Sulcus-Seated Modified Tofflemire Matrix Enables the Crown Lengthening-Free Restoration of a Deep Cervical Lesion on a Maxillary Canine: A Case Report

Deep cervical lesions with subgingival margins are traditionally managed by crown lengthening; however, this surgery can compromise aesthetics and the periodontium. This report describes a minimally invasive technique that combines a custom-trimmed Tofflemire matrix with modern adhesive and thermally enhanced composite placement to relocate the margin coronally and restore the defect without surgery. A 63-year-old healthy woman presented with a non-carious cervical lesion on the maxillary left canine (FDI #23). After infiltration with 1.8 mL of 3% mepivacaine (without epinephrine), a stainless-steel Tofflemire band was shortened to ~2 mm height and seated interproximally until gingival blanching confirmed sulcular sealing. The enamel-dentin interface was etched with 35% phosphoric acid, rinsed, and primed with two coats of a fifth-generation adhesive (Prime & Bond NT (Dentsply Sirona, Charlotte, North Carolina, United States)) followed by light-curing. A thin layer of flowable composite "wetted" the surface, and then a preheated nanohybrid composite (Filtek Supreme Ultra, Body A2, 68°C (3M, Saint Paul, Minnesota, United States)) was injection-molded into the matrix and incrementally light-cured from multiple angles. After matrix removal, finishing and polishing were performed with fine diamond burs and multi-step rubber polishers. The modified matrix provided stable isolation, enabling precise adhesive placement and warmed composite buildup in a single visit. Clinical inspection revealed a flush cervical margin, healthy gingiva, and an anatomically accurate emergence profile. The patient reported no postoperative discomfort, and no surgical intervention was required. A simple chairside modification of the Tofflemire matrix can facilitate predictable sulcular isolation and margin elevation in subgingival cervical lesions, offering a conservative, single-visit alternative to surgery. Further clinical studies with larger samples and long-term follow-up are needed to validate this approach.