In addition to creating esthetic and functional problems, gingival recessions may render teeth more susceptible to root caries, abrasion, and/or biocorrosion and may also cause cervical dentin hypersensitivity (CDH). Several root coverage procedures have therefore been developed to surgically treat these recession defects.
The Miller classification is a useful recession defect classification based on the height of the interproximal bone adjacent to the defect region and the relationship of the gingival margin to the mucogingival junction (MGJ). The Miller classification has four categories:
• Class I: Marginal tissue recession not extending to the MGJ and no loss of interdental bone or soft tissue
• Class II: Recession extending to or beyond the MGJ and no loss of interdental bone or soft tissue
• Class III: Recession extending to or beyond the MGJ with loss of interdental bone or soft tissue apical to the CEJ but coronal to the most apical level of the recession defect
• Class IV: Recession extending to or beyond the MGJ with loss of interdental bone or soft tissue apical to the CEJ and reaching the most apical level of the recession defect.
According to this classification, up to 100% root coverage can be anticipated in Class I and Class II defects, while less than 100% coverage is expected in Class III defects (but to the height of the adjacent interproximal bone peaks), and no root coverage can be anticipated in Class IV defects. However, the presence of NCCLs can make identification of the CEJ more difficult and can limit expectations for root coverage. Several surgical techniques have been used in the treatment of single and multiple recession defects. Regardless of the surgical approach, successful root coverage is defined as complete coverage with probing depths no deeper than 3 mm, no detected inflammation, and a tissue color and volume matching that of adjacent non treated regions.
Completing the restorative therapy before mucogingival surgery leads to various clinical advantages for both procedures: the restoration that can be easily performed and finished in an isolated field without interference of the soft tissues, and the root-coverage surgery is facilitated by the reconstruction of the clinical crown emergence profile that provides a stable, smooth, and convex substrate for the surgical flap. The main clinical concern is when to finish the composite restoration. Theoretically, the composite filling should be placed when gingival tissues are stable after the healing process of the mucogingival root coverage procedure. This position was described as the maximum root coverage level (MRC). This level is defined as a line (line of root coverage) that should coincide with the anatomic CEJ when it was not clinically detectable on the tooth with Miller Class I or II gingival recession or would be more apical than the anatomic CEJ when the ideal anatomic conditions to obtain complete root coverage were not fully represented (i.e., a Miller Class III gingival recession). A method to predetermine the MRC based on the calculation of the ideal height of the anatomic interdental papilla was demonstrated to be reliable in predicting the position of the soft tissue margin 3 months after root coverage surgery. The predetermination of the MRC can be used for the selection of the treatment approach of an NCCL associated with gingival recessions. The patient overall satisfaction as well were statistically correlated with color-match evaluations (VAS) and not with the amount of root coverage (in millimeters) achieved in each patient.
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