Comparison of Fracture Resistance of Endodontically Treated Teeth Restored with Different Aesthetic Post and Core Systems Under All Ceramic Restoration Luted with Two Types of Cements

Context: Fracture of endodontically treated teeth is a grave sequela that a clinician should seriously ponder. Suitable selection of restorative materials is a requisite for long?term clinical success. Aims: To compare the fracture resistance of endodontically treated teeth restored with three different posts luted using two different cements under all ceramic crowns. Settings and Design: This in vitro study was conducted in the Department of Prosthodontics, Government Dental College, Kottayam, Kerala, India. Methods and Material: Thirty endodontically treated single?rooted mandibular premolars in which post spaces were prepared and divided into three different groups. Group 1 (n = 10): zirconia post group. Group 2 (n = 10): quartz fibre post group. Group 3 (n = 10): glass fibre post group. Each group is sub?divided into two based on the luting system: resin?modified glass ionomer cement (RMGIC) or dual?cure resin cement (DCRC). The fracture resistance testing was performed in a universal testing machine with a crosshead speed of 0.5 mm/min. Statistical Analysis Used: The mean fracture resistance were analysed using independent sample Student t?test and one?way ANOVA. Results: Within the zirconia post group, the mean fracture resistance was higher in DCRC sub?group compared to the RMGIC sub?group and the difference was statistically significant (p = 0.017). The difference in fracture resistance between three different post systems was not found to be statistically significant with respect to both the luting systems. Conclusions: It was observed that when zirconia post is used, the mean fracture resistance was higher in dual?cure resin group compared to the resin?modified GIC group.

Reattachment of coronal fragment using fiber reinforced post.

Anterior crown fractures are a common form of injury that mainly affects children and adolescents due to their position in the oral cavity especially in the maxillary arch. Reattachment of original tooth fragment to the fractured tooth forms a relatively quick, biologic and esthetic restoration. A 28 years old male reported to the Department of conservative dentistry & endodontics with a complex crown fracture of 21 and 22 one day after the trauma had occurred. Following endodontic treatment, a glass fibre post was used to increase retention and distribute stresses along the tooth. The dental restoration was completed using the original fragment and a dual cure resin composite. Clinical and radiographic examination at 3, 6 & 11 months recall showed the glass fiber post and restoration was in place, indicating the success of the treatment in maintaining the fractured tooth.

A comparative evaluation of the fracture resistance of endodontically treated teeth with compromised intra radicular tooth structure using three different post system.

Intra-radicular loss of tooth structure in endodontically treated teeth poses a challenge. Available methods for treatment are cast post-core, intra-radicular resin reinforcement using composite resin followed by placement of prefabricated metal/fibre post (glass or carbon).This study is an attempt to investigate the validity of treatment of such teeth using above methods and evaluate which post system is best suited for rehabilitation. Thirtysix endodontically treated anterior teeth were prepared by uniformly removing intra-radicular tooth structure from buccal, lingual, mesial & distal surfaces such that only 0.75mm-1mm remained. Twelve teeth were subsequently restored with cast metal post & core, 12 with intra-radicular resin reinforcement followed by prefabricated titanium post (Luminex post system) & 12 with intra-radicular resin reinforcement followed by glass fibre post (Luscent Anchor post system). Statistical analysis used was t-test. There was no statistically significant difference between the 3 post systems, but it was observed that cast post & cores caused more apical & oblique fractures, rendering the teeth unrestorable. Teeth restored with intra-radicular resin reinforcement & placement of titanium or glass fibre post failed with root fractures limited to the coronal aspect along with dislodgement of post. Intra-radicular resin reinforcement offers advantages like preventing the metal display of the post through the thin dentinal wall, reinforcement of the thin walled teeth & comparable fracture resistance to cast post and core.

Technique to repair iatrogenically-damaged roots during post canal preparation using resin composite and optic fibre posts

During post crown restoration, the preparation of the post canal can be fraught with difficulties resulting in widening, gouging and transportation of the post canal; sometimes with near root perforation. A technique is described to repair such iatrogenically damaged internal root canal walls using reinforcing resin composite and optic glass fibre posts. The root dentine, resin composite and glass fibres, having similar moduli of elasticity, will result in a repaired root with a ‘monolithic’ structure and possessing numerous desirable characteristics. This repair technique can easily be carried out in one sitting at the chairside thereby allowing the continued serviceability of the iatrogenically compromised root-filled tooth.

Health Assessment for Glass Fibre Landfill at Gozan-dong, Inchon / 예방의학회지

In September 1994, residents of Gozan-dong, Incheon City, made a petition to the government about their health problems which might be caused by previous glass fibre landfill nearby "H" company. In February 1995, at regular academic meeting of occupational and environmental medicine, a research team of "D" University presented that they had found glass fibres in groundwater of the area through their survey. They were suspicious of probable association between ingestion of groundwater contaminated with glass fibres and skin tumors among residents. A joint research team was formed and carried out the survey of environment concerning groundwater and its glass fibre existence, and health assessment of residents in the area and industrial workers of "H" company during May to November, 1995. Analysis of groundwater flow system indicates that the flow lines from the glass fibre landfill pass through or terminate at the 6 houses around the landfill. This means that the groundwater of the 6 houses around the glass fibre landfill could be affected by some possible contaminants from the landfill, but the groundwater quality of the other houses was irrelevant to the landfill. The qualitative and quatitative analyses for glass fibres in 54 groundwater samples including those from the nearby 6 houses, were carried out using SEM equipped with EDS, resulting in no evidence for the presence of glass fibres in the waters. Major precipitates, formed in waters while boiling, were identified as calcium carbonates, in particulary, aragonites in needle form. The results of health assessments of 889 residents in Gozan-dong, participated in this study, showed statistically significant differences in past medical histories of skin tumor and respiratory disease between the exposed group (31 persons who inhabited in 6 houses around the landfill) and the control group, but no significant differences in past medical histories of other diseases, such as cancer mortality, current gastroscopic findings, current skin diseases and respiratory diseases, etc. Also, we could not prove any glass fibres in excised specimens of 9 skin tumors in both groups and there were no health problems possibly associated with glass fibres in employees of the "H" company. After all, we could not authenticate the association, raised by prior investigators, between groundwater streams, assumedly contaminated with glass fibres or not, and specific disease morbidities or common disease/symptom prevalences. That is, we could not find any glass fibres in groundwater as the only exposure factor of this study hypothesis, and there were not enough certain evidences such as increasing disease prevalences, for examples, skin, respiratory and gastrointestinal diseases etc, possibly related to glass fibre exposure, in exposed group. As a matter of course, the conditions for confirming causal association, for example, strength of the association, consistency of the association, specificity of the association, temporality of the association and dose-response relationship etc, have not been satisfied. In conclusion, we were not able to certify the hypothesis that contamination of groundwater with glass fibres might cause any hazardous health effects in human who used it for drinking.