A conversation with NYSDA President David J. Miller, D.D.S. 18 Preparing and Restoring Composite Resin Restorations The Advantage of High Magnification Loupes or the Dental Surgical Operating Microscope

Use of magnification, such as 6x to 8x binocular surgical loupes or the surgical operating microscope, combined with co-axial illumination, may facilitate the creation of stable composite resin restorations that are less likely to develop caries, cracks or margin stains over years of service. Microscopes facilitate observation of clinically relevant microscopic visual details, such as microscopic amounts of demineralization or caries at preparation margins; microscopic areas of soft, decayed tooth structure; microscopic amounts of moisture contamination of the preparation during bonding; or microscopic marginal gaps in the composite. Preventing microscope-level errors in composite fabrication can result in a composite restoration that, at initial placement, appears perfect when viewed under 6x to 8x magnification and which also is free of secondary caries, marginal staining or cracks at multi-year follow-up visits. Use of microscope-level magnification, combined with co-axial illumination (MLMCI), may improve a dentist’s ability to prepare, bond, restore and adjust composite restorations,1-3 compared to the use of unaided vision and non-co-axial, shadowforming overhead lighting. A co-axial light axis is coincident with the visual axis of the dentist’s eyes, resulting in shadowfree illumination.4-6 Diagnosis and Removal of Dental Caries MLMCI facilitates observation of the colors and textures of carious material and verification that a slow-speed round bur has removed all soft, carious tooth material from the margins and base of the preparation.7-14 Microscopically precise tactile sensitivity enables associating the feel of an explorer probing a soft carious point with the point on the preparation surface where the caries exists. MLMCI also makes possible detection of sub-gingival plaque, food particles or calculus that is contiguous with a preparation margin. And it aids in distinguishing this material from caries, stained but non-carious tooth structure or healthy marginal tooth structure. MLMCI facilitates detection of microscopic caries at the contact points of inter-proximal surfaces and caries at the superior aspect of Class III preparations, as well as caries hidden underneath cusp tips or undercut areas of a posterior preparaPreparing and Restoring Composite Resin Restorations The Advantage of High Magnification Loupes or the Dental Surgical Operating Microscope John Mamoun, D.M.D. restorative dentistry