Treating a Fractured Molar

A 57-year-old male patient presented to the office with the chief complaint that he experienced discomfort in the maxillary right posterior region when chewing. He reported that he had heard a cracking noise from his upper right side while eating soft food, which was followed by pain and discomfort. Upon examination, his maxillary right first molar (tooth No. 3) was found to be fractured (Figure 1). Due to the nature of the fracture and the integrity of the remaining natural tooth structure, root canal treatment followed by crown lengthening and delivery of a full coverage zirconia crown was the chosen procedural pathway.

Clinical Procedure: Phase 1

The first step in the treatment plan was to address the fractured tooth's pulp and prevent infection. Therefore, the root canals were carefully accessed and medicated with calcium hydroxide to disinfect, promote healing, and ensure the tooth's vitality (Figure 2). To ensure a stable foundation for the final restoration, crown lengthening was necessary to expose more of the tooth structure above the gumline. This was achieved using a dental soft and hard tissue laser system (Waterlase iPlus^®, BIOLASE). Dental lasers are known for their precision and minimal invasiveness, which makes them an excellent choice for delicate soft-tissue procedures such as crown lengthening.¹

In this case, the biologically oriented preparation technique (BOPT) was utilized to prepare the tooth for the final restoration.² The clinician opted for this feather-edge preparation to preserve as much of the viable tooth structure as possible. Next, to restore the tooth's shape and structure, the clinician used a core buildup material (CLEARFIL DC CORE PLUS, Kuraray Noritake) designed to provide excellent adhesion and strength, which was essential in creating a durable foundation for the final restoration (Figure 3).

Following the buildup, a digital impression was acquired (Primescan^®, Dentsply Sirona) (Figure 4), and a temporary crown made from a hybrid CAD/CAM block (KATANA AVENCIA Block, Kuraray Noritake) was placed to facilitate tissue healing and contouring, preparing the gingiva for the placement of the final restoration.

Clinical Procedure: Phase 2

Considering the deep margin and tissue attachment of the temporary restoration, a zirconia block (KATANA^™ Zirconia ONE, Kuraray Noritake) was selected as the most appropriate material for the final restoration. Zirconia is known for its excellent biocompatibility and favorable tissue response, which reduces the risk of irritation and inflammation and promotes a healthy and natural-looking gingival contour.³ Its high strength and durability also help to enhance the restoration's longevity.⁴

The design of the final restoration was achieved digitally using CAD/CAM software (CEREC^® SW 5.2.8, Dentsply Sirona). During the design phase, specific adjustments were made to the parameters to achieve a perfect crown design (Figure 5). One crucial modification involved increasing the marginal thickness to 140 µm (Figure 6). This modification ensured a robust and well-defined margin to help prevent chips or fractures in the restoration.

After the design was completed, the zirconia block was milled using an extra fine milling strategy (CEREC^® Primemill, Dentsply Sirona) to ensure accuracy and surface smoothness in the restoration, resulting in a high-quality final product (Figure 7). Before the sintering process, the restoration was polished (Twist Polishers, Meisinger USA) to enhance the material's surface smoothness, improving the overall esthetics and fit of the restoration (Figure 8). Once milled and polished, the restoration was sintered (CEREC SpeedFire, Dentsply Sirona). The sintered crown was then hand polished (Pearl Surface Z, Kuraray Noritake) to achieve a pearly luster, which would add to its natural appearance and complement the patient's smile beautifully.

Proper cementation of the final crown was crucial to ensure its long-term success and stability. To enhance the bonding surface of the crown, its intaglio surface was sandblasted. The tooth receiving the crown was also prepared using an intraoral sandblaster to ensure a strong and reliable bond between the tooth and the cement. A universal adhesive (CLEARFIL^™ Universal Bond Quick, Kuraray Noritake) was then scrubbed onto the prepared tooth's surface for approximately 30 seconds, ensuring even coverage. For the final cementation of the crown, a self-adhesive resin cement (PANAVIA^™ SA Cement Universal, Kuraray Noritake) was used.

After the crown was accurately positioned, each of its surfaces was light cured for 20 seconds. The interproximal contacts were then checked to ensure that there were no tight spots or impingements, and any excess cement was carefully removed to prevent gum irritation and maintain proper contours around the restoration. Finally, the patient's bite was checked to ensure that it was balanced and functional. Any high spots or interferences were adjusted to achieve an ideal occlusal relationship.

The patient reported that he was thoroughly satisfied with his restored tooth (Figure 9). He was provided with postoperative instructions, which emphasized regular dental checkups and cleanings to monitor the crown's health and prevent any potential issues.

Through the utilization of cutting-edge dental materials, advanced technology, and meticulous clinical procedures, the clinician successfully achieved the treatment goals of preserving the natural tooth and providing a biocompatible restoration with excellent esthetics and function. By taking a patient-centered and evidence-based approach, an optimal outcome was achieved.

Daniel Vasquez, DDS
Private Practice
Oceanside, California

Kuraray America, Inc.
kuraraydental.com
800-879-1676