Use of magnification in dental technology.

UNLABELLED: Binocular stereoscopic microscopes have been used in dental technology for decades to improve visual acuity during the fabrication process. Technicians endeavor to produce a restoration that has marginal discrepancies of < 50 microm and to polish the surface of the restorative material so that there is minimal bacterial accumulation. There are six key areas in which the use of magnification is critical to fabricating high-quality restorations: inspection of the impression; trimming and marking of the margin on the die; waxing of the margin; fitting of the initial casting, pressing, or milled unit; final fitting of the restoration; and polishing of the restoration. This article explains some of the specific areas in which dental technicians rely on magnification to increase the probability of a long-term biologically acceptable restoration. CLINICAL SIGNIFICANCE: Precision in the dental laboratory during fabrication of indirect restorations is crucial to long-term clinical success. An intimate but passive fit to the restoration ensures complete seating at the time of cementation with excellent marginal integrity and subsequent minimal occlusal adjustments. A restorative surface that is smooth and well polished in the gingival third results in minimal bacterial accumulation and a healthy periodontium.