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At least 1,567 records · Page 87Linked to original sources
PubMed1995

The influence of endodontic infection on progression of marginal bone loss in periodontitis.

The purpose of the present investigation was to determine magnitude and rate of proximal radiographic attachment loss in relation to endodontic infection in periodontally involved teeth. The investigation was conducted as a retrospective longitudinal study on a periodontitis-prone randomly selected referral population, including 175 single-rooted, root-filled teeth in 133 patients. An observation period of at least 3 years was required. Periapical conditions of the selected sample at baseline and re-examination were evaluated on radiographs, independently by 3 investigators. Each single-rooted, root-filled tooth of the sample was given a score according to the combined registrations. Radiographic attachment level was measured as the distance between the most coronal point of the alveolar bone and the apex at the mesial and distal sides of the tooth, and expressed as relative radiographic attachment level (RRAL) (radiographic attachment level at baseline/root length) at proximal sites for every tooth. Multiple regression analysis was used to study change in RRAL over time. Teeth in periodontitis-prone patients with progressing periapical pathology indicating a continuous root canal infection were found to lose comparatively more radiographic attachment than teeth with no signs of periapical pathology or teeth with an established periapical destruction which subsided during the observation period. An approximate 3-fold amplification of the rate of marginal proximal radiographic bone loss by endodontic infection in periodontitis-prone patients was found with an average 0.19 mm/year, while 0.06 mm/year was lost for teeth without endodontic infection or subsiding endodontic involvement.

Adult↗
PubMed2002

Localized alveolar bone necrosis following the use of an arsenical paste: a case report.

AIM: To describe some toxic effects of arsenic trioxide in the mouth, to condemn its continued use, and present a case in which a tooth was preserved despite significant bony destruction. SUMMARY: A case is presented in which severe alveolar bone necrosis resulted from leak-age of an arsenical devitalization paste into the periodontium. The tooth was root canal treated before root amputation, and restored with a cuspal coverage restoration. The tooth was observed to be symptomless and functional at the one-year follow-up. KEY LEARNING POINTS: * Arsenic and its compounds have no place in contemporary endodontics. * Dentists should protect their patients by avoiding the use of arsenic-containing materials and refusing to use products whose constituents are not known. * Localized bone necrosis may not require tooth extraction. Depending on the severity of the case, the tooth may be preserved by a combination of endodontic, periodontal,prosthodontic and maintenance therapies.

Adolescent↗
PubMed1998

Hyalinization and root resorption during early orthodontic tooth movement in adolescents.

The aim of this investigation was to study the hyalinization of the periodontal ligament with time and its relationship to root surface resorption after the application of an orthodontic force, reactivated weekly, of 50 cN (approximately 50 g). Fifty-six patients (18 boys and 38 girls, mean age 13.8 years) were divided into 7 groups of 8. In each patient, one premolar was moved buccally 161 with a fixed orthodontic appliance. The contralateral premolar served as a control. The experimental periods ranged from 1 to 7 weeks. Local areas of overcompression in the periodontal ligament were recorded in 33 test teeth (59%) and 2 controls (4%). Hyalinization was seen in all experimental groups, more often after the first 4 weeks of force application. Hyalinized areas were recorded opposite an intact root surface (54%) or close to and just apical or coronal to an area of root resorption (45%), and were usually located buccocervically and linguoapically, corresponding to expected pressure zones of the periodonal ligament.

Adolescent↗
PubMed2002

[Osteo-odonto-keratoprosthesis. A summary of 6 years surgical experience].

PURPOSE: In patients with severe corneal scarring and vascularisation, corneal grafts have a high risk of failure. In those patients an osteo-odonto-keratoprosthesis (OOKP) can be performed. METHOD: We performed OOKP in eight patients in all with ocular pemphigoid, severe alkali burns, or repulsion of a corneal graft. Each of the patients had finger-counting visual acuity or less. The OOKP consisted of a PMMA cylinder 8 mm long, with a diameter of 3-4 mm, and from a root of the patient's tooth. This was implanted in the cornea and covered with buccal mucosa. RESULTS: The medium follow-up was 3 years. The implants are now well incorporated. The best visual acuity was between 0.6 and 0.9 in four patients with intact retinas. In the remaining patients, visual acuity was dependent on the posterior segment findings. The visual field was centred. Five of the eight patients had vitreous bleeding after the operation that was spontaneously absorbed. Revision of the mucous coverage was necessary in four patients, and one of them had a severe inflammation with partial absorption of the bone and tooth implant. One patient developed a secondary angle-closure glaucoma and was treated successfully by implantation of an Ahmed valve. Two patients developed membranes behind the cylinder that were successfully removed. There was no loss of any prosthesis during follow-up. CONCLUSIONS: In impasse in severe corneal scars, the osteo-odonto-keratoprosthesis is still indicated and shows good results in visual rehabilitation of patients.

Adult↗
PubMed1989

The position of the inferior dental canal and its relation to the mandibular second molar.

Five hundred dental panoramic tomograms of patients over the age of 17 years were examined and any radiographic relationship of the mandibular second molar to the inferior dental canal noted. The position of the inferior dental canal within the mandible was also noted and compared with previous studies. In the population examined, 2% of mandibular second molars were radiographically related to the inferior dental canal and this was 2.5 times more common in women. The importance of the close proximity of the inferior dental nerve to the apex when root filling or extracting this tooth is considered.

Adolescent↗
PubMed2004

C-shaped canal system in mandibular second molars: Part I--Anatomical features.

The purpose of this study was to investigate the anatomical features of C-shaped root canal system in mandibular second molars using micro-computed tomography (microCT). Fifty-eight extracted mandibular second molars with fused roots were collected from a native Chinese population. The teeth were scanned into layers of 0.5-mm thickness by microCT and measurements were made at eleven levels. The ratio of the depth of the deepest part of the groove to the buccal-lingual thickness of the cross-section of the root was calculated for each tooth. The canal shapes of the scanned cross-sections were assessed and classified according to a modified Melton's method. Results were subject to the Kruskal-Wallis test. Of the 58 molars, 54 had a C-shaped canal system with a mean groove-to-thickness ratio of 47.96%; the four teeth without a C-shaped canal had a mean ratio of 14.82%. Most orifices (98.1%) were found within 3 mm below the cementoenamel junction. Of teeth with a C-shape canal system, a majority demonstrated an orifice with an uninterrupted "C" configuration. Seventeen canals divided in the apical portion, most of which did so within 2 mm from the apex. The cross-sectional shape varied drastically along the length of the canal. Teeth with a high groove-to-thickness ratio had at least one section with C1, C2, or C3 configuration. The canal shape in middle and apical thirds of C-shaped canal systems could not be predicted on the basis of the shape at the orifice level. Section 2 of this paper addressed the correlation between the radiographic appearance and these microCT images.

Anatomy, Cross-Sectional↗
PubMed2004

Comparison of mandibular premolars and canines with respect to their resistance to vertical root fracture.

OBJECTIVE: To compare the force required to vertically fracture uninstrumented and instrumented mandibular premolars and canines. METHODS: Two groups of single round-canal mandibular premolars and two groups of single oval-canal mandibular premolars were selected after radiographs indicated an internal long:short diameter of 1 or >2 at a level 5 mm from the apex. In addition, two groups of maxillary and mandibular canines were selected. The root canals of three of these groups (one from each category) were conventionally enlarged using same-sized instruments, while the other three groups were uninstrumented. Each root was mounted in an acrylic resin cylinder, and the force required to cause vertical root fracture (VRF) was measured using an Instron tester. RESULTS: No significant difference in resistance to VRF was found between the round- and oval-canal premolars with (p = 0.9) or without (p = 0.6) instrumentation. The average force required to fracture the uninstrumented premolars and canines was 698 and 566 N, respectively. The average force required to fracture the instrumented premolars and canines was 490 and 554 N, respectively. The force required to fracture the instrumented premolars and canines was 30% (p < 0.05) and 2% (p = 0.9) lower, respectively, than that required to fracture their uninstrumented counterparts. CONCLUSIONS: The instrumented mandibular premolars have a higher risk to fracture than the uninstrumented mandibular premolars.

Bicuspid↗
PubMed1995

In-vitro measurement of apically extruded irrigant in primary molars.

This study investigated the weights of irrigant extruded apically through extracted primary molar teeth. The aim was to compare the weight of canal irrigant (isotonic sodium chloride solution) extruded through the root canal using either a syringe fitted with a 27-gauge needle or an endosonic unit. Root canals were divided randomly into five groups of 15 discrete canals. The area of each apical foramen was recorded prior to the use of the irrigant. For each irrigation technique the maximum depth of penetration of the needle tip/file was either 2-3 mm or 6-7 mm from the apical foramen. In four groups the crowns of the teeth were in a mandibular position, in the fifth group the teeth were inverted to simulate maxillary teeth. The results showed that irrigant was extruded using both methods. There was significantly less extrusion of irrigant when the endosonic unit was used (P<0.01). There was no statistically significant relationship between foramen area and amount of extruded irrigant (P>0.05). There was no significant extrusion of irrigant in teeth with closed apices when either of the two methods was used (P>0.05).

Analysis of Variance↗