Restoration of worn teeth with composite resin additions
This patient presented wanting an aesthetic improvement, she was seeking a “natural look”.
She was aware of the localized wear on her maxillary anterior teeth, and the wear, although less so, of her mandibular anterior teeth. She was presented with a number of treatment solutions, these included ceramic veneers or composite resin additions, with or with out the inclusion of orthodontic treatment. She chose the later, with an understanding that the treatment may have long term limitations.
Her treatment plan involved orthodontics to align her moderately crowded anterior dentition, improve the maxillary arch form, align gingival levels and create space for restorative material, to be placed on the maxillary anterior teeth.
Once orthodontic treatment was completed another aesthetic analysis was carried out utilizing conventional aesthetic guidelines and the Digital Smile Design protocol, described by Christian Coachman, this helped provide clear direction so that an accurate diagnostic wax-up could be fabricated.
The midline and incisal edge position were determined first, followed by the incisal plane.
Pleasant tooth proportions were considered when finalizing the aesthetic analysis.
The diagnostic wax-up was a direct result of the aesthetic analysis.
The accuracy of diagnostic wax up was then verified by carrying out a direct mock-up. Because so much of the treatment outcome is dependent on the wax-up, the author routinely arranges a separate short appointment for the purpose of verifying the wax-up prior to treatment. Corrections were made prior to the restorative appointment.
The wax up was used to fabricate a lab putty key which was used as a matrix in the fabrication of the restorations.
The diagnostic wax-up will define the palatal surface and the incisal edge of the definitive resin restorations and to that end must be accurate. It is important that the palatal inter-proximal regions are well defined, this will prevent excess resin finding its way to the proximal regions.
In the same way, the lab putty key will also need to be accurate, this can be achieved either by ensuring it cures under pressure (in a laboratory pressure pot) or by relining the key with light body silicone impression material.
The key was trimmed so that it would not interfere with the rubber dam isolation, so it extended distally to the 2nd premolars and material was removed form the palate.
The key was the sectioned through the incisal edge.
Shade selection was carried out as a first step. This was done using shade tabs (Inspiro composite system). Dentine shades were selected based on the Chroma in the cervical and middle third of the teeth (Bi2), slightly warmer for the canines(Bi3). A brighter enamel shade (SB) was selected with a view to lifting the overall value of the teeth to be restored.
Firstly, the teeth were cleaned, all old restorative material was removed, proximal surfaces were cleaned with abrasive strips, gentle bevels were created on the incisal edges to soften the optical transition from tooth structure to restorative material. Finally all teeth to be restored were thoroughly cleaned with pumice and cup. Isolation was maintained with rubber dam and floss ligatures.
The silicone key was tried in and then the teeth were etched, primed and uncured bond was placed on all etched tooth surfaces (Scotch bond 2, 3M). The bond was thinned uniformly with air and not cured.
Enamel shaded material was placed in the key in the usual way. Important points are; to keep the enamel layer thin so that ultimately it does not interfere with positioning of the dentine mass; ensure there is little or no composite in the proximal regions.
The key is positioned on the teeth and time is taken to further thin the enamel shaded material and ensure there is little material in the proximal areas. Some dentine composite can be pushed in between the enamel shaded material and tooth on the palatal while the material is still un-set to ensure there is no porosity in this region. The composite can now be completely cured completely and the putty key removed.
Placement of the dentine mass is carried out with a view to the desired final lookof the teeth in mind. In this case a three mamelon arrangement was chosen for the central incisors and two mamelon arrangement was chosen for the lateral incisors. The mamelons were carried to but not beyond the incisal edge. Accurate placement of the dentine mass is critical to the final appearance of each individual tooth… this in turn is directly related to the accuracy of the wax-up and key and positioning of the enamel palato-incisal wall.
It is my preference to add the dentine mass prior to the proximal wall build -up, so that nothing is interfering with the placement and positioning of the dentine mass.
Some effect materials were added at this point. In the Inspiro range there are an number effect materials conveniently packaged as flowable materials. A white effect material (ice) with moderate opacity (similar to dentine) was selected to highlight the incisal halo. A warm golden effect material (chroma) was selected to increase the level of chroma in the middle mamelon (central incisors and canines) and the mesial mamelons of the lateral incisors. Finally small amounts of blue effect material (azure) were added to the proximal and incisal regions.
Once cured each build up will have sufficient strength so that the contacts can be separated with a separating strip and possibly some proximal abrasion with strips to ensure accurate adaption of proximal matrices (mylar strips).
In completing the final enamel layer, the proximal surfaces were completed first. This was done one by one, commencing with the midline and moving laterally.
The midline addition is most important and will typically need to be trimmed with a sof-lex disc to ensure the midline is positioned accurately.
Once the the proximal additions are complete the labial enamel is placed, positioning of this mass is the least critical and this can be carried out relatively rapidly, always being careful not to incorporate porosity.
Light curing of the composite restorations is completed at this stage and the restorations are refined with flame shaped diamonds and sof-lex finishing disks. At this point the restorations are not completely finished and polished. This is carried out at a later appointment
The rubber dam is removed.
Taking photographs of the restorations at the end of the build-up appointment provide the operator with an opportunity to objectively evaluate the restorations and contemplate what alterations may improve the final result.
The advantages of finishing at a second appointment are numerous. The patient and operator are not tired or anaesthetized. The patient will have had time to develop a more objective opinion about the restorations, this is less likely to happen at the first appointment.
After listening to the patients feedback final gross alterations may be made. These might include refining the patients occlusion and checking excursive occlusal contacts, adjustments of form that relate to the views of the patient and the clinician.
Once gross or primary alterations have been completed, secondary anatomical features such as labial groves and gross surface topography can be developed. It is helpful to map theses features with a pencil, so they are developed in a more or less symmetrical and controlled manner.
A rough grit flame shaped diamond bur can be used to develop these features either in a high speed or reduction hand piece, care should be taken not to create too much regularity to the features and the study of natural tooth forms is essential to develop natural shapes.
Once this is completed, the secondary features will need to be softened to look more natural, the grey Astropol polisher from Ivoclar is useful for this purpose. This bur will both polish and remove material, so it can be used to soften forms, complete the primary polish and be used to shape anatomical features.
At this point the perikymata (and other tertiary features) are added using a red band flame shaped diamond bur with gently sweeping horizontal movements across the facial surface of the tooth.
These markings will need to be further softened with the grey Arostopol polisher.
The polish is completed using the Kerr silicone polishers sequentially.
Note, all shaping and polishing is done with out irrigant so that the operator can watch the changes each bur and polisher is performing.
Before and after treatment views.
Images before and after orthodontics and restorative care.
Lateral views of the completed work.
Composite resin can provide an aesthetic and functional solution for managing worn teeth, however in a bruxing patient fracture and wear can present as problems and a night guard should be recommended for this type of patient.