Presentation on theme: "Restoration of endodontically treated tooth. Amalgam, resin composite, and glass ionomer in combination with a prefabricated post Amalgam had the lowest."— Presentation transcript:
Restoration of endodontically treated tooth
Amalgam, resin composite, and glass ionomer in combination with a prefabricated post Amalgam had the lowest failure rate, Glass ionomer core buildup materials caused the greatest number of failures R. E. Kovarik, L. C. Breeding, and W. F. Caughman, Fatigue life of three core materials under simulated chewing conditions, The Journal of Prosthetic Dentistry, vol. 68, no. 4, pp. 584–590, 1992
Some studies supported the use of amalgam dowels in the root canals Tamse compared 49 mesial roots extracted due to vertical fractures with 52 mesial mandibular roots without fractures, and found that 67.3% of the vertically fractured roots had an amalgam dowel in the coronal part (1-2mm) of the root.
In another study, endodontically treated teeth not crowned after obturation were lost 6 times more often than teeth crowned after obturation S. A. Aquilino and D. J. Caplan, Relationship between crown placement and the survival of endodontically treated teeth, The Journal of Prosthetic Dentistry, vol. 87, no. 3, pp. 256–263, 2002.
A 10-year prospective clinical trial, showed 94% survival rate of metal post-and-cores with a crown G. Heydecke andM. C. Peters, The restoration of endodontically treated, single-rooted teeth with cast or direct posts and cores: a systematic review, The Journal of Prosthetic Dentistry, vol. 87, no. 4, pp. 380–386, 2002.
Another 17-year controlled prospective study showed that the type of core restorations under the crowns had no effect on the survival rate of 307 endodontically treated teeth W. A. Fokkinga, C. M. Kreulen, E. M. Bronkhorst, and N. H. J. Creugers, Up to 17-year controlled clinical study on postand- cores and covering crowns, Journal of Dentistry, vol. 35, no. 10, pp. 778–786, 2007.
Post-core The use of posts does not reinforce endodontically treated teeth and some reports even show that teeth which were restored without a post and core are less susceptible to fracture than teeth with post and core A. Smidt and E. Venezia, Techniques for immediate core buildup of endodontically treated teeth, Quintessence International, vol. 34, no. 4, pp. 258–268, 2003
Post-core Its success relies on the success of the entire system and vice versa. For anterior restorations, consider using a ceramic or light-colored fiber post made of quartz, silicone or glass fibers.
Post Shape Posts come in three basic shapes: parallel, tapered, and parallel-tapered
Parallel Parallel posts are more retentive than tapered ones. They seem less likely to cause root fractures, distributing stresses evenly along their length. However, parallel posts require removal of more tooth structure than tapered ones and, therefore, may not be suitable for roots with thin walls.
Tapered Tapered posts allow for minimal dentin removal since most roots themselves are tapered. The stresses absorbed by these posts are concentrated in the apex Creating a wedging effect and increasing the risk of vertical root fracture. Because of this increased risk when tapered posts fail, they are more likely to leave the tooth unrestorable.
Parallel-tapered Advantages of both designs with few reported disadvantages. This post has a parallel shaft, tapering at the apical end. This mix achieves retention associated with parallel sides, while allowing tooth preservation at the apex.
Length and Diameter Post retention improves with increases in post length, rather than diameter. An increase in post length with a minimum diameter preserves tooth structure and reduces shear stresses and risk of fracture.
Diameter is important for strength and resistance to post fracture Sequential use of post twist drills, starting with narrowest and working up to the desired post diameter, can be useful in minimizing tooth loss during post-space preparation.[
Rotational resistance in an extensively damaged tooth can be obtained by preparing a small groove in the root canal. This must be in the path of placement of the post and core. The groove is normally located where the root is bulkiest, usually on its lingual aspect.
Influence of post and cores on light transmission through all-ceramic crowns Some ceramic systems are semi-translucent (IPS Empress®, Ivoclar Vivadent) Others are semi-opaque (In-Ceram®, Vident, Brea, CA). A traditional metal post (gold or titanium) results in poor esthetics because of the lack of light transmission.
. Metallic posts also create a light blue/gray appearance at the gingival margin, possibly as a result of shadows.
Metal post Esthetic Corrosion reactions Taste Oral burning Oral pain Sensitization and other allergic reactions Hayashi Y, Nakamura S. Clinical application of energy dispersive x-ray microanalysis for nondestructively confirming dental metal allergens. Oral Surg Oral Med Oral Pathol 1994; 77:
Radiopacity FRC Postec shows reduced radiopacity Used in conjunction with Variolink II provides additional x-ray identification
Removal FRC Postec can be removed with a rotary instrument if retreatment is required
Zirconia posts Meyenberg Good chemical stability Mechanical strength High toughness Color similar to that of natural teeth Ahmad I. Yttrium–partially stabilized zirconium dioxide posts: an approach to restoring coronally compromised nonvital teeth. Int J Periodontics Restor Dent 1998; 18:
Zirconia posts Nearly impossible to remove Removal of zirconia post by ultrasonic causes temperature rise of the post and on the root surface
Zirconia post Cormier et al: fracture strength of zirconia post varied according to the different stages of tooth restoration. When the post alone was bonded into tooth, fracture strength was N; when the post was bonded into tooth with core buildup, fracture strength was N; with post and core buildup as well as full veneer restoration, fracture strength was N Cormier CJ, Burns DR, Moon P. In vitro comparison of the fracture resistance and failure mode of fiber, ceramic and conventional post systems at various stages of restoration. J Prosthodont 2001; 10:
The bond strengths of luting agents to zirconia posts were measured without bonding to any tooth structure, and it was shown that a dual-cured resin cement,Panavia (Kuraray, Osaka), produced better results than other cement types Sahmali S, Demirel F, Saygili G. Comparison of in vitro tensile bond strengths of luting cements to metallic and tooth-colored posts. Int J Periodontics Restor Dent 2004; 24:
The reviewed studies suggested that FRC and zirconia posts might be the preferred clinical choice for preventing coronal microleakage Jung SH, Min KS, Chang HS, Park SD, Kwon SN, Bae JM. Microleakage and fracture patterns of teeth restored with different posts under dynamic loading. J Prosthet Dent 2007; 98: Reid LC, Kazemi RB, Meiers JC. Effect of fatigue testing on core integrity and post microleakage of teeth restore with different post systems. J Endod 2003; 29: Usumez A, Cobankara FK, Ozturk N, Eskitascioglu G, Belli S. Microleakage of endodontically treated teeth with different dowel systems. J Prosthet Dent 2004; 92:
zirconia posts showed the highest radiodensity level, followed by metallic posts, carbon fiber posts, glass fiber posts, and carbon fiber post covered with quartz fiber.
In a study by Dietschi et al. It was reported that the carbon fiber post presented the lowest marginal gap proportion (7.11%) compared to other post types which presented higher degrees of marginal gap formation: titanium post at 11%, zirconia post at 16.5%, and stainless steel post at 17.4% Dietschi D, Ardu S, Rossier-Gerber A, Krejci I. Adaptation of adhesive post and cores to dentin after in vitro occlusal loading: evaluation of post material influence. J Adhes Dent 2006; 8:
A) a flame heated endo plugger, B) GatesGlidden drills C) GPX drills
sixty-six extracted maxillary central Removed from CEJ Ah26 Six teeth were used as positive and negative control other sixty teeth were divided into 3 groups, each group containing 20 teeth apical dye leakage in each group was measured by astereomicroscope
Minimal mean dye leakage was related to the hot plugger group Maximum mean leakage was observed in Gates glidden drill group
Kwan and Harrington (1981) and Madison and Zakariasen (1984) found that post space preparation with Gates Glidden drills immediately after obturation actually decreased the amount of apical leakage.
Flame-heated endo pluggers Fast Inexpensive dont cause canal shape alterations Burn potential for the dentist, dental assistant or the patient did not cause any permanent damage to the periodontium
Peeso reamers Very fast Creates parallel walls which provide optimal retention form for the post possiblity of creating root perforation, canal transportation, overenlargement of the canal Only in straight canals
The gates glidden drills are more conservative instruments compared with Peeso reamers drills
GPX match standardized endothontic file sizes # 25 #50. Slight frictional heat which softens the GP before removal Fast and effective The bur does not engage the dentin so canal shape remains unaltered and the frictional heat generated is minimal