Non-carious class V lesions are characterized by a loss of tooth structure in the cervical region of the teeth. Restorative treatment is indicated when there’s an aesthetic, functional or biological compromise and in cases of hypersensitivity unresponsive to a non-invasive therapy. Before making any restorative procedure, however, it is necessary to diagnose and control the etiologic factors of the lesion which can be corrosion, abrasion, abfraction or any association of these factors. If it is chosen to restore, prophylaxis and shade selection are initially carried out.

With the chromatic information properly recorded, complete isolation of the operative field is performed preferably with the aid of retraction clamps to ensure that the gingival margin of the cavity is exposed properly.
In some situations, retraction clamps need to be modified to fit the needs for the gingival retraction of the case. After being taken into position with the clamp holder, the #212 clamp should be stabilized with a low fusion compound that does not move during restoration. To this purpose, small cones of the compound are plasticized in the flame of a lamp and positioned on the wings of the clamp and the interdental spaces through digital pressure.

With the margins of the cavity completely exposed, due to the action of the retractor clamp, it is time to start the restorative procedures.
One of the great advantages of using composites to restore class V noncarious lesions is the nature of the adhesive material which allows the clinicians to eliminate the preparation of macro-mechanical retentions mandatory for non-adhesive restorations. The restorative procedure is restricted primarily to the replacement of the lost structure without any additional previous grinding. For the procedure to be successful, however, it is important to know and respect the particularities of the dental substrates present in the cavity. Although in some cases the lesion margins are completely located within enamel the most common is that the margin is placed in cervical dentin. For this reason, it is important to take into consideration the structural differences between the tissues to allow for the simultaneous establishment of a good bonding to enamel and dentin.
The pictures below illustrate the steps involved in using a two-step bonding system, with etching.

👉 For more details about bonding techniques click the link
The application of acid is initiated by enamel and extended to dentin where it remains for 15 seconds and then washed for equal time. After washing, dentin is kept moist and at least two layers of the adhesive system are interspersed by mild air jets that have the function to volatilize the solvent of the adhesive system.
At this point, it is important to remove excess adhesive which tends to remain pooled along the margins and on the claw of the clamp. Then the adhesive is light-cured and the composite is inserted. Because of the close relationship between the class V restorations and the periodontium, it is essential to choose composites with good polishing features. The need to use composite with optical characteristics similar to those of dentin occurs only in the deepest cervical lesions. In more superficial lesions it is generally sufficient to use only composite for enamel.
With the aim of reducing the stresses generated by the polymerization shrinkage, small increments of the composite should be used, adapted and inserted sequentially, first to the cervical margin and then on the occlusal margins of the cavity.

This technique of insertion allows for control over the deleterious effects of polymerization shrinkage and facilitates the stratification of highly aesthetic restorations thanks to the overlapping of the masses of composite with different thicknesses and degrees of translucency.

In the figures presented, you can see the insertion sequence of the masses of the composite. Initially, an increment of composite slightly more saturated is applied and adapted against the cervical margin of the cavity with the aid of spatulas and brushes. Before curing, the contour is checked to make sure there is no rough excess and that the volume filled is compatible with the dimensions of the cavity. Subsequently, light curing is performed. The second increment is inserted in order to fill the space between the occlusal margin and the composite resin already polymerized, but carefully so that space remains for a final composite layer. After light curing the final increment is inserted in order to restore the total volume of the restoration. Again the use of brushes is recommended to minimize the retention of excesses and provide the composite a smooth and uniform surface. At this point, it is interesting to observe the profile of the restoration and check if it follows the adjacent teeth. After curing, the final restoration is nearly complete missing only the finishing and polishing.

The finishing is limited to the removal of any excess adhesive and resin on the margins of the restoration. Number 12 scalpel blades and flexible abrasive discs are very suitable for this step. These steps are carried out whenever possible before removal of the rubber dam and the clamp due to the need for the removal of soft tissue and to have excellent access to the gingival margin. The finish of this margin without the presence of the clamp is generally hampered by the presence of the gingival tissue and the occurrence of located bleeding.

The final polishing is carried out with polishing pastes applied with Robinson brushes or felt discs. Note that the restoration restores the shape and aesthetics of the natural tooth.