defined as a conservative approach to saving tooth structure, MID requires a change in traditional cavity preparation design. While traditional preparations follow a lesion-centered method as described by G.V. Black’s “extension for prevention” fundamentals of dentistry,1, 2 MID designs require a much more conservative approach. Based on advances in science that have furthered our understanding of the caries process and remineralization, this method relies on dental science to detect, diagnose, intercept and treat dental caries at an early stage, thus impeding disease progress.2

To approach dental treatment from the proper perspective, it’s imperative to understand that caries is a bacterial disease that must be eliminated. Modern materials enable us to remineralize and heal demineralized tooth surfaces, thereby reducing future incidence of caries and minimizing tooth-structure removal during preparation.3 To successfully practice MID, carious lesions must be detected as early as possible so caries progress can be halted with preventive remineralization therapy.1 Due to the restorative cycle of placement and replacement, which necessitates progressive loss of tooth structure, the goal for any restoration is to maintain as much natural tooth structure as possible. Likewise, durable, long-lasting restorations must be appropriately placed to further diminish the cycle.1,2

As the disease process begins, bacterial pathogens cause reversible demineralization of hard tooth structure. At this stage of the disease, a lesion is termed “subclinical” because it isn’t detectable via visual, tactile or radiographic means. Simply put, the tooth structure in question looks and feels like a normal healthy tooth.4 Presenting a unique diagnostic challenge, such noncavitated carious lesions may indicate high caries activity and caries risk.1 It’s well established that mineral loss associated with caries can be arrested and even reversed at an early stage, before cavitation occurs;2 however, if the needed remineralization isn’t initiated, the disease will progress to an irreversible stage leading to tissue morbidity. It’s therefore incumbent upon dentists to treat caries in the subclinical (i.e., noncavitated) stage.4

MID instrumentation
In addition to proper restorative materials, the appropriate instruments must be used to operate within minimally invasive restorative principles. KOMET USA’s CeraBur® system is an advanced bur system created to preserve the maximum amount of tooth structure while addressing the removal of caries only. CeraBur® Kit 4547 features a range of K1SM ceramic instruments that are highly efficient for minimally invasive excavation on soft, carious dentin with minimized reduction of sound tooth structure. Offering superior tactile capacity, the burs essentially tell the operator when it’s safe to stop drilling. The burs are made of high-quality ceramic, and they effectively reduce the need for explorers and spoons in evaluating decay removal. Because of their ceramic composition, the long-lasting, smooth-running burs resist corrosion and are unharmed by disinfection and cleaning processes.

Another indispensable component of the dental armamentarium is the KOMET family of Micropreparation instruments. Engineered with smaller-than-standard working parts and thin necks, these diamonds are specially suitable for minimally invasive preparations in microdentistry. Together, the CeraBur® system and the Micropreparation diamonds create the ideal toolbox for minimally invasive tooth preparation.

The following case demonstrates  minimally invasive restoration of a noncavitated carious lesion, with a focus on vital preparation steps.  
MID on a noncavitated carious lesion

Recognition and treatment of noncavitated carious lesions are vital to the MID process. Treatment at this early stage is aimed at preserving integrity of the tooth and averting additional, more aggressive therapy later.  

A 26-year-old female patient presented for a routine examination, during which a noncavitated carious lesion was discovered on the maxillary left first molar, tooth No. 14 (Fig. 1). After discussing a treatment plan designed to arrest caries progress, the patient elected the recommendation to undergo treatment for noncavitated lesion with a minimally invasive tooth restoration using a flowable composite resin.   

Following local anesthesia, initial cavity access was achieved with the KOMET 889M.FG.007 tapered diamond Micropreparation bur (Fig. 2).

With the same bur, the cavity preparation was then widened for visual and instrument access (Fig. 3).

Once access was achieved, a CeraBur® K1SM round ceramic bur was used at 1,500 rpm for slow-speed excavation of caries (Fig. 4). With exceptionally smooth operation and optimal cutting efficiency, the bur achieved complete caries removal. With its superior tactile feel, the CeraBur essentially signaled when it was safe to stop drilling. The maximum amount of tooth structure was preserved with the removal of caries only. The completed preparation shows the integrity of the tooth has been maintained thanks to the minimally invasive technique made possible by using the appropriate instruments (Fig. 5).

The cavity preparation was restored using the dual-etch technique; a resin-reinforced, glass-ionomer base for remineralization of affected dentin; bonding agent; and a microhybrid composite resin.

Following composite placement, the restoration was given a final polish with the KOMET 9686.RA.040 silicone brush (Fig. 6). The restoration is completed (Fig. 7).

Conclusion
Although small to the naked eye, this MID restoration represents decades of scientific research and engineering. After receiving a very small composite filling, this patient walked out of the office caries-free, armed with the knowledge she needed to maintain good dental health for a lifetime.
By conserving dentition and supporting structures, minimally invasive dentistry is gratifying to both doctor and patient.5 The current generation of composite restorative materials facilitates minimal intervention without sacrificing strength or beauty.3 To successfully perform MID, however, it is imperative to have the appropriate tools at hand. KOMET USA’s CeraBur® instruments are ideal for a multitude of techniques, and they are especially suited to MID procedures.  

References
1. Strassler, HE. Minimally invasive dentistry: today’s restorative materials meet the challenges. Kerr University Online Learning Center, dentalaegis.com.
2. Murdoch-Kinch CA, Mclean ME. Minimally invasive dentistry. J Am Dent Assoc.. 2003;134(1):87-95.
3. Okuda WH. Minimally invasive dentistry: a natural evolution in cosmetic restorative dentistry. Inside Dentistry. January 2011;7(1):54-62.
4. Conners D., Curtis A., Cziok A., Donnelly R., Duchsherer C., Dunlavey R., Elmelakh M., Elmaijri A., Fiedler J., Fordahl B., Zidan O. Dental caries: the non-cavitated carious lesion. Course lecture, University of Minnesota. 2004.
5. Christensen G. The advantages of minimally invasive dentistry. JADA. 2005;136:1563-1565.

About the author
Dr. Ian Shuman maintains a full-time general, reconstructive, and esthetic dental practice in Pasadena, Md. Dr. Shuman has lectured and published on advanced, minimally invasive