External Inflammatory Root Resorption Research Articles

Prevalence of different periapical lesions associated with human teeth and their correlation with the presence and extension of apical external root resorption.

The aim of this study was to determine the prevalence of various periapical pathologies and their association with the presence and extent of apical external inflammatory root resorption in human teeth. One hundred and four root apices from extracted teeth with periapical lesions were examined. Semi-serial sections of soft tissue lesions were stained with HE. The lesions were classified as noncystic or cystic, each with different degrees of acute inflammation: 0, 1, 2 and 3, increasing in severity. The root apices were analysed by SEM. External root resorption was classified according to site, as periforaminal or foraminal, and the extension of the resorbed area graded in increasing area as 0, 1, 2 or 3. Cysts accounted for 24.5% of the samples, 84% of which were associated with marked inflammation. The most prevalent diagnosis was noncystic periapical abscess with varying degrees of severity (63.7%). Periapical granuloma was not a frequent finding. SEM analysis showed that 42.2% of the root apices had periforaminal resorption extending over 50% of their circumference. When the foraminal resorption was evaluated, 28.7% had resorption affecting >50% of the periphery. Only 8.9% of the samples showed no periforaminal or foraminal resorption. In the sample of extracted teeth investigated, 24.5% of the periapical lesions were cysts. Most periapical lesions (84.3%) displayed acute inflammation, whether cystic or not. Periforaminal resorption was present in 87.3% of the cases, and foraminal resorption in 83.2%. Periforaminal and foraminal resorptions were independent entities. There was no association between external root resorption and the nature of the periapical lesions.

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.

CERVICAL ROOT RESORPTION

This article describes cervical root resorption, an external inflammatory root resorption arising immediately below the attachment level of the root. The pathogenesis is not fully understood, although many theories have been presented. Clinically, cervical root resorption is usually asymptomatic. The radiographic appearance is variable and is easily mistaken for that of internal root resorption. Histologically, the presentation is identical to that of other inflammatory root resorptions.

Therapeutic delivery of calcitonin to inhibit external inflammatory root resorption. I. Diffusion kinetics of calcitonin through the dental root.

Insertion of calcitonin into root canals of monkey teeth has been shown to inhibit external inflammatory root resorption and suppress inflammation. Regulation of this therapeutic event depends upon the rate of arrival (diffusion) of the hormone at sites of resorptive activity. In the present study, the diffusion characteristics of calcitonin through the dental root in an extracted human-tooth model are described, and the role of cementum in the diffusion process is also addressed. Root-canals were endodontically prepared to form a reservoir for [125I]-calcitonin, and macerated to remove organic material from dentinal tubules. In teeth with intact cementum, an initial period of delay (4-5 h) prior to the detection of calcitonin at the external tooth-root surface was followed by a rapid release of the calcitonin during the first 10.5 h (rate peaks at 6 h). Slower, sustained releases of calcitonin through intact cementum were measured for the following 9 days. Removal of cementum, to expose "smear-free" dentine, resulted in an earlier efflux of calcitonin (2 h) at external tooth surfaces and increased amounts of calcitonin release over 9 days. Biphasic delivery of calcitonin by such internal diffusion mechanisms suggests that loss of cementum will enhance therapeutic availability, while prolonged delivery to intact external dental-root surfaces following early intra-canal placement may also be useful for the therapeutic prevention of external inflammatory root resorption.

Therapeutic delivery of calcitonin to inhibit external inflammatory root resorption. II. Influence of calcitonin binding to root mineral.

Experimentally-induced external inflammatory tooth-root resorption can be inhibited by therapeutic doses of calcitonin. Such doses can be delivered by an intrinsically slow diffusion pathway, from a reservoir in endodontically-debrided root canals, via the dentinal tubules. While the kinetics of this journey have been followed in an earlier report, the binding characteristics of calcitonin to the tooth mineral, which will be responsible, in part, for these kinetics, have not been reported before. The current study examines the binding potential of calcitonin to root mineral and addresses the potential role of non-specific binding proteins. A modified Scatchard plot indicated that a simple non-reactive type of ligand binding exists between calcitonin and root mineral, represented by a small number of identical binding sites. This interaction is both strong and reversible. Furthermore, it appears to be time-dependent with more time being required for the residual ligands to interact with the diminishing numbers of free calcitonin-binding sites. While preloaded [125I]-calcitonin could be incompletely (75-91%) displaced from dental-root material by non-radioactive calcitonin, its release was slow over 23 h. Calcitonin was four times as effective as bovine-serum albumin in competing for common "calcitonin binding sites" on macerated dental-root material. Thus, even in the presence of extraneous protein, calcitonin will bind tightly but reversibly to tooth-root material, making it a good candidate for therapeutically protracted delivery to external root surfaces from root canals.

Treatment of intruded permanent incisors: a multidisciplinary approach

The case presented is a report of a healthy 11-year-old boy, who fell down and traumatized his four maxillary incisors. Both central incisors were deeply intruded with concomitant uncomplicated crown fractures, and both lateral incisors suffered concussion. The intruded teeth were repositioned using a removable orthodontic appliance and were endodontically treated 3 weeks after trauma. Tooth 11 became ankylosed 3 months post trauma, and tooth 21 was extruded to its original position after 5 months. Five months post-trauma, teeth 12 and 22 underwent necrosis and were endodontically treated. In addition, tooth 22 presented an external inflammatory root resorption that was arrested by calcium hydroxide paste after 3 months. A crown-lengthening procedure was performed on tooth 11 10 months post-trauma, exposing the clinical crown to a better condition for restoration. All 4 incisors were restored with a composite material, and the incisal edges of the central incisors were shaped at the same level. Two months after the crown lengthening procedure, spontaneous eruption occurred on tooth 11, that had been ankylosed. The restored incisal edge of tooth 11 was reduced to the same level of tooth 21. The patient is under periodical examination till a definitive orthodontic treatment can be performed.

Treatment of a maxillary canine with external inflammatory root resorption

This case report describes the treatment of a maxllary right canine with external inflammatory root resorption. Full instrumentation and long-term calcium hydroxide treatment were carried out. After 8 months and repeated changes of calcium hydroxide, a swelling developed in the buccal mucosa above the canine. Radiographs indicated that the inflammatory lesion adjacent to the resorption cavity had not healed, possibly because of the presence of anaerobic bacteria extraradicularly and inaccessibility to conventional endodontic therapy. The root canal was then obturated. A full-thickness flap was reflected, the granulation tissue was removed, and the resorption defect was repaired with an amalgam filling. Follow-up examinations indicated that the root resorption was arrested and periradicular repair was evident. This case report describes the treatment of a maxllary right canine with external inflammatory root resorption. Full instrumentation and long-term calcium hydroxide treatment were carried out. After 8 months and repeated changes of calcium hydroxide, a swelling developed in the buccal mucosa above the canine. Radiographs indicated that the inflammatory lesion adjacent to the resorption cavity had not healed, possibly because of the presence of anaerobic bacteria extraradicularly and inaccessibility to conventional endodontic therapy. The root canal was then obturated. A full-thickness flap was reflected, the granulation tissue was removed, and the resorption defect was repaired with an amalgam filling. Follow-up examinations indicated that the root resorption was arrested and periradicular repair was evident.

The effect of an antibiotic/corticosteroid paste on inflammatory root resorption in vivo

Progressive external inflammatory root resorption, a result of persistent inflammation within the periodontal membrane, will cause eventual destruction of the tooth root if the inflammation is not eradicated. This study examined the effects of an antibiotic/corticosteroid paste on experimental inflammatory resorption induced in monkeys in vivo. Histologic evaluation of results with the use of a morphometric technique revealed that the paste eliminated inflammatory root resorption and had no damaging effects upon the periodontal membrane. It was concluded that this antibiotic/corticosteroid combination is an effective medication for use in the treatment of progressive root resorption in traumatically injured teeth.

Rate and predictability of pulp revascularization in therapeutically reimplanted permanent incisors.

Abstract The aim of the present investigation was to study the frequency of pulp revascularization in therapeutically reimplanted incisors as well; is its relationship with the following factors: width of apical foramen, duration of extra‐alveolar lime, storage conditions and postoperative administration of antibiotics. Out of 72 immature teeth (width of apical foramen 1.1–5.0 mm) the pulp was revascularized in 13 (18%), while in 88 mature teeth (width of apical foramen 1.0 mm or less) no revascularization occurred. Among parameters tested statistically in immature teeth, a significantly increased frequency of revascularization (p < 0.05) was only found in teeth reimplanted within 45 minutes after avulsion, when compared with teeth reimplanted after a longer extra‐alveolar time, and in mandibular incisors when compared with maxillary incisors (p < 0.01). All teeth in which revascularization did not occur exhibited a periapical radiolucency and/or external inflammatory root resorption.

Orthodontic external root resorption—Endodontic considerations

External root resorption in posttreatment orthodontic patients, if severe, may jeopardize the retention of the tooth or teeth involved. Numerous studies (1-5) have been undertaken to determine the relationship between the frequency and severity of external root resorption and orthodontic movement. Some investigators found the incidence of root resorption to be low (6-9), while others found it to be much higher (10, 11). The general conclusion is that external root resorption occurs in nearly all patients undergoing the forces that accompany orthodontic treatment. In recent years the use of calcium hydroxide pastes to inhibit inflammatory external root resorption has become an accepted treatment modality. Heithersay (12) and Andreasen (13) have shown that filling the instrumented root canal with calcium hydroxide can inhibit inflammatory resorptive processes. Burke (14) and Cvek (15) described the arrest of external root resorption in permanent incisors by using calcium hydroxide. These investigations suggest that calcium hydroxide has useful application in the management of a range of endodontic problems. This case is of interest because a patient presented with a chief complaint of extreme mobility of the maxillary incisors. Upon examination of sequential periapical radiographs, it was found that external apical root resorption continued after active and retentive orthodontic treatment had been terminated. A method for inhibiting external root resorption and a technique for esthetically splinting anterior teeth are described.

Criteria for diagnosis of pulp necrosis in traumatized permanent incisors.

Records and radiographs of 108 patients (6-18 years) with 134 root canal treated incisors were examined. Subluxation was the most common type of injury, followed by intrusive, extrusive or lingual luxation, exarticulation and uncomplicated crown fracture. Negative response to electric stimulation was noted in 107 teeth from the first examination. In 23 teeth an initial positive response changed to negative within 3 weeks to 9 months, whereas persistent positive reactions were recorded in four teeth. The diagnosis of necrosis was based on the following observations: negative vitality and radiographic changes (76 teeth), negative vitality and discoloration (45 teeth), negative vitality only (nine teeth), positive vitality and radiographic changes (four teeth). External inflammatory root resorption confirmed the diagnosis of necrosis in all replanted teeth and in 13 of 16 intruded teeth. Discoloration and periapical lesions were the most important diagnostic factors following subluxation, extrusive and lingual luxation. Necrosis was disclosed within 4 months in 117 teeth (87%). Diagnoses based on negative vitality and discoloration were made within 6 days to 3 months in all but one case. All external root resorptions and 37 of the 49 periapical lesions were observed within 3 weeks to 4 months of the injury.

Diagnostic procedure for confirmation of a suspected resorptive defect of the root

Three types of external root resorption resulting from luxation injuries of the periodontal structures and the pulp have been described as follows1: ---Surface resorption. Superficial resorption lacunae develop on the root surface, possibly as a response to a localized injury to the periodontal ligament or cementum. This type of resorption is thought to be self-limiting and can show spontaneous repair. -Replacement resorption. Progressive root resorption and disappearance of the periodontal space are seen radiographieally. Histologically, a direct union between bone and root is seen (ankylosis), with the tooth substance being gradually replaced by bone. Inf lammatory resorption. Resorption of the root with adjacent bone destruction is seen radiographically. Microscopic examination shows lacunaeshaped areas of resorption of dentin and cementum with inflammation of the adjacent periodontal tissue. Treatment of external root resorption has been studied extensively, especially inflammatory root resorption~-5; however, little attention has been given to its clinical diagnosis, apart from routine radiographic findings. The latter may be sufficient in the majority of cases, but there are occasional situations in which it is imperative to establish a firm diagnosis in the absence of definitive radiographic findings. The following case illustrates the need for a confirmatory diagnostic procedure when the radiographic findings are only suggestive of external inflammatory root resorption.