Restoration of a posterior tooth in two parts Author: Dr Knut Hufschmidt, Wels/Austria The benefit of fissure sealing in molars, premolars and deciduous teeth is a topic of ongoing debate. This article highlights the need for effective protection. Sealing the fissures of permanent molars and premolars and of deciduous teeth continues to be a contentious subject. Nevertheless, within the framework of a sound preventive treatment strategy, fissure sealing represents a state-of-the-art solution for maintaining a caries-free dentition. On the basis of a clinical example, this article makes the case for protecting a few teeth too many than a few too little with this non-invasive treatment modality. Fissure sealing is painfree, affordable and highly effective in the long term. These reasons should outweigh any concerns about “overtreatment”. Incipient caries can damage the tooth structure and the pulp. In the worst case scenario, the tooth may have to be extracted. Case history The twelve-year-old patient presented to our practice for the first time in December 2013. At that time, she came for a routine examination. The panoramic radio graph taken during this appointment revealed a mixed dentition typical for tooth 36 (Fig. 1). All the permanent teeth including the wisdom teeth were completely formed. During the clinical inspection, discolouration was identified around the fissures of tooth 36 (Fig. 2). All the other teeth were free of caries. The clinician who had previously treated the patient had not sealed the occlusal surfaces.
Tooth 36 reacted sensitively to the pulp vitality test. The percussion test did not reveal any irregularities. The young patient and her mother were informed about the large size of the lesion and its proximity to the root canal as well as about the possible necessity of root canal treatment. The aim was to excavate the caries, fill the tooth using minimally invasive methods and keep the tooth alive in the process. Due to the urgent nature of the case, an appointment was made for the immediate future. Minimally invasive treatment of tooth decay is of utmost importance in preventive restorative therapy. The adhesive technique and the corresponding filling methods involving materials such as the composite resin Tetric EvoCeram® Bulk Fill, which was used in this specific situation, provide the clinician with optimal tools for this task. Caries excavation Since the young patient had not undergone any significant dental treatment previously, she was given a nerve block anaesthetic in order to ensure an uninterrupted and stressfree treatment session. A rubber dam was placed to give optimum access to the cavity and to keep the working field completely dry (Fig. 3). As a result of the extensive occlusal lesion, which is visible in the X-ray, a relatively large openingwas created to gain access to the cavity (Fig. 4). The picture that was presented was typical of hidden caries. The affected dentin, which was extremely soft, was roughly enamel surfaces had already been undermined to a large extent. When a minimally invasive approach is taken, the area that needs to be treated is often difficult to see. In order to ensure the complete removal of the infected tissue in this tooth, therefore, the access opening to the cavity was enlarged and the carious dentin structure was stained with a disclosing agent (Fig. 6).
Two-part filling treatment In the present case, it was possible to preserve the distal enamel wall of the affected tooth. The minimally invasive treatment composed of caries removal and tooth filling involved two parts. The first part focused on completely removing the carious tissue adjacent to the distal enamel wall. All the carious tissue had to be carefully removed at the enamel-dentin junction without perforating the enamel tooth structure. Once this treatment step had been successfully concluded (Figs 7 and 8), the ultra-thin enamel wall was acid etched and then reinforced using a dentin adhesive (Syntac® Classic) and a flowable composite (Tetric® EvoFlow) (Fig. 9). The second part of the treatment concentrated on the excavation of the carious dentin near the pulp. Utmost care had to be taken not to open the pulp cavity (Fig. 10).
Therefore, a caries disclosing agent was also used to stain the affected dentin tissue, which was then very judiciously removed to prevent pulp exposure (Pulpa aperta). Even minimal opening of the pulp could have endangered the vitality of the tooth and entailed root canal treatment. Bulk-fill restoration The quality of the restorative treatment not only depends on the proper preparation of the tooth, but also on the appropriate choice of the filling material and a precise working protocol. After the caries had been excavated in this case, tooth 36 was restored with the direct bulk-filling technique using Tetric EvoCeram Bulk Fill. This nanohybrid composite is easy to sculpt and contour. The restorations are esthetic due to the material’s lifelike translucency and shade. According to the manufacturer, a polymerization booster named Ivocerin® has been incorporated into the 10 material. As a result, the composite resin can be completely polymerized in increments of up to 4 mm thickness within 10 seconds. In addition, a special shrinkage stress reliever in the material reduces shrinkage stress to a minimum. This composite resin is very interesting for practitioners due to the efficiency and reliability of the bulk-filling technique. Nevertheless, adhesive restorations are technique sensitive and should be placed with due care. In the situation at hand, a distance of 7 mm was measured between the deepest point of the cavity and the occlusal marginal ridge using a periodontal probe. In the first filling step, the cavity was conditioned with phosphoric acid. For this purpose, the acid was selectively applied along the enamel margin (Fig. 11). After 15 seconds, the entire dentin surface was coated with etching gel. The acid was left to react for another 15 seconds. Next, the dentin adhesive (Syntac Classic) was applied, followed by the first composite (Tetric EvoCeram Bulk Fill) increment in shade IVA (universal A shade). The remaining depth of the cavity now measured about 4 mm. The composite resin was polymerized for 10 seconds with Bluephase® G2. Then, the second increment was placed. The cavity was filled completely and the chewing surface of the tooth was contoured. The excellent moulding properties of the material allowed a functional and natural-looking restoration to be efficiently produced. The restoration was polymerized for a final 10 seconds. Finishing Before the rubber dam was removed, a scalpel was used to roughly remove the excess material at the filling margins and a Soflex disc was used for finishing the restoration. Then, the surface was polished with silicone polishers (Fig. 12). The rubber dam was removed and the occlusal and laterotrusive movements were checked and the necessary adjustments were made.
A direct comparison of the preoperative situation (Fig. 2) and the completed restoration clearly shows that the original tooth shape and the anatomic features of the chewing surface have been restored in accordance with the original appearance of the tooth. The X-ray of the final situation shows the tight radiopaque filling close to the pulp (Fig. 13). All the other proximal surfaces are free from carious lesions. In order to prevent the occurrence of further occlusal surface caries, all the erupted molars and premolars were sealed with Helioseal® Clear (Fig. 14).
Conclusion The present case once again highlights the importance of sealing the occlusal surfaces for preventive reasons. Furthermore, direct composite restorations have become indispensable in the treatment of carious lesions according to minimally invasive methods. The adhesive approach is today’s preferred technique for repairing small and even some largish defects. The adhesive technique is versatile, allows maximum preservation of the tooth structure and stabilizes the affected tooth. In situations, where a considerable amount of tooth structure has been lost, the efficient bulk-filling technique provides an economical solution. The polymerization booster contained in the material used to treat our patient minimizes the risk of obtaining inadequate polymerization results. Fillings in very deep cavities can be effectively and reliably cured. In terms of their appearance, modern bulk-fill materials are just as esthetic as their traditional hybrid composite counterparts due to their excellent ability to blend in with the natural dentition.