Root Furcation

Abstract: The aim of this study was to evaluate the remaining dentine/cementum thickness using Gates-Glidden burs in serial and crown-down sequences and to observe which of the two sequences is the safest for preparing mesial roots of molars. Thirty-six left and right human mandibular first molars were selected. Standard access cavities were made and initially explored with Flexofiles sizes 10 and 15 until the tip was visible at the apex. The teeth were embedded in a muffle specially developed for this study using a PVC tube with two parallel metal rods in its lid. Each tooth-block was sectioned 3 mm apically to the furcation using a low-speed saw with a diamond disc. The tooth-block was examined under a microscope and an initial image was captured by a digital video system with 8 X and 12 X magnifications. Finally, the tooth-blocks were reassembled in the muffle so that the canals could be instrumented. After instrumentation the area of each mesial canal as well as the smallest distance to the root furcation were measured again. The mesio-buccal canals (crown-down order) and the mesio-lingual canals (serial sequence) presented an average area of 0.46 ± 0.16 mm2 and 0.88 ± 0.27 mm2 (P < 0.01), respectively. The mean values of the smallest distance to the furcation for the mesio-buccal and mesio-lingual canals were 0.66 ± 0.19 mm and 0.39 ± 0.13 mm (P < 0.01), respectively. The remaining dentine/cementum thickness using Gates-Glidden burs was greater in the crown-down sequence than in the serial sequence.

Abstract: The objective of the present study was a morphometric and morphologic analysis of maxillary and mandibular first and second molars using three different techniques. Measurements of 207 maxillary molars (105 first and 102 second molars) and 207 mandibular molars (110 first and 97 second molars) were measured; root length, radicular trunk length (RTL), mesiodistal and buccolingual diameters (BLD) at the cementoenamel junction, inter-radicular angle (IRA) width, and furcal roof area (FRA) were recorded. No significant statistical correlations were found for most of these measurements, the only exception being the relationship between IRA/FRA, IRA/BLD in maxillary molars, and IRA/RTL in the maxillary first molar. Morphologic examination was carried out by stereo microscopy, light microscopy of undecalcified sections, and scanning electron microscopy. All of these techniques showed the complexity of the furcation area with a large number of anatomic irregularities and plaque-retentive structures that could hamper adequate cleaning during periodontal treatment.

Abstract: The purpose of this project was to characterize the histopathology of radiolucent furcation lesions associated with primary molars which had received pulpotomy treatment Twenty-four pulpotomy-treated primary molars which displayed radiolucent lesions in the root furcation suggesting unsuccessful outcome were extracted Pretreatment radiographs were available for 6 teeth and none had evidence of a furcation radiolucency These 6 teeth were treated with a standard formocresol pulpotomy and restored The pretreatmen t condition and the pulpotomy procedure employed for the remaining 18 teeth is unknown If a lesion remained attached to the root, it was transferred to 10% neutral buffered formalin The sockets were gently curetted and the tissue transferred to fixative Specimens were processed and stained for microscopic examination Histological examination of the lesions revealed granulomatous, chronic proliferative, and acute inflammation and epithelium Three specimens were diagnosed as furcation granulomas Stratified squamous epithelium was observed in 21 specimens which were diagnosed as either a furcation granuloma with epithelium or a furcation cyst if an epitheliallined lumen was present Pulpotomy-treated primary molars should receive periodic postoperative radiographic examination and be extracted if a furcation lesion develops

Abstract: The aim of this study was to elucidate the relationship between root resorption of the maxillary first deciduous molars and the developmental state of the successive permanent teeth. Twenty-four specimens of the maxilla from 12 dry skulls were classified into four dental eruption stages based upon their deciduous and permanent dentition. Serial sections prepared from the maxilla and embedded in polyester resin were observed with soft X-ray films. The area from the lowest point of the protruded part of the zygomatic process to the alveolar crest of the maxillary first deciduous molar was divided into 6 areas parallel to the Frankfort plane. Specimens from the upper 1/6, 3/6 and 5/6 areas were used. In addition, the shortest distance from the root resorption surface to the bony crypt was measured. The bony crypt containing the successive permanent tooth germ was located closer to the buccal root among the 3 roots of first deciduous molars but grew lingually with the progress of eruption stage. The distance from the root resorption surface to the bony crypt shortened and resorption actively progressed from the deciduous dentition stage to the first molar, and the central incisor reached the occlusal line in the deciduous dentition stage. Three-dimensional reconstruction to reproduce the relationship between the root and bony crypt revealed an increase in the root resorption surface with the eruption phase and growth of the bony crypt in the direction of root furcation.