Cast post and core foundation for the badly broken down molar tooth

A novel and easy technique for restoring grossly decayed mandibular molar with a modified cast-post

The article addresses the difficulty of restoring a grossly carious molar tooth, where very little tooth structure is left after caries excavation. When enough sound tooth structure is missing for satisfying the ferrule effect, a clinician can follow this technique and easily restore such teeth. A step by step procedure, including instrumentation and materials and a new impression technique, is described in detail, with clinical photographs. This technique results in the fabrication of a robust and extremely retentive post and core on which to place fixed prosthodontic restorations. A 2 and half year study showed that the tooth well in function with no signs of any problem. The author has restored around many decayed molars using this technique. Over a period of three years, no failure was reported. With an increasing demand on the dentist for restoring a structurally compromised teeth, this technique provides the patients with a robust prosthodontic solution.

Is the glass half empty or half full? A novel "philosophical" approach to the "mystery" of the so-called ferrule effect

The prognosis of endodontically treated teeth has traditionally been associated with the presence of the so-called ferrule effect that is generally related with the presence of a minimum of 1-2 mm of sound tooth structure at the cervical area of parallel axial walls that totally encircle the tooth. Even though all of these factors are well desired, one should question if their absence should condemn a tooth and compel extraction as the only logical treatment plan option. For this reason an hypothesis is being formed that associates the aforementioned factors not with the presence of the so-called ferrule effect, but rather with the resistance form of the preparation that is being provided by the sound tooth structure at the cervical area of the tooth. When the desired resistance form is provided by sound tooth structure of endodontically treated teeth, then less lateral forces are being transferred to the post & core and subsequently to the root of the teeth, thus minimizing the chances of decementation of the post & core or worst fracture of the root. Even more important, if this hypothesis may be further entertained, then even when the so-called ferrule effect is not present, the teeth may not be extracted, but alternative strategies for post & core restorations may be investigated, such a more flexible carbon- or glass-fiber posts & core build ups made from flowable resin composite that may accommodate for the increased lateral forced exerted to the post & core complex during function.

WITHDRAWN: Root canal posts for the restoration of root filled teeth

BACKGROUND

The foundation for the reconstruction of endodontically-treated teeth can be provided by a metal or a non-metal post and core system but no guidelines exist for choosing one or the other in particular clinical cases.

OBJECTIVES

To assess the effectiveness of different post and core systems for the restoration of endodontically-treated teeth. The primary objective of this review was to compare the clinical failure rates of the different types of posts.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, Issue 3), MEDLINE (from 1966 to September 2005), Scopus (from January 1985 to December 2004) and EMBASE (until December 2004). We looked through reference lists of articles and dental conference proceedings. We contacted researchers in the field and manufacturers.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials (RCTs) comparing failures on endodontically-treated permanent teeth with different types of post. The outcomes were loss of retention, post fracture and root fracture.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the quality of trials and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Two trials involving 317 participants were included but only one of them, involving 200 participants, compared metal to non-metal posts. The other answered to the secondary objective. The risk of failure was greater with metal-cast posts (9/98) compared to carbon fibre posts (0/97) (risk ratio (RR) = 0.05 (95% confidence interval (CI) 0.00 to 0.90)) but the study was at high risk of bias. Thus fewer failures occurred when using non-metal posts but the evidence is unreliable.

AUTHORS' CONCLUSIONS

Our systematic review could not specify which type of post and core system should be used when two or three dentine walls remain. More RCTs are needed to confirm whether fibre-reinforced post and core systems are superior and to clarify the influence of the remaining tooth structure on the treatment outcome of the different post and core systems available. Well-defined inclusion criteria focusing on the number of dentine walls (two or three) should be used.

Management of Grossly Decayed Mandibular Molar with Different Designs of Split Cast Post and Core

Mandibular molar with extensive loss of tooth structure, especially where no cavity wall is remaining, and insertion of posts in both the roots appear necessary so as to achieve proper retention for the core material. A single unit metal casting with two posts, one in the mesial root and the other in the distal divergent root, is difficult to fabricate due to difference in the path of insertion of the two posts. Multisection post and core or single cast post and core with auxiliary post can be an effective design to manage grossly decayed mandibular molars.

Management of grossly destroyed endodontically treated teeth with lock and key custom modified cast post and core design: A case series

The purpose of this paper is to demonstrate a more retentive custom modified lock and key design of metal cast post and core for the restoration of grossly destroyed endodontically treated molar tooth. The lock and key metal cast post consists of two parts, one in the distal canal (primary post) and the other one in mesio-lingual canal (secondary post). The primary post has a lock design, while the secondary post contains the key design, both of which interlock together. Lock and key cast post, mentioned in this report can be an effective design for the management of grossly destroyed molar teeth.

Root canal posts for the restoration of root filled teeth

BACKGROUND

The foundation for the reconstruction of endodontically-treated teeth can be provided by a metal or a non-metal post and core system but no guidelines exist for choosing one or the other in particular clinical cases.

OBJECTIVES

To assess the effectiveness of different post and core systems for the restoration of endodontically-treated teeth. The primary objective of this review was to compare the clinical failure rates of the different types of posts.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, Issue 3), MEDLINE (from 1966 to September 2005), Scopus (from January 1985 to December 2004) and EMBASE (until December 2004). We looked through reference lists of articles and dental conference proceedings. We contacted researchers in the field and manufacturers.

SELECTION CRITERIA

Randomised or quasi-randomised clinical trials (RCTs) comparing failures on endodontically-treated permanent teeth with different types of post. The outcomes were loss of retention, post fracture and root fracture.

DATA COLLECTION AND ANALYSIS

Two review authors (Michele Muller-Bolla (MMB) and Cybele Borg (CB)) independently assessed the quality of trials and extracted data. Study authors were contacted for additional information.

MAIN RESULTS

Two trials involving 317 participants were included but only one of them, involving 200 participants, compared metal to non-metal posts. The other answered to the secondary objective. The risk of failure was greater with metal-cast posts (9/98) compared to carbon fibre posts (0/97) (risk ratio (RR) = 0.05 (95% confidence interval (CI) 0.00 to 0.90)) but the study was at high risk of bias. Thus fewer failures occurred when using non-metal posts but the evidence is unreliable.

AUTHORS' CONCLUSIONS

Our systematic review could not specify which type of post and core system should be used when two or three dentine walls remain. More RCTs are needed to confirm whether fibre-reinforced post and core systems are superior and to clarify the influence of the remaining tooth structure on the treatment outcome of the different post and core systems available. Well-defined inclusion criteria focusing on the number of dentine walls (two or three) should be used.