ABSTRACT
Aims: Management of vertically fractured mandibular first molar by intra coronal splinting applying the finite centre of rotation effect of Pythagorus theorem. Case Presentations: A 28 year old male patient presented at the Department of Conservative Dentistry and Endodontics with the chief complaint of pain in the lower right back region of the mouth since last the 10 days. Past dental history revealed that affected tooth had root canal treatment done two years ago. History of present illness was that pain was elicited on chewing, and applying pressure on that area, with occasional bleeding from the same region. Intraoral examination revealed that tooth 46 was tender on percussion with vertically fractured crown in mesiodistal direction. Periapical Radiograph revealed that tooth was endodontically treated, with radiolucencies at apical and furcal area, and visible fracture line in mesiodistal direction at CEJ level. Technique Used in the Study: The tooth was endodontically retreated and Pythagorus theorem was used to locate the centres of rotation on both buccal and lingual sides of tooth 46 coronally. The technique was followed by drilling a vent at the same position approximating a fibre post (3M, Relyxfibre post). The centres were different both for buccal and lingual aspects which when approximated will provide antirotation. The post was placed in the buccolingual direction and the tooth was restored with posterior composites after which the restoration was checked for any high points. Follow up of the case was done for the period of one year. Discussion: The concept of the estimation of the finite centre of rotation is like the primary objective in tightening a screw joint to generate an optimum preload that will maximize the fatigue life of the screw while offering a reasonable degree of protection against loosening. The major advantage of this approach is that the fragment was stabilized properly and there was healthy development of periodontium over the year. Conclusion: Usually the vertically fractured tooth have poor prognosis and may likely be referred for extraction if not stabilized properly. This case report emphasizes the basic concept of stabilization and preventing rotation around an axis which will give the fractured tooth a better longevity and avoid the vibrations during crown preparation. The combined effect will restore the patient’s own natural tooth back and minimizes the chances of periodontal complication.
ABSTRACT
Objective:To compare the bonding strength of 3M Adper Easy One(3AEO),Clearfil S3 Bond(CSB)and Super-Bond C&B(SBCB)in vertical tooth fracture mode.Methods:30 freshly extracted human molars were randomly assigned to three groups(n =10).The teeth were cut along the long axis with low speed cutting machine and were prepared into a unified model of the vertical tooth fracture.The three adhesives were respectively used to adjoin the surface of the fractured teeth.The samples were subjected to thermal cycling for 500 cycles,stored in distilled water at 37 ℃ for 24 h.Then the pillar-like specimens with the bonding area of 1.0 mm × 1.0 mm were prepared.The microtensile bond strength was measured and the fracture mode was observed.Results:The bond strength (MPa)of 3AEO,CSB and SBCB was 18.57 ±4.98,16.93 ±4.70 and 22.75 ±5.18 respectively(P 0.05).Conclusion:The surface bonding of Super-Bond C&B in tooth fracture is stronger than 3MAdper Easy One and Clearfil S3 Bond.