Clinical Evaluation of Bonded Amalgam Restorations in Endodontically Treated Premolar Teeth: A One-Year Evaluation

Abstract

Aim: The aim of this clinical study was to compare the fracture resistance, marginal adaptation, and rate of recurrent caries of bonded and nonbonded amalgam restorations in endodontically treated premolar teeth. Methods and Materials: A total of 36 patients with endodontically treated maxillary first or second premolars were selected and divided into three groups. The treatments in all groups consisted of lingual cusp coverage and cementation of a prefabricated intracanal post (No. 2 long, Dentatus USA, New York, NY, USA). One type of cavity liner was used for each group as follows: copal varnish (Group A), Amalgambond Plus (Group B), and Scotchbond MultiPurpose (Group C). The teeth were then restored with Cinalux high-copper spherical amalgam (Cinalux, Sh. Dr Faghihi Dental Co., Tehran, Iran). After one year, fracture resistance, marginal adaptation, and secondary caries were evaluated. Fischer's exact test was used for statistical analysis using a 0.05 percent significance level. Results: There was no significant difference among groups with respect to fracture resistance (p=0.49). However, significant differences in marginal adaptation existed among the three groups (p=0.02) and no recurrent caries were found in any of the restored teeth. Conclusion: Bonding amalgam restorations using Amalgambond Plus and Scotchbond MultiPurpose Plus did not improve the fracture resistance or affect the resistance to secondary caries in endodontically treated premolar teeth. However, the teeth in both these bonded groups showed significant improvement in marginal adaptation compared with restorations placed with copal varnish (p=0.02). Clinical Significance: Amalgambond Plus or Scotchbond MultiPurpose adhesive resins significantly improved marginal adaptation of amalgam compared with copal varnish, but did not enhance fracture resistance or affect the prevention of secondary caries.

Fracture Resistance of Endodontically Treated Premolars Reconstructed by Traditional Casting and CAD-CAM Milling Post and Cores

“…is is especially true for premolars, as these teeth usually have insufficient dentin after endodontic therapy and thus require root canal retention for the long-term maintenance of restorations and minimizing the possibility of fracture [9,10]. Different types of posts are available for enhancement of endodontically treated teeth such as cast posts, prefabricated metal posts, and fiber-reinforced composite posts.…”

“…In cases with sufficient dentin, it is better to supply retention from the pulp chamber, but if a great extent of dentin has been lost as a result of extensive caries, previous restorations, or access cavity preparation, the application of posts for enhancing the internal strength of the teeth is inevitable [ 8 ]. This is especially true for premolars, as these teeth usually have insufficient dentin after endodontic therapy and thus require root canal retention for the long-term maintenance of restorations and minimizing the possibility of fracture [ 9 , 10 ].…”