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At least 955 records · Page 53Linked to original sources

PubMed2003

Maturogenesis: is it a new concept?

The treatment of an undeveloped (immature) tooth with a carious exposure has been reported extensively in the literature. The main objective of treatment is to provide vital pulp therapy to allow continued development of root dentin in the hope that the root will attain full maturity. A case report is presented that illustrates root development (maturogenesis), not just closure of the apex (apexogenesis). A direct pulp cap was performed after a carious pulp exposure using calcium hydroxide with iodoform paste. The crown was restored with a glass ionomer/composite resin cement.

Calcium Hydroxide↗

PubMed1991

[The extraction of a completely impacted upper second deciduous molar: case report].

A 7-year old boy visited the dental hospital complaining that the upper left second deciduous molar had not erupted. Radiographs showed that the crown of this tooth existed near the apex of the upper left first molar. Inversion of the second deciduous molar and second premolar was definite. There were no differences in location, size and shape between the left and right second premolars. A tooth-like object was observed near by the germ of the left second premolar. The impacted molar was examined histopathologically after extraction and consequently it was found that it was a supernumerary tooth. New radiographs were made which suggested that the succedaneous premolar developed normally. The tooth germ of the primolar develops on the lingual side of the deciduous molar and moves in the level of the occlusal plane of the primary molar. Later they are found between the divergent roots and, at the end of the pre-eruptive phase, below the roots of the primary molars. We concluded that the supernumerary tooth disturbed this adjustment.

Child↗

PubMed2003

A nonlinear finite element analysis of the periodontal ligament under orthodontic tooth loading.

The stressed state of the periodontal ligament (PDL) is understood to play a critical role in the tooth movement initiated by orthodontic treatment. Finite element simulations have been used to describe PDL stresses for orthodontic loading; however, these models have predominantly assumed linear mechanical properties for the PDL. The present study sought to determine the importance of using nonlinear mechanical properties and nonuniform geometric data in computer predictions of periodontal ligament stresses and tooth movements. A 2-dimensional plane-strain finite element model of a mandibular premolar was constructed based on anatomic data of transverse sections of tooth, PDL, and bone from a 24-year-old cadaveric man. A second model was constructed of the same tooth but with a PDL of uniform thickness. Each of these was prescribed linear or nonlinear elastic mechanical properties, as obtained in our own experiments. Predictions of the maximum and minimum principal stresses and von Mises stresses in the PDL were determined for extrusive and tipping forces. The results indicated that biofidelic finite element models predicted substantially different stresses in the PDL for extrusive loading than did the uniform thickness model, suggesting that incorporation of the hourglass shape of the PDL is warranted. In addition, incorporation of nonlinear mechanical properties for the PDL resulted in dramatic increases in the stresses at the apex and cervical margin as compared with the linear models.

Adult↗

PubMed2002

The role of endodontics in the treatment of luxated permanent teeth.

Pulp necrosis is a common complication following traumatic dental injuries and is related to the type and severity of the injury, as well as to the stage of development of the injured tooth. Endodontic intervention is required when there are clinical and radiographic signs of pulpal infection and its sequelae. Arrested tooth development with periradicular pathosis, external inflammatory root resorption, sinus tract formation and pain on percussion are indicative of root-canal infection in the post-traumatized teeth, and require immediate endodontic treatment. The use of calcium hydroxide in the treatment of teeth with post-traumatic pulp necrosis and its sequelae has been shown to be extremely beneficial for the long-term retention of the injured teeth. Calcium hydroxide has been shown to arrest and repair external inflammatory root resorptive defects, eliminate the endodontopathic microorganisms from the root canal system and induce hard-tissue barrier formation at the apex of non-vital immature teeth. This paper reviews the endodontic treatment required by post-traumatic non-vital permanent teeth.

Calcium Hydroxide↗

PubMed2001

Retrospective evaluation of the influence of the interleukin-1 genotype on radiographic bone levels in treated periodontal patients over 10 years.

BACKGROUND: A difference in genetic susceptibility to plaque accumulation has been advocated to explain different responses to periodontal therapy. The purpose of this study is to assess the role of the interleukin-1 (IL-1) polymorphism on the rate of bone and tooth loss in non-smoking periodontally treated patients during maintenance. METHODS: Sixty consecutive non-smoking patients (mean age 46.8 +/- 5.0) with moderate to severe periodontitis, treated and maintained for over 10 years were selected. At baseline (T0), radiographic evaluation (cemento-enamel junction [CEJ]-root apex, CEJ-bottom of defect mesial and distal, CEJ-bone crest mesial and distal, crown-root ratio) was performed. All patients received scaling and root planing; 36 patients then underwent surgical therapy. Subsequently, all patients were enrolled in a periodontal maintenance program with recall visits every 3.4 +/- 1.0 months for at least 10 years. At the latest recall visit (T2) the same radiographic measurements evaluated at baseline were taken and a DNA sample for IL-1 genetic susceptibility testing was collected and sent for analysis. RESULTS: Twenty-three of the 60 patients (38.3%) were IL-1 genotype positive. A total of 52 teeth (3.3%) out of 1,566 were lost due to periodontitis between T0 and T2; 28 of 957 (2.9%) in the IL-1 genotype negative group and 24 of 609 (3.9%) in IL-1 genotype positive group. The mean variation in bone defect level (DeltaBD) averaged -0.04 mm in IL-1 genotype negative patients and 0.01 mm in IL-1 genotype positive patients. The mean variation in bone crest level (DeltaBC) averaged -0.24 mm in IL-1 genotype negative patients and -0.28 mm in IL-1 genotype positive patients. However, a few patients showed significant differences in response to therapy based on initial bone levels and genotype. IL-1 negative patients who showed minimal initial bone loss responded to the therapy better than the IL-1 positive patients. IL-1 positive patients with severe initial bone loss showed a better response to the therapy than IL-1 negative patients. CONCLUSIONS: On average, there were no significant differences related to IL-1 genotype in tooth loss after 10 years in a non-smoking, well-maintained periodontal population. On an individual patient basis, the IL-1 genotype, in combination with the initial bone level, seems useful at the beginning of therapy for predicting bone level variation.

Adult↗

PubMed2000

Heat transfer to the periodontal ligament during root obturation procedures using an in vitro model.

It appears to be important to avoid thermal injury to the periodontal ligament when using heated guttapercha techniques such as "System B." An in vitro model was developed, consisting of an extracted human tooth rooted in an artificial periodontal ligament (PDL) and alveolar socket, which allowed us to measure the temperature transferred to the root surface. The teeth were instrumented and subsequently embedded in alginate to simulate the PDL. Medium gutta-percha points were fit, sealer was applied, and a fine Buchanan plugger was used for condensation. Temperature measurements were taken simultaneously at the apex and 5 mm from the apex during obturation with two fine gauge thermocouples connected to a digital thermometer. The average temperature increase was approximately 1 degree C at the apex and approximately 2 degrees C at the 5 mm mark. The resulting temperature increases appear to be lower than previously reported by other investigators (Hardie, 1986, 1987; Barkhordar et al., 1990; Weller et al., 1991; Lee et al., 1998), who did not allow for the heat disseminating effect of the PDL.

Alginates↗

PubMed2002

The relationship between apical root resorption and orthodontic tooth movement in growing subjects.

OBJECTIVE: To investigate the relationship between apical root resorption and orthodontic tooth movement in growing subjects. METHODS: 58 growing subjects were collected randomly into the study sample and another 40 non-treated cases were used as control. The apical resoption of the upper central incisors was measured on periapical film and the incisor displacement was measured on lateral cephalogram. Using multiple linear regression analysis to examine the relationship between root resoption and the displacement of the upper incisor apex in each of four direction (retraction, advancement, intrusion and extrusion). RESULTS: The statistically significant negative association were found between resorption and both intrusion (P < 0.001) and extrusion (P < 0.05), but no significant association was found between resorption and both retraction and advancement. The regression analysis implied an average of 2.29 mm resorption in the absence of apical displacement. CONCLUSIONS: The likelihood that the magnitude of displacement of the incisor root is positively associated with root resoption in the population of treated growing subjects is very small.

Humans↗

PubMed2005

Anterior tooth morphology and its effect on torque.

This study was undertaken to determine the variation in crown-root angle (CRA) of the upper incisors and canines as well as the variation in their labial contour. In addition, the influence of the variability of the labial contour and of different bracket heights on torque was evaluated. Proximal radiographs were taken of 160 extracted maxillary teeth (81 incisors and 79 canines). They were digitized and analysed with Jasc Paint Shop Pro 7TM and Mathcad 2001 Professional. The incisal edge, the centre of the cemento-enamel junction (CEJ), and the root apex were digitized to define the crown and root long axis. For all teeth the CRA was measured. At several heights of the labial surface a tangent was determined, enabling measurement of the inclination of the labial surface. The CRA had great variability, ranging from 167 to 195 degrees for the canines (mean value 183 degrees) and from 171 to 195 degrees for the incisors (average 184 degrees). The mean inclinations of the labial surfaces for the incisors varied greatly. Between 4 and 4.5 mm from the incisal edge the standard deviations (SD) were the smallest and between 2 and 4.5 mm from the incisal edge the labial surface angle differed by approximately 10 degrees. For the canines the mean inclinations of the buccal surface also varied. This angle differed by around 10 degrees between 2 and 4.5 mm from the incisal edge, but the SD were much larger than for the incisors. It can be concluded that placement of a bracket on a tooth at varying heights, still within a clinically acceptable range, results in important differences in the amount of root torque.

Cuspid↗

PubMed1999

Longitudinal post-eruptive mandibular tooth movements of males and females.

Unbiased estimates of post-eruptive eruption and migration of the mandibular teeth for large representative samples are presently unavailable. The purpose of this study was to evaluate pure tooth movements of untreated children and adolescents longitudinally. Lateral cephalograms of 214 French-Canadians, followed bi-annually between 8 and 15 years of age, were traced, and the positions of the mandibular permanent central incisors and first molars were digitized. Temporal changes in tooth position were evaluated relative to naturally stable mandibular reference structures, using the mandibular reference line for orientation. The statistical analyses included t-tests to assess gender differences and Pearson product-moment correlations to evaluate associations. The results showed that the incisors proclined significantly more for males (6 degrees) than females (3 degrees). The incisor tips displayed early mesial movements that were countered by later distal movements. The incisor apex showed a consistent pattern of distal migration between 8 and 15 years. Mandibular arch length decreased over the 7-year observation period. Rates of mesial molar migration accelerated until 11 years of age and then decelerated. There was no significant change in the mandibular occlusal plane angle between 8 and 15 years of age. Incisor eruption showed the greatest rates during adolescence, attaining peaks at approximately 12 years for females and 14 years for males. The molars erupted approximately 5 mm between 8 and 15 years of age. The greatest gender differences occurred at the older ages, with males showing greater eruption potential than females. It was concluded that the mandibular teeth show significant migration and eruption during childhood and adolescence, with gender differences in the amount, direction, and timing of movement.

Adolescent↗

PubMed2006

Traumatic intrusion of permanent teeth. Part 2. A clinical study of the effect of preinjury and injury factors, such as sex, age, stage of root development, tooth location, and extent of injury including number of intruded teeth on 140 intruded permanent teeth.

A prospective study of 140 intruded permanent teeth was done to evaluate the following healing complications: pulp necrosis (PN), root resorption (surface, inflammatory and replacement resorption) (RR) and defects in marginal periodontal healing (MA). These complications were related to various preinjury and injury factors. Age appeared to be related to all three healing complications in that patients younger than 12 years had the lowest complication rate. Stage of root formation at the time of the injury was very strongly related to PN and MA, with immature root formation (i.e. incomplete root formation or completed root formation with wide open apex) having better prognosis than more mature root development. Lateral incisors showed significantly more defects in MA, a finding possibly explained by the observation that lateral incisors were more often involved in multiple intrusions compared to other teeth and noting that multiple intrusions had a significantly higher frequency of MA. An associated crown fracture with exposed dentin resulted in more frequent PN, a finding possibly related to bacterial invasion through dentinal tubules into an ischemic pulp. The presence of a gingival laceration added to both PN and MA. The extent of intrusion (in mm) showed some relation to both RR with intrusion 1-3 mm having the lowest frequency of RR, whereas PN and MA showed no significant relation to the extent of intrusion. Finally, multiple adjacent intruded teeth were more frequently involved in a significantly greater loss of interproximal marginal bone (MA) than single intrusions. In conclusion, the relationship between healing complications and preinjury and injury factors could generally be explained by better healing possibilities in teeth with immature root formation. A possible explanation for that could be the softer bone surrounding the tooth, whereby trauma to the periodontium might be diminished.

Adolescent↗

PubMed1988

Management of an avulsed tooth with severe root resorption.

Delayed replantation of an avulsed tooth with an open apex resulted in failure of revascularization, necrosis of the pulp and extensive external root resorption. Removal of the necrotic pulp and repeated intra-canal dressings of calcium hydroxide over a three year period arrested the inflammatory resorptive process. The process was replaced by replacement resorption leading to ankylosis and infra-occlusion of the affected tooth. As the tooth was asymptomatic, it was retained in the arch to act as a space maintainer. To improve aesthetics, the crown was recontoured using a light-cured resin.

Calcium Hydroxide↗

PubMed1977

Influence of different endodontic methods of treatment upon the process of apical closure of immature pulpless human teeth and the structure of the newly formed calcified tissue in apical opening.

A description is given of the pathohistological structure of the calcified tissue in the apical opening of four extracted immature pulpless human teeth treated by various endodontic methods. It is concluded that in the tooth treated by mortal extirpation there was neither histological healing nor any tendency for further apex formation. In both the tooth where vital extirpation was performed and in one of the teeth treated as apical periodontitis, the apices were formed from conglomerates of different calcified tissues, identical to the tissue which was formed under comparable conditions in experimental dogs. In the fourth human tooth also treated as apical periodontitis after treatment the apical opening closed with irregular dentine tissue. In this study consideration was given to the problem of the origin of the odontoblasts which co-exist with the hard destructive process present in some pulpless teeth. It is concluded that in the case presented in this study the irregular dentine was formed by the same odontoblasts which took part in the process of normal odontogenesis. This fact, should be respected in the course of endodontic treatment of immature pulpless teeth.

Animals↗

PubMed1995

Clinical management of the avulsed tooth.

Treatment outside the dental office: Replant immediately after gentle washing if practical. If replantation is not practical, store the tooth in the best medium available. Storage media in order of preference are Hank's Balanced Salt Solution (HBSS), milk, saline, and saliva (buccal vestibule). Water is the least desirable storage medium. Treatment in the office: Emergency visit; Place tooth in HBSS while exam is conducted and history is taken. Prepare socket for gentle repositioning of the tooth. Prepare the root. Extraoral dry time < 20 minutes: Closed apex--replant immediately after gentle washing. Open apex--soak in 1 mg doxycycline in 20 mg saline for 5 minutes. Extraoral dry time 20 to 60 minutes: Soak in HBSS for 30 minutes and replant. Extraoral dry time > 60 minutes: soak in citric acid, 2% stannous fluoride, and doxycycline and replant. Endodontics can be done extraorally. Semirigid splint for 7 to 10 days. (If alveolar fracture is present, rigid splint for 4 to 8 weeks). Suture soft-tissue lacerations, particularly in the cervical area. Administer systemic antibiotics (penicillin V potassium if possible) Chlorhexidine rinses and stringent oral hygiene while the splint is in place (7 to 10 days). Analgesics as required. Second visit after 7 to 10 days: Endodontic treatment: Tooth with open apex and extraoral dry time of < 60 minutes: No endodontic treatment initially. Recall every 3 to 4 weeks to examine for evidence of pathosis. If pathosis is noted, disinfect the pulp space and start apexification procedure. Tooth with open apex and extraoral dry time > 60 minutes: If endodontics was not completed in the emergency visit, start endodontics and follow apexification procedure. Tooth with closed apex: Endodontics should be initiated after 7 to 10 days. Careful chemomechanical instrumentation under strict asepsis. Splint removed at end of visit. Obturation visit: If endodontics was initiated 7 to 10 days after the avulsion, obturation can take place after short-term calcium hydroxide treatment. If endodontics was initiated more than 14 days after the avulsion or inflammatory resorption, long-term calcium hydroxide for 6 to 24 months, obturated when an intact lamina dura is traced. Restorations: Temporary restorations: Should be 4 mm deep. Reinforced zinc-oxide-eugenol, acid-etch composite resin, glass-ionomer cement. Permanent restoration: Placed immediately after obturation. Acid-etch resin and dentin bonding agents. Follow-up care: Twice per year for 3 years and yearly for as long as possible. Late complications are common.

Dental Restoration, Permanent↗

PubMed2006

Effects of root morphology on stress distribution at the root apex.

It is thought that the stress concentration at the root apex caused by orthodontic force induces root resorption. The purpose of this study was to investigate stress distribution at the root in cases of deviated root shapes using finite element models (FEMs). To clarify this, five three-dimensional FEMs divided by deviated root shape (normal, short, blunt, bent root apex, pipette shape) were constructed and, experimental orthodontic forces, applied in a vertical (intrusive) and horizontal (lingual) direction to the tooth axis. In the short-root model, significant stress was concentrated at the middle of the root. The blunt-shaped root model showed no significant stress concentration at the root. In the models with a bent or pipette-shaped root, significant stress was concentrated at the root apex. During orthodontic force application, stress concentration was observed in the root of the models with short, bent, and pipette-shaped roots, indicating that attention must be paid to root shape during orthodontic treatment.

Alveolar Process↗

PubMed1998

[Injuries to the permanent teeth. Periodontal lesions].

Tooth luxations are relatively common. In case of concussion or subluxation the tooth is not displaced. The treatment will consist of relief of the tooth. Most frequent complications are pulp necrosis and obliteration of pulpal tissues. In case of extrusive luxation pulpal tissues and the periodontal ligament are injured. When tooth mobility is increased flexible splinting should be considered. Endodontic treatment is necessary after extrusive luxation of a tooth with completed root formation. Teeth with open apex often show pulpal obliteration after extensive luxation. Lateral luxation is more complex than extrusive luxation since the alveolar bone is also damaged. Repositioning and splinting of the tooth are necessary. When the apical foramen in closed, endodontic treatment will be necessary. Teeth with incomplete root formation will develop pulp obliteration. Following lateral luxation, external root resorption and loss of marginal bone are not infrequent. Intrusive luxation is the type of trauma with most unfavorable prognosis. All intruded teeth will become necrotic and external root resorption and marginal bone loss are frequent. There is no consensus regarding the therapeutic approach. Orthodontic extrusion or surgical mobilisation are possible options. In case of avulsion, both the pulpal tissues and the periodontal ligament are disrupted. Preservation of the vitality of the periodontal ligament covering the root will determine the prognosis of the reimplanted tooth. Therefore the tooth will be repositioned as soon as possible. When this is not possible, milk or a specific solution are most appropriate for tooth conservation. When the reimplanted tooth has complete root formation, devitalization will be performed one week after after repositioning. In case of a tooth with open apex revascularisation can be awaited. Healing of the periodontal ligament will determine prognosis. When a normal ligament is obtained during healing or when surface resorption is obtained, the tooth can be preserved for a long period. When progressive replacement resorption (ankylosis) develops, most teeth can remain in position for about 10 years. When inflammatory resorption develops, the tooth will be lost within a short time.

Dental Pulp Calcification↗

PubMed2004

Periapical repair and apical closure of a pulpless tooth using calcium hydroxide--a case report.

A case with a open apex and a large periapical lesion in a 10 year old boy is presented. The lesion formed as a result of necrosis from trauma to a maxillary right central incisor 1 year ago. Apical closure and complete healing of periapical lesion was observed after non-surgical endodontic treatment using calcium hydroxide paste. This report suggests that even large periapical lesions could respond favourably to non-surgical treatment.

Calcium Hydroxide↗

PubMed1995

Application of Ca-beta-glycerophosphate for artificial apical barrier formation.

This case demonstrates an artificial apical barrier formation by using calcium-beta-glycerophosphate paste in a nonvital permanent tooth with an open apex communicating with the maxillary sinus. The long-term satisfactory outcome of this case depended on the resolution of periapical pathosis and root canal obturation without overextension.

Adult↗

PubMed2003

The effect of using an inverted master cone in a lateral compaction technique on the density of the gutta-percha fill.

OBJECTIVE: We sought to measure and calculate the percentage of the gutta-percha-filled area in the apical root canal after the use of a standardized or inverted master cone in cold lateral compaction.Study design Two groups of extracted mandibular premolars with a single canal were instrumented with instruments of the same size; furthermore, they were obturated with laterally compacted gutta-percha cones with AH26 used as a sealer. In the first group, a standardized master cone was used with its narrow end in an apical position, whereas in the other group, an inverted master cone was used with its wide end in an apical position. The 2 master cones had the same apical diameter and fit in the apical canal. After lateral compaction, horizontal sections were cut at a level 3 and 5 mm from the apex of each filled tooth. Photographs of the sections were taken by using a microscope equipped with a digital camera; the photos were then scanned as tagged-image file format images. The cross-sectional area of the canal and the gutta-percha were measured by using an image-analysis program. The percentage of gutta-percha-filled area was calculated. RESULTS: At both levels, the inverted master cone produced a significantly higher percentage, statistically, of gutta-percha-filled area than did the standardized master cone (P =.001 at 3 mm; P =.012 at 5 mm). CONCLUSION: The use of an inverted master cone in cold lateral compaction may facilitate the apical placement of accessory cones, significantly increasing the volume of gutta-percha while reducing the volume of sealer in the apical root canal.

Bismuth↗