Volume‐stable collagen matrix to treat gingival recession associated with non‐carious cervical lesions: Randomized clinical trial

BACKGROUND: Collagen matrices (CMs) have been used for the treatment of gingival recession defects. A new volume-stable collagen matrix (VCMX) was developed focused on enhancing tissue thickness due to a cross-linked collagen structure. Thus, the present randomized clinical trial aims to evaluate clinical and patient-centered parameters in the treatment of gingival recession (GR) RT1 associated with non-carious cervical lesions (NCCL) B+ partially restored using coronally advanced flap (CAF) alone or CAF and VCMX. METHODS: Forty patients diagnosed with GR RT1 plus NCCL B+ were treated with partial restorations (composite apical margin 1 mm beyond the estimated level cement-enamel junction), followed by CAF alone or with VCMX. Clinical, patient-related outcomes and esthetic measurements were assessed after 6 months. The recession reduction (RecRed) was the primary outcome. RESULTS: CAF and CAF+VCMX provided significant RecRed (1.87 vs. 1.78 mm; p = 0.76) and combined defect coverage (%CDC: 50.95 vs. 48.64%, p = 0.60) after 6 months. No difference was observed regarding the estimated root coverage (73.54 vs. 69.65%, p = 0.75). Greater gingival thickness (GT) gain was observed with VCMX (0.43 vs. 0.15 mm, p = 0.003). Both treatments decreased dentin hypersensitivity, achieved aesthetic satisfaction, and provided similar patient comfort. Keratinized tissue width is an important predictor for root coverage success while VCMX depends on it for greater RecRed (β = 1.775; p = 0.004). Combined defect (CD) height and depth can have both positive and negative impacts on coverage parameters. CONCLUSIONS: Both therapies provided significant CD coverage and RecRed, with no superiority of CAF+VCMX over CAF. However, VCMX led to a higher GT gain after 6 months (NCT05916716; IRB:46852621.0.0000.0077). PLAIN LANGUAGE SUMMARY: Combined defects (CDs), where gingival recession (GR) is associated with non-carious cervical lesions (NCCL), represent a clinical condition that clinicians frequently encounter. The lack of treatment worsens dentin hypersensitivity (DH) and esthetic perceptions. Some CDs require a surgical-restorative protocol. To date, partial restorative fillings combined with a coronally advanced flap (CAF), and connective tissue graft (CTG) surgical technique is considered the most predictable approach; however, the use of CTG has some drawbacks, including the risk of bleeding and patient discomfort. The use of collagen matrices (CMs) as an alternative to CTG has been assessed in the literature. This study aimed to evaluate a cross-linked collagen matrix (VCMX) in the treatment of GR/RT1 associated with NCCL/B+ partially restored. Despite similar recession reduction and combined defect coverage of up to 6 months, the VCMX promoted a greater increase in gingival thickness (GT) (0.43 mm). This is a crucial parameter for maintaining long-term clinical outcomes. Patient comfort and reduced analgesic intake in both groups display the clinical benefit against autogenous grafts. However, achieving satisfactory outcomes with VCMX requires adequate soft tissue features before surgery, such as a larger keratinized tissue width. While both treatments performed similarly, the higher GT gain was observed with VCMX.