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An interesting case is reported, of calcification of the dental papilla. As yet, little is known about this asymptomatic calcification, which constitutes a rare radiographic finding, deforming the root of a vital tooth, generally a lower premolar or canine.
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The aim of this study was to compare the effects on root resorption of continuous and discontinuous force application. The experimental material consisted of 22 first premolars that were to be extracted as part of orthodontic treatment. Prior to extraction, a 100 g tipping force was applied to the experimental teeth by means of elastics. One side was randomly selected to be the continuous force side, and the contralateral side became the discontinuous force side. Elastics were worn 24 hours per day on the continuous force side and 12 hours per day on the discontinuous side. The experimental procedure lasted 9 weeks. Composite electron micrographs of the buccal surface of each specimen were digitized and areas affected by resorption were determined. The degree of root blunting was assessed by visual scoring. Mean percentage of resorption-affected areas was smaller and apical blunting was less severe on the discontinuous force side. The results of this study show that the application of discontinuous force results in less root resorption than does the application of continuous force.
This paper is a report on 25 autotransplantations of third molars with complete root formations. The study consists of 23 patients in whom 25 third molars were transplanted. The mean age was 29.6 years (range 20-54). In nine cases third molars were directly transplanted into the new socket. In 11 cases the sockets were widened and made deeper with a bur. In five cases the recipient beds were made by splitting osteotomy of the alveolar region. The transplanted third molars were stabilized with silk sutures, resin, wire splint or circumferential wiring for 1-6 weeks. Two-three weeks after transplantation, the root canals were treated and filled. After operation, the marginal and the periapical conditions were examined clinically and radiographically. The transplanted teeth clinically appeared to become firmer with the passage of time. Progressive root resorption was not found and good results were obtained. This study shows that autotransplantation of third molars with complete root formation produces an acceptable result using the procedures outlined.
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The aim of the investigation was to evaluate the effect of a treatment pause on teeth in which apical root resorption was discovered after an initial treatment period of 6 months with fixed appliance. Forty patients with initial apical root resorption in 62 upper incisors were included in the study. In 20 patients treatment continued according to the original plan and in 20 patients active treatment was interrupted during a pause of 2-3 months. After the pause active treatment was resumed. Assessment of apical root resorption was performed on standardized radiographs taken with individual film holders. The amount of root resorption was significantly less in patients treated with a pause than in those treated without interruption.
The present study focuses on orthodontically provoked, excessive root resorption. The purpose was to identify in these cases common morphological features in radiographic diagnostic material taken before treatment. The material was submitted by 35 Danish orthodontists. The goal was to improve the future orthodontic diagnostics of the dentition in order to prevent severe root resorption during treatment. The study indicates that: (1) there is a strong connection between various dental morphological characteristics, such as invagination, length of root, and root shapes, especially taurodontism, and the tendency to root resorption during orthodontic treatment; (2) there is a connection between anomalies in the dentition, particularly ectopia and agenesis, and the tendency to root resorption during orthodontic treatment; (3) there seems to be a connection between the pattern of resorption in the primary dentition and the tendency to root resorption in the permanent dentition following orthodontic treatment; (4) girls are more susceptible to root resorption during orthodontic treatment than boys; (5) one ought to be on the lookout for connections between condylar changes, root resorptions, and anterior open bites in connection with orthodontic treatment. The observation regarding root resorption in dentitions in which invaginations and taurodontic root shapes occur has not previously been reported. Also, the findings of deviant resorption patterns in both the primary and permanent dentitions in a considerable number of patients are new observations, which ought to be incorporated into orthodontic treatment planning.
The aims of this study were to develop a three-dimensional (3D) mathematical model of a typical root resorption crater and to correlate two-dimensional (2D) surface area measurements to 3D volumetric measurements of root resorption craters created under light and heavy orthodontic forces. Data were obtained from a previous study of 36 first premolars from 16 subjects requiring extraction of these teeth as part of their orthodontic treatment. Buccal tipping forces of 25 or 225 g were applied for an experimental period of 28 days. After extraction, the samples were prepared for scanning electron microscopy (SEM) imaging, image processing and analysis. Surface area (2D) and volumetric (3D) measurements of all craters were obtained. A mathematical analysis of the 2D/3D relationship enabled the determination of an appropriate digital model for the shape, type and dimensions of resorption craters, which was also able to distinguish between a 'hemispheric' model versus a 'layered' model of craters. The results demonstrated that 2D and 3D measurements were strongly correlated (r = 0.991**). Within the light and heavy force groups, the measurements were also strongly correlated (r = 0.978** and r = 0.994**, respectively). For a 28 day experimental period, 2D measurements of root resorption craters were found to be as reliable as 3D measurements.
A case is presented in which a previous partial root canal treatment on a mandibular molar developed internal resorption of the distal canal. The case was followed at the University of Oklahoma student clinic and endodontic treatment completed in the mesial canals, with calcium hydroxide placed in the distal canal for 10 months due to a pre-existing perforating defect of the root surface. Endodontics was then completed. A 17-month follow-up film showed osseous repair apically and also adjacent to the distal root surface where a slight overextension of filling material was evident.
An in vivo investigation is described and a histological evaluation made of the effect of canal obturation by thermomechanical compaction of gutta-percha and sealer on the cementum on the lateral surface of the root and adjacent periodontal membrane and alveolar bone of the ferret canine after time intervals of 24 hours, 20 days and 40 days. These tissue reactions were compared with those in the roots of control teeth filled by lateral condensation of cold gutta-percha and sealer. Iatrogenic damage was apparent in a minority of the experimental specimens 20 and 40 days after obturation.
This study examined the effect of various zinc oxide materials as root-end fillings of teeth in a replantation model. A total of 35 molar teeth were used from 19 monkeys. After extraction, root ends were resected, the canals contaminated with oral bacteria, root-end cavities prepared and fillings placed prior to replantation. After 8 weeks the teeth and surrounding jaw were removed and prepared for histological examination. Twelve roots were filled with IRM plus dentine chips, and six with Cavit; the tissue response around root ends filled with these materials as assessed by inflammation was similar to that previous reported to IRM and Super EBA cement and was characterized by little or no inflammation of limited extent. In contrast, more severe inflammation was observed around root ends filled with plain zinc oxide-eugenol or Kalzinol; however, the reaction was neither as severe nor as extensive as that to amalgam root-end fillings. Giant cells were observed most often on the surface of fillings with Cavit and zinc oxide-eugenol. It is concluded that the tissue response to IRM with or without added dentine, Super EBA and Cavit was similar and mild; it was less severe than that to zinc oxide-eugenol and Kalzinol. All these materials had a much more favourable response than amalgam
Three cases are described illustrating problems of root resorption related to orthodontic treatment. In the first case the short roots of many of the teeth made it inappropriate to carry out orthodontic treatment. In the second case there were no signs of root resorption initially, but, following retraction of maxillary incisors with a removable appliance, root resorption was noted affecting molar and premolar teeth, but not the maxillary incisors. In the third case several teeth had short roots, and further shortening of roots occurred during fixed appliance therapy. These cases illustrate the unpredictable nature of root resorption.
The present study was undertaken to examine whether (1) the process of resorption, which invariably affects periodontitis involved reimplanted roots facing bone or gingival connective tissue during healing, is a transient phenomenon and, (2) root resorption can be prevented by permitting downgrowth of epithelium along the root surface. A total of 24 teeth in 2 monkeys (Macaca cynomolgus) was subjected to experimental periodontal tissue breakdown by the placement of elastic ligatures around the teeth. The ligatures were left in situ until about 50% of the supporting tissues had been lost. Following removal of the ligatures, the teeth were extracted and the denuded portions of the roots were scaled and planed. The crowns of the teeth were resected and the root canals filled with guttapercha. The roots were subsequently implanted into sockets prepared in the jaw bone in such a way that each root was embedded in bone except for a portion which was in contact with gingival connective tissue. 1 month prior to sacrifice of the animals, the cut surface of the coronal part of the roots was exposed by removal of the covering soft tissue. The epithelium was thereby allowed to migrate into the wound. Implantation of the roots was scheduled to provide healing periods of 1, 2, 3, 4, 8, 12, 16, 20 and 24 weeks before exposure of the roots. The histologic examination of the implant specimens disclosed that replacement resorption was a progressive process which eventually resulted in the elimination of the transplanted roots. It was possible to prevent root resorption in this model by permitting apical downgrowth of epithelium along the root surface during the initial phase of healing. The results are discussed in relation to procedures used in periodontal therapy.
Cellular colonization of denuded root surfaces on replanted teeth was examined with scanning electron microscopy. The dentin surface was rapidly colonized by a few macrophage-like cells which resorbed dentin in limited areas. They had well-developed ruffled borders but no clear zones. The resorptive activity was gradually inhibited by the ingrowth of a monolayer of fibroblast-like cells from the periphery of the denuded area. At the advancing front, the ingrowing fibroblast-like cells were long and slender, with long tail-like projections trailing the nuclear domain. The invading cells behind these were well-spread and tightly packed. They had a granulated surface and showed morphological signs of fibre synthesis. After 6 weeks, the entire cavity was covered by a monolayer of these cells. Removal of the cells with sodium hypochlorite revealed that a cementum-like tissue had been formed under the invading cells, indicating that they were cementoblasts. It was concluded that wound repair on the root surface is dependent upon the differentiation and proliferation of pre-cementoblasts in the periphery of the wound and that cells in the main body of the periodontal membrane are of little significance in the healing process on the root surface.
The purpose of this study was to evaluate the effect of furcation entrance width on the efficacy of calculus removal from furcation areas as well as to compare this efficacy between external and furcation surfaces after closed root planing, open root planing and use of a rotary diamond for the furcation area. 30 first and second lower molars scheduled for extraction with a calculus index > or = 2 and a degree II or III furcation involvement were divided into 3 groups: 10 molars were scaled and root planed using a closed approach: 10 molars were scaled and root planed using an open approach; 10 molars were scaled and root planed with an open approach and rotary diamond was used for removal of deposits in the furcation area. After extraction, the width of the furcation entrance was measured buccally and lingually 2 mm apical from the bifurcation and furcations were categorized as wide (width > 2.4 mm) or narrow (width < 2.4 mm). The teeth were assessed in a stereomicroscope and the % of residual calculus on external and furcation surfaces was calculated. The width of the furcation entrance influenced the efficacy in root planning in the open group (p = 0.0015). The use of rotary diamond was the most effective method for removing calculus both for narrow and wide furcations. The effectiveness of open root planning in the mesial root was related to the width of the furcation entrance where the % of residual calculus was significantly higher for narrow furcations (p = 0.008).(ABSTRACT TRUNCATED AT 250 WORDS)
It has recently been shown that administration of the drug 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) perturbs the homeostasis in the periodontal ligament resulting in an osteoid-mediated ankylosis between the alveolar wall and the root surface. In the present study, the events after discontinuing HEBP administration were investigated and the effect of function on repair of the periodontal ligament was evaluated. In mice, the maxillary left molars were extracted. They then received a daily subcutaneous injection of HEBP (10 mg P/kg b.w.) for a period of 50 days, were killed 24 h, 14, 28, 56 and 112 days after the last injection and their mandibles processed for light microscopy. HEBP administration caused a significant decrease of the width of the periodontal ligament space with localized ankylosis. In the period after discontinuing HEBP treatment, the newly-formed bone did first mineralize and was then partly resorbed resulting in the disappearance of the ankylotic areas. Furthermore, root resorption was seen. Finally, the periodontal ligament regained its normal architecture and width and a new layer of cementum was formed. Functional teeth showed more root resorption than hypofunctional ones and a more rapid repair of the periodontal ligament. It is concluded that in the period after HEBP treatment the periodontal ligament regains its normal width by a repair process including extensive root resorption, that seems to accelerate this process.