Incorporating minimally invasive principles into the aesthetic management of fractured anterior teeth.
Maximum preservation of affected tissues, which have the potential to heal and return to a state of normal health and function, is the basic principle of modern minimally invasive techniques. A care plan should always be designed with the longevity of the tooth in mind, not restorative replacement. In a prepared tooth, the size of the preparation is inversely proportional to the fracture resistance of the tooth structure. Furthermore, no restoration lasts a lifetime. Even a meticulously made restoration is pushed into a cycle of re-restoration. Therefore, avoiding unnecessary large preparations is of paramount importance.
Developments and innovations in the field of materials science are extremely useful in the realization of minimally invasive (MI) tooth preparations. Over the years, the aesthetic properties of direct restorative materials have constantly evolved. Nanotechnology has played an important role in the field of aesthetics by modifying the particle size of contemporary composites (ranging from 1-10nm) to match that of hydroxyapatite crystals. This helps to provide a bonded interface between the tooth and the material that is close to the natural one.
Some systems use different combinations of nano-fillers and prepolymerized fillers to reduce polymerization shrinkage, increase fracture toughness, improve polishability, and match wear resistance to natural teeth (Trimodal technique used in Premise, Kerr Dental). Polychromatic materials help to realistically replace lost tooth surfaces. The color and opacity of the material determine its clinical application. Overlay resins with different compositions helps to achieve natural tooth-like restorations with similar reflective and refractive properties. Most of the above-mentioned features are incorporated in contemporary materials available on the market.
Contemporary adhesive systems shows a high degree of conversion in etched substrates as well as in smear layer loaded substrates, thus supporting MI preparations. Initiators play a key role in optimizing the degree of conversion. It is believed that dual-curing systems, which contain both photopolymerizable and chemical polymerization initiators, stimulate polymerization and thus increase the degree of conversion. Monomers adhesion promoters such as 4-MET, 10-MDP and MAC-10 have revolutionized the dental field through their ability to form ionic bonds with calcium.
Case presentation
A 40-year-old man presented with an uncomplicated traumatic fracture of the left maxillary central incisor. The patient also reported that the tooth had been asymptomatic since the day of the fracture (approximately two years). He was concerned about his smile and was anxiously awaiting an esthetic replacement for the missing tooth fragment.
Special test
An intraoral periapical radiograph was performed and sensitivity tests were done to arrive at a confirmatory diagnosis.
The sensitivity test results of the affected tooth corresponded to those of the control tooth, confirming the absence of pulp inflammation.
Restorative care
Based on the results of special tests, the decision was made to restore the tooth with resin composite. The reason being that they offer good aesthetic results with acceptable longevity. Combined with minimal preparation, the damage to the tooth would be negligible compared to the other options. The physical properties of the resin also made it a suitable choice. Micro and nano composite fillings are available in different shades of dentin and enamel, along with coloring resins that help create a perfect surface texture.
The first step in the aesthetic replacement of a fractured tooth fragment is color selection. Shade selection was done in ambient daylight using a custom shade guide. After shade selection, isolation of the working field was performed using a rubber dam. The fractured tooth was ground. Chamfering was followed by etching with orthophosphoric acid 37%. Part of the aprismatic enamel (cervical to the beveled surface) was also etched to facilitate an esthetic result (to avoid a demarcated edge at the restoration-tooth interface). Adjacent teeth were protected by transparent matrices during the etching process. 7th generation adhesive was applied to the surface using an air-dried microbrush for 5-10 seconds and then polymerized for 20 seconds.
To restore the tooth, it was used microhybrid composite. The layering technique was used, and the flat plastic was the instrument used to place the composite and shape the restoration. Medium dentin and light enamel were layered to mimic the natural shape and shade of the tooth. Coarse sculpting was done with composite finishing burs, and polishing was completed with the Rainbow polishing disc and polishing paste.
Why composites for M(I)Y restorative procedures
The main advantage of direct composites is that they require minimal tooth preparation for their placement. They are relatively pulp-friendly and are the easiest to reshape, presenting fewer challenges in terms of repair. Their wear resistance is comparable to that of natural teeth and therefore reduce the risk of tooth wear on opposing/occlusal teeth (compared to other available materials). Secondary and tertiary surface textures can also be incorporated into the restoration. They are generally completed in a single visit and therefore do not require the placement of provisional restorations. Despite the fact that they give refined results, these procedures are available at a low financial cost.
However, these restorations also have some disadvantage, including postoperative hypersensitivity, marginal discoloration, adhesive failure, and reduced longevity. However, the material supports resurfacing and localized repair, which would help overcome some of these disadvantages.
Conclusion
Traditional restorative management of diseased/fractured teeth results in irreversible loss of dental hard tissues, which forces them into a repetitive cycle of restoration and re-restoration that ultimately weakens the teeth. MI management aims to preserve the tooth structure as much as possible, using minimally invasive surgical procedures and contemporary bonding materials. However, the success of treatment is directly related to the patient’s motivation and understanding of the disease process and its management. Therefore, MI restorative treatments combined with appropriate patient education is the best way to manage teeth that require restorative care.
Source: enlightensmiles.com
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