Re-establishing a stable occlusion in a tipped second molar

Case by Dr. Salvatore Scolavino

The establishing of a stable occlusal relationship is one of the biggest challenges dental practitioners are facing when restoring posterior teeth with resin composite, but it is a task with a decisive impact on the integrity of the masticatory apparatus. A poor static and dynamic occlusion may have a negative effect on the restored tooth, the periodontal apparatus, and also on the opposing dentition.¹ Ideally, the occlusal anatomy of direct restorations is designed in a way that occlusal forces are directed along the long axis of the tooth, which is achieved when each cusp tip in occlusal contact touches a flat surface. Horizontally directed forces, on the other hand, should be avoided, as they tend to cause tipping and increase the risk of cuspal fracture, tooth mobility etc.

In cases concerning improper occlusal relationship involving tipping of restored teeth, it may be possible to stabilize the situation by replacing the restoration and re-establishing a proper occlusion. If carried out correctly and early enough, this restorative approach may be a way around orthodontic treatment. The following clinical case is used to demonstrate how to create a functional occlusal surface right away – without larger adjustments. The whole restorative procedure is simplified by the use of a universal composite with a single posterior shade that eliminates the need for shade determination and shade selection, while it produces lifelike treatment outcomes.

Case description

This patient presented with direct composite restorations in the mandibular left first and second molar that were lacking an elaborated occlusal morphology (Fig. 1). The second molar appeared to be tipped mesially towards the first molar (Figs. 2 and 3), which resulted in improper occlusal relationships and a decreased position of the mesial marginal ridge. In order to verify the clinical and radiographic observation of an improper occlusal relationship, the occlusal contacts were recorded with articulating paper (Fig. 4). As expected, there was an uneven distribution of occlusal contacts, which were exclusively located in the distobuccal area on the second molar, and not matching the tooth-restoration interface on both molars.

Fig. 1. Pre-operative clinical situation: Occlusal view.

Fig. 2. Pre-operative clinical situation: Lateral view revealing the tipping of the second molar.

Fig. 3. Pre-operative bite-wing radiograph confirming the tipping issue.

Fig. 4. Checking of the occlusal contacts.

Planned approach

As orthodontic treatment was not an option, it was decided to replace the composite restorations, thereby treating the Class I cavity of the second molar as if it were a Class II cavity. This would allow us to increase the height of the mesial marginal ridge and establish the proper occlusion.

Preliminary measures

Once the rubber dam was placed (Fig. 5), the existing composite restorations were removed and the cavity slightly extended with a diamond chamfer bur (Fig. 6). The result of this procedure is shown in Figure 7. In order to provide an anatomical build-up of the mesial wall, a sectional matrix was mounted with the aid of a wooden wedge and a separator ring (Fig. 8).

Fig. 5. Isolation with rubber dam, held in place with a clamp and a wedge.

Fig. 6. Tooth preparation with a diamond chamfer bur.

Fig. 7. Appearance of the teeth after preparation.

Fig. 8. Sectional matrix, wedge and separator ring in place.

Adhesive procedure

After selective etching of the enamel (K-ETCHANT GEL, Kuraray Noritake Dental Inc.) (Fig. 9), the enamel bonding surfaces had a chalky-white appearance, which indicates properties that are favourable for bonding (Fig. 10). The adhesive procedure was performed with CLEARFIL™ SE BOND 2 (Kuraray Noritake Dental; Fig. 11). In the first step, the primer of the system was applied and actively rubbed into the surface for 40 seconds, and air-dried. Subsequently, the bond was used in the same manner. After complete evaporation of the solvent, the bonding surface was light-cured for 40 seconds to ensure proper polymerisation. The cavity floor was then covered with a 1 mm thick layer of flowable composite (CLEARFIL MAJESTY™ ES FLOW SUPER LOW A3, Kuraray Noritake Dental).

Fig. 9. Selective etching of the enamel.

Fig. 10. Chalky-white enamel surfaces.

Fig. 11. Glossy appearance of the bonding surfaces after application of the tooth primer and bond.

Restoration procedure

Before starting to elevate the mesial wall of the second molar using the centripetal build-up technique² (Fig. 12), we analyzed the height of the marginal ridge and anatomical details of the contralateral tooth, while the adjacent molar provided orientation as well. In general, knowledge not only about the tooth’s typical anatomy, but also about the patient-specific anatomical details of the adjacent and contralateral teeth as well as the antagonist is very useful for designing the occlusal anatomy. In addition, remaining anatomical structures should be read and used. In this particular case, the restorations were completed with CLEARFIL MAJESTY™ ES-2 Universal composite (Kuraray Noritake Dental) in the posterior shade U, using the cusp-by-cusp technique (Figs. 13 to 15). In most areas, it was possible to follow the inclination of the remaining cusps and the orientation of the grooves to produce an ideal surface anatomy. For those who would like to speed up the procedure, the simultaneous modeling technique³ may be an option. In this technique, the cusps are built up simultaneously from separate increments, which remain out of contact to each other until light-cured in a single curing cycle.

Fig. 12. Mesial wall built up with composite.

Fig. 13. Application of the first increment for cusp build-up. It is useful to limit the size of the increments for controllability.

Fig. 14. Cusp-by-cusp build-up completed on the second molar.

Fig. 15. Molars with restored occlusal surfaces.

In order to improve the already great optical integration of the restorations, some stain (Dark Brown, CHROMA ZONE™ COLOR STAIN, Kuraray Noritake Dental) was applied to the fissures. A multi-blade ball shaped bur and an Arkansas Flame abrasive stone were used for finishing. Final polishing was accomplished with the TWIST™ DIA system (EVE). The immediate treatment outcome is shown in Figure 16. The patient was released after rubber dam removal, checking the static and dynamic occlusion, and conducting a control radiograph (Fig. 17). The optical integration was even better at the recall after one month due to the rehydration of the surrounding tissues (Fig. 18), while the functional integration was excellent and no occlusal adjustments were required.

Fig. 16. Immediate treatment outcome with a nice optical integration of the restorations providing for a stable occlusal relationship.

Fig. 17. Control radiograph taken after the direct restoration procedure.

FINAL SITUATION

Fig. 18. Treatment outcome at recall after 30 days.

Conclusion

The presented case example reveals how important it is to strive for occlusal stability when restoring posterior teeth with composite. Furthermore, it demonstrates how it is possible to re-establish a stable occlusal relationship, even if some tipping has already occurred. In order to get it right the first time, it is essential to make use of the remaining anatomical structures, which guide the way toward an occlusal surface that ensures a favourable distribution of occlusal forces, and therefore provides optimal conditions for a long life of the freshly restored teeth. The combined use of the presented restorative techniques with innovative materials like CLEARFIL MAJESTY™ ES-2 Universal will make the procedures simpler and even more efficient.

References

1 Sandhu S, Lal J, Singh R, Sandhu R, Sra J. Significance of establishing occlusal anatomy in operative dentistry. Saint Int Dent J 2016;2:7-10.
2 Bichacho N. The centripetal build-up for composite resin posterior restorations. Pract Periodontics Aesthet Dent. 1994 Apr;6(3):17-23.
3 Scolavino S, Paolone G, Orsini G, Devoto W, Putignano A. The Simultaneous Modeling Technique: closing gaps in posteriors. Int J Esthet Dent. 2016 Spring;11(1):58-81.

Dentist:

DR. SALVATORE SCOLAVINO

Dr. Salvatore Scolavino, graduated with honors in Dentistry and Dental Prosthesis from the University of Naples. Dr. Salvatore is a specialist in aesthetics and direct and indirect anterior and posterior adhesive restorations. His focus lies with Conservation, Endodontics and Prosthetics in particular. He is an active member of prestigious academies and scientific societies: AIC -Italian Academy of Conservation, IAED -Italian Academy of Esthetic Dentistry and SIDOC (Italian Society of Conservative Dentistry. Since 2004, he has private practice Nola, Italy.

Dr. Scolavino is a founder of werestoreit.it, an inspiring site that offers abundance and variety of aesthetic clinical cases. Author of the book published by Quintessence Publishing „Direct Restorations in the posterior regions“, author of scientific publications in national and international journals, he is speaker at courses and conferences in Italy and abroad.

• Oct 5, 2021

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