Single crowns versus conventional fillings for the restoration of root filled teeth
Abstract
Background
Endodontic treatment, involves removal of the dental pulp and its replacement by a root canal filling. Restoration of root filled teeth can be challenging due to structural differences between vital and non‐vital root filled teeth. Direct restoration involves placement of a restorative material e.g. amalgam or composite directly into the tooth. Indirect restorations consist of cast metal or ceramic (porcelain) crowns. The choice of restoration depends on the amount of remaining tooth which may influence long term survival and cost. The comparative in service clinical performance of crowns or conventional fillings used to restore root filled teeth is unclear.
Objectives
To assess the effects of restoration of endodontically treated teeth (with or without post and core) by crowns versus conventional filling materials.
Search methods
We searched the following databases: the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE via OVID, EMBASE via OVID, CINAHL via EBSCO, LILACS via BIREME and the reference lists of articles as well as ongoing trials registries.There were no restrictions regarding language or date of publication. Date of last search was 13 February 2012.
Selection criteria
Randomised controlled trials (RCTs) or quasi‐randomised controlled trials in participants with permanent teeth which have undergone endodontic treatment. Single full coverage crowns compared with any type of filling materials for direct restoration, as well as indirect partial restorations (e.g. inlays and onlays). Comparisons considered the type of post and core used (cast or prefabricated post), if any.
Data collection and analysis
Two review authors independently assessed trial quality and extracted data.
Main results
One trial judged to be at high risk of bias due to missing outcome data, was included. 117 participants with a root filled premolar tooth restored with a carbon fibre post, were randomised to either a full coverage metal‐ceramic crown or direct adhesive composite restoration. At 3 years there was no reported difference between the non‐catastrophic failure rates in both groups. Decementation of the post and marginal gap formation occurred in a small number of teeth.
Authors' conclusions
There is insufficient evidence to support or refute the effectiveness of conventional fillings over crowns for the restoration of root filled teeth. Until more evidence becomes available clinicians should continue to base decisions on how to restore root filled teeth on their own clinical experience, whilst taking into consideration the individual circumstances and preferences of their patients.
PICOs
Plain language summary
Single crowns or routine fillings for the restoration of root filled teeth
Root filling is a fairly routine dental procedure in which the injured or dead nerve of a tooth is removed and replaced by a root canal filling. However, the restoration of root filled teeth can be quite challenging as these teeth tend to be weaker than healthy ones. A dentist may use crowns (restorations made outside of the mouth and then cemented into place) or conventional fillings (direct filling with materials such as amalgam or composite/plastic resin). Although crowns may help to protect root filled teeth by covering them, conventional fillings demand less in terms of time, costs and removal of tooth structure.
This review included one study with 117 participants in which a tooth (117 premolars) received a carbon fibre post and was restored with either a fused porcelain to metal crown or a routine white filling. The study was of short duration and included a relatively small number of participants and was assessed as at high risk of bias. Based on this single study, there is currently insufficient reliable evidence to support which of these treatments are more effective.
Future research should aim to provide more reliable information which can help clinicians to decide on appropriate treatment whilst taking into consideration the individual circumstances and preferences of their patients.
