Effect of immediate calcium hydroxide treatment and permanent root-filling on periodontal healing in contaminated replanted teeth

Abstract – The effect of immediate permanent root-filling and immediate intracanal calcium hydroxide treatment on experimentally contaminated and necrotized periodontal membranes (PDM) in avulsed and subsequently replanted monkey teeth was studied. Almost the entire root surface in the non-endodontically treated control teeth were covered with inflammatory resorp-tion, A significant shift towards ankylosis not associated with root resorption (> 80% of the total root surface area) was noted following calcium hydroxide treatment. About two thirds of the root surfaces from the teeth with permanent root fillings showed surface resorptions or ankylosis preceded by root resorption. The root surface area which would have been covered by inffammatory resorption, unless endodontic treatment had been implemented, were instead predominantly covered by either surface resorption (permanent root filling) or ankylosis (calcium hydroxide treatment), Ankylosis compared with surface resorption may in the long term lead to progressive loss of root substance due to replacement resorption. It was concluded that calcium hydroxide may be an excellent initial intracanal treatment in teeth with healthy PDM, but care should be taken not to risk unnecessary development of ankylosis by prolonged treatment of teeth with compromised PDM.     

Effect of delayed calcium hydroxide treatment on periodontal healing in contaminated replanted teeth

Abstract – The effect of delayed intracanal calcium hydroxide treatment on experimentally induced extensive inflammatory root resorption in monkeys was studied. A significant shift from inflammatory resorption to ankylosis was noted following calcium hydroxide treatment. Furthermore, calcium hydroxide treatment appeared to change the pattern of ankylosis over time, although the total ankylotic area remained the same. Ankylosis preceded by root resorption (replacement resorption) increased, while ankylosis not associated with root resorption decreased. It was concluded that intracanal calcium hydroxide treatment of teeth with compromised PDM may cause unnecessary replacement resorption if left in the root canal for a long time or changed repeatedly.     

Effect of delayed calcium hydroxide treatment on periodontal healing in contaminated replanted teeth

The effect of delayed intracanal calcium hydroxide treatment on experimentally induced extensive inflammatory root resorption in monkeys was studied. A significant shift from inflammatory resorption to ankylosis was noted following calcium hydroxide treatment. Furthermore, calcium hydroxide treatment appeared to change the pattern of ankylosis over time, although the total ankylotic area remained the same. Ankylosis preceded by root resorption (replacement resorption) increased, while ankylosis not associated with root resorption decreased. It was concluded that intracanal calcium hydroxide treatment of teeth with compromised PDM may cause unnecessary replacement resorption if left in the root canal for a long time or changed repeatedly.     

Effects of intracanal medicaments on inflammatory resorption or occurrence of ankylosis in mature traumatized teeth: a review

Abstract A review of the literature of the effect of intracanal medicaments on inflammatory resorption or occurrence of ankylosis in mature traumatized teeth is presented. The results of the studies show that calcium hydroxide and Ledermix paste eliminate inflammatory resorption. Other medicaments such as gutta-percha with sealer, antibiotics, and calcitonin reduce or almost eliminate this complication. Ankylosis or replacement resorption develops in the root surfaces of teeth with mature roots irrespective of medicaments used. However, the percentage of relative surface area of the root which develops ankylosis is significantly higher in mature teeth treated with calcium hydroxide than in teeth treated with permanent root filling. Ledermix paste targets the resorbing cells without damaging neighbouring tissue. Recommendations for the use of calcium hydroxide and Ledermix paste as intracanal dressings in traumatized mature teeth are made.     

Intracanal bisphosphonate does not inhibit replacement resorption associated with delayed replantation of monkey incisors

Abstract – Progressive replacement resorption following delayed replantation of avulsed teeth has proved to be an intractable clinical problem. A wide variety of therapeutic approaches have failed to result in the predictable arrest of resorption, with a good long‐term prognosis for tooth survival. Bisphosphonates are used in the medical management of a range of bone disorders and topically applied bisphosphonate has been reported to inhibit root resorption in dogs. This study evaluated the effectiveness of a bisphosphonate (etidronate disodium) as an intracanal medicament in the root canals of avulsed monkey teeth, placed before replantation after 1 h of extraoral dry storage. Incisors of six Macaca fascicularis monkeys were extracted and stored dry for 1 h. Teeth were then replanted after canal contamination with dental plaque (negative control) or after root canal debridement and placement of etidronate sealed in the canal space. A positive control of calcium hydroxide placed 8–9 days after replantation was also included. All monkeys were sacrificed 8 weeks later and block sections were prepared for histomorphometric assessment of root resorption and periodontal ligament status. Untreated teeth showed the greatest extent of root resorption (46% of the root surface), which was predominantly inflammatory in nature. Calcium hydroxide treated teeth showed the lowest overall level of resorption (<30% of the root surface), while the bisphosphonate‐treated group was intermediate (39%). Ankylosis, defined as the extent of the root surface demonstrating direct bony union to both intact and resorbed root surface, was the lowest in the untreated control group (15% of the root surface), intermediate in the calcium hydroxide group (27%) and the highest in the bisphosphonate group (41%). Bony attachment to the tooth root was divided approximately equally between attachment to intact cementum and to previously resorbed dentin. Overall, bisphosphonate resulted in a worse outcome than calcium hydroxide in terms of both root resorption and ankylosis.     

Prognosis of luxated non-vital maxillary incisors treated with calcium hydroxide and filled with gutta-percha. A retrospective clinical study.

A material of 885 luxated, non-vital incisors was evaluated radiographically with respect to healing of periodontal tissues including inflammatory root resorption and occurrence of ankylosis and cervical root fractures. The results were assessed after completion of calcium hydroxide treatment and 4 years after filling of the root canal with gutta-percha. After treatment with calcium hydroxide, periapical healing occurred in 95% of the teeth. Four years after filling with gutta-percha, periapical healing was present in 91% of the teeth. In the remaining teeth, recurrent or persistent periapical radiolucency was more frequent in overfilled than adequately filled teeth (P = 0.0001). There was no difference between immature and mature teeth. Inflammatory root resorption healed in 192 of 197 teeth (97%); in 5 teeth it developed into ankylosis. Ankylosis occurred in 13 teeth, all of which were intruded into the alveolar bone at the time of injury. The frequency of cervical root fractures was markedly higher in immature than mature teeth (P greater than 0.0001). Among immature teeth, the frequency of fractures was dependent on the stage of root development (chi 2 = 31.6) and ranged from 77% in teeth with the least to 28% in teeth with the most developed roots. The frequency of fractures was also related to the defects after healing of inflammatory root resorption in the cervical area of the root, significant at P less than 0.0001.     

Prognosis of luxated non-vital maxillary incisors treated with calcium hydroxide and filled with gutta-percha. A retrospective clinical study

Abstract A material of 885 luxated, non-vital incisors was evaluated radiographically with respect to healing of periodontal tissues including inflammatory root resorption and occurrence of ankylosis and cervical root fractures. The results were assessed after completion of calcium hydroxide treatment and 4 years after filling of the root canal with gutta-percha. After treatment with calcium hydroxide, periapical healing occurred in 95% of the teeth. Four years after filling with gutta-percha, periapical healing was present in 91% of the teeth. In the remaining teeth, recurrent or persistent periapical radiolucency was more frequent in overfilled than adequately filled teeth (P = 0.0001). There was no difference between immature and mature teeth. Inflammatory root resorption healed in 192 of 197 teeth (97%); in 5 teeth it developed into ankylosis. Ankylosis occurred in 13 teeth, all of which were intruded into the alveolar bone at the time of injury. The frequency of cervical root fractures was markedly higher in immature than mature teeth (P>0.0001). Among immature teeth, the frequency of fractures was dependent on the stage of root development [x²= 31,6) and ranged from 77% in teeth with the least to 28% in teeth with the most developed roots. The frequency of fractures was also related to the defects after healing of inflammatory root resorption in the cervical area of the root, significant at P< 0.0001.     

Use of vitamin C in delayed tooth replantation

This study evaluated microscopically the effects of root surface treatment with three different solutions in delayed rat teeth replantation. Central incisors from 30 rats (Rattus norvegicus, albinus Wistar) were extracted and left on a bench for 6 h. The pulps were extirpated and root canals were irrigated with 1% sodium hypochlorite. After endodontic treatment, the root surfaces of all teeth were submitted to a 10-min treatment with 1% sodium hypochlorite, changed every 5 min. The teeth were then rinsed with saline for 10 min and assigned to 3 groups with ten specimens each. Groups I, II and III were treated, respectively, with 2% acidulated-phosphate sodium fluoride, vitamin C solution and effervescent vitamin C (2 g, Redoxon. After root surface treatment, the teeth were filled with calcium hydroxide and replanted. The animals were sacrificed after 10 and 60 days. Group I (fluoride) presented the largest areas of replacement resorption and ankylosis. Comparing both vitamin C groups, Group III (effervescent vitamin C) yielded better results, showing more areas of ankylosis and replacement resorption than areas of inflammatory resorption.     

Delayed replantation of avulsed mature teeth with calcium hydroxide treatment

Three avulsed teeth that were replanted and splinted after approximately a 200-min dry extraoral period in two patients are presented. In case 1 calcium hydroxide treatment was performed 1 month after replantation, because the patient did not come for endodontic treatment on the day after replantation as requested. In case 2, calcium hydroxide treatment was initiated on the day after replantation. Calcium hydroxide treatment was used to prevent or treat inflammatory root resorption. During the follow-up periods the teeth reported in these cases have remained in a stable, functional position and did not reveal clinical ankylosis or replacement resorption.     

Effect of calcium hydroxide treatment on periodontal repair and root resorption

Abstract Pulpal application of calcium hydroxide is a common treatment for external root resorption. Several mechanisms of action have been suggested. In the present investigation, the effect of pulpal calcium hydroxide on cells at the root surface and in the periodontal ligament was studied by means of scanning-electron microscopy and light microscopy. Lateral incisors in monkeys were extracted, a groove was made- in the root surface and the teeth were then immediately replanted. The pulps of some teeth were infected by bacteria from the saliva. Application of calcium hydroxide in the root canal caused a limited necrosis of the cells resorbing dentin as well as the cells forming reparative cementum in the experimental groove. In the non-infected teeth, a temporary ankylosis developed. The high pH having a bactericidal and necrotizing effect seemed to be sufficient to explain the therapeutic effect of calcium hydroxide on root resorption.     

Morphometric and microscopic evaluation of the effect of a solution of alendronate as an intracanal therapeutic agent in rat teeth submitted to late reimplantation

Abstract –  The use of substances that inhibit root resorption may be an alternative for cases of unsuccessful reimplants. Hence, the purpose of this study was to test a solution of alendronate, a resorption inhibitor, as an intracanal therapeutic agent for teeth submitted to late reimplantation. Thirty rat maxillary right central incisors were avulsed and kept dry for 30 min. The teeth were instrumented, and the root surfaces treated with 1% hypochlorite solution followed by application of 2% sodium fluoride. Thereafter, the teeth were divided in two groups according to the intracanal dressing: (i) group I, solution of alendronate and (ii) group II, calcium hydroxide paste. Teeth were then reimplanted in their respective sockets. The animals were killed at 15, 30 and 60 days after reimplantation and the samples processed for morphometric and microscopic analysis. The results demonstrated that the solution of alendronate and the calcium hydroxide paste limited the root resorption, yet did not impair its occurrence. It may be concluded that alendronate and calcium hydroxide paste demonstrated similar behavior.     

The effect of extra-alveolar root filling with calcium hydroxide on periodontal healing after replantation of permanent incisors in monkeys

The effect of calcium hydroxide, used as an extra-alveolar root filling material, on periodontal healing was examined in green vervet monkeys (Cercopithecus aethiopa). Incisors were extracted and a root canal filling of calcium hydroxide paste was processed. Control teeth were replanted after either pulp extirpation or root filling with gutta-percha. In the experimental groups, the extra-alveolar period was either 18 or 120 minutes. The animals were killed eight weeks after replantation, and the replanted teeth were examined histologically. The histologic parameters recorded for each tooth were surface resorption, inflammatory resorption, replacement resorption (ankylosis), periapical inflammatory changes, and downgrowth of pocket epithelium. Teeth with canals filled with calcium hydroxide that had an extra-alveolar time period of 18 minutes, showed noticeably more replacement resorption than either the teeth with canals filled with gutta-percha or those with extirpated pulps. Calcium hydroxide paste may diffuse through the apical foramen, thus injuring the periodontal ligament in the apical region. Consequently, the use of calcium hydroxide does not seem justified in the initial treatment of avulsed teeth, but it can be used after some weeks when periodontal ligament healing has progressed.     

The role of endodontics in the treatment of luxated permanent teeth

Abstract  – 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.     

年轻恒牙完全脱位再植后疗效分析

目的：评价年轻恒牙完全脱位再植后的愈合方式,对不同发育阶段年轻恒牙再植术后的疗效进行总结,为更好保留患牙的美观与功能提供参考。方法回顾分析30颗完全脱位年轻恒前牙,根据国际牙外伤协会治疗指南进行治疗。评价再植后年轻恒牙牙周组织愈合方式,分为牙周膜愈合、表面吸收愈合、替代性吸收（骨粘连）、炎性吸收。结果30颗完全脱位的年轻恒牙再植后,其中7颗为牙周膜愈合,占23.3%;1颗为表面吸收愈合,占3.3％;13颗为替代性吸收,占43.3%;9颗为炎性吸收,占30.0％。结论年轻恒牙发生完全脱位,再植后愈合方式受多种因素影响。当出现不良的愈合方式限制颌面部发育时,一定要及时干预,减少患者生理和心理的创伤。     

Morphometric and microscopic evaluation of the effect of solution of acetazolamide as an intracanal therapeutic agent in late reimplanted rat teeth

Abstract –  The use of substances that inhibit root resorption may be an alternative for cases of unsuccessful reimplants. Hence, the purpose of this study was to test a solution of acetazolamide, a resorption inhibitor, as an intracanal therapeutic agent for late reimplanted teeth. Thirty rat maxillary right central incisors were avulsed and kept dry for 30 min. The teeth were instrumented, and the root surfaces treated with 1% hypochlorite solution followed by application of 2% sodium fluoride. Thereafter, the teeth were divided into two groups according to the intracanal dressing: Group I, solution of acetazolamide and Group II, calcium hydroxide paste. Teeth were then reimplanted in their respective sockets. The animals were killed at 15, 30, and 60 days after reimplantation and the samples processed for morphometric and microscopic analysis. The results showed that calcium hydroxide paste limited root resorption, even though not avoiding it. In contrast, no root resorption was observed after 60 days in the acetazolamide group, confirming the efficacy of the substance in inhibiting root resorption.     

Short vs. long-term calcium hydroxide treatment of established inflammatory root resorption in replanted dog teeth

Abstract This study examined, histologically, the healing of intentionally produced inflammatory root resorption of replanted teeth in beagle dogs, treated with short- or long-term placement of calcium hydroxide. Thirty beagle dog incisors were randomly divided into four groups. In group 1 (negative control), uninfected incisors were extracted, the roots were longitudinally grooved and the teeth were replanted within 2 min. In group 2 the root canals were artificially infected followed by extraction, longitudinal grooving, and replantation as in group 1. Radiographs were taken biweekly and at the first signs of inflammatory root resorption or at 4 weeks, the root canals were fully instrumented and medicated with calcium hydroxide. In group 2, the root canals were permanently obturated with gutta-percha and sealer after 1 week of calcium hydroxide. The teeth in group 3 were treated as described in group 2 but after 1 wk the calcium hydroxide dressing was repacked for the duration of the study. In group 4 (positive control) the teeth were treated as described in groups 2 and 3 but no endodontic treatment was performed. Twrelve weeks after the initiation of the endodontic treatment, sacrifice and histological preparation were carried out. In group 1, complete cemental repair was seen in all teeth. In group 2, five often teeth showed complete cemental repair whereas in group 3 complete cemental repair was seen in nine of ten teeth. None of the teeth in group 4 showed cemental repair. It was concluded that long-term may be more effective than short-term calcium hydroxide treatment of established inflammatory root resorption.     

Mineral trioxide aggregate as an alternative treatment for intruded permanent teeth with root resorption and incomplete apex formation

Abstract – A case of extensive crown fracture associated with intrusion of the permanent maxillary central incisors in an 8‐year‐old boy is reported. The treatment of both injured teeth included attempts of apexification and arrest of root resorption with calcium hydroxide. After 8 months of the trauma, there was no calcified barrier formation in the apex. Mineral trioxide aggregate (MTA) was then used as a filling material. At 15‐month follow up, the teeth were asymptomatic and correctly sealed, the external inflammatory root resorption had stopped, and the radiolucent image had disappeared, which meant the initial healing of the periapical lesion. MTA may be considered as an alternative option for the treatment of traumatized and immature permanent teeth.     

Evaluation of the anti‐resorptive ability of an experimental acetazolamide paste for the treatment of late replanted teeth: a study in rats

Abstract – When late replantation is performed, the root surface and root canal should be treated. Notwithstanding failures still occur, because of the high rates of root resorption, evidencing the need to search for substances that may inhibit root resorption. The acetazolamide is a known anti‐resorptive agent, and its use as root canal dressing may increase the success rates in the treatment of root resorption. Therefore, this study evaluated the effect of an acetazolamide paste used as root canal dressing in late replanted teeth. The study was conducted on 24 maxillary right incisors of rats, which were avulsed and divided in two groups. In group I, the teeth were kept dry for 30 min, had their root surfaces rubbed with a blade, and were treated with 2% sodium fluoride at pH 5.5 for 20 min; the root canals were instrumented and filled with acetazolamide paste; and then the teeth were replanted. In group II, the treatment was similar to group I, except for the root canal dressing, with utilization of calcium hydroxide in group II. At 15 and 60 days after replantation, the animals were killed and the specimens were processed in a histotechnical laboratory for microscopic and morphometric analysis. The results demonstrated the ability of both intracanal substances to limit root resorption, yet they were unable to completely inhibit the root resorption. Replacement resorption lacunae were present in greater proportion in group II, at 60 days. It was concluded that the acetazolamide paste was effective to limit the root resorption, being more effective in limiting the replacement resorption compared with calcium hydroxide.     

Intrusive luxation of permanent incisors in Norwegians aged 6–17 years: a retrospective study of treatment and outcome

Abstract – Background/Aim: External replacement resorption (ankylosis‐related) is a severe complication leading eventually to tooth loss. Little information exists regarding the influence of variables such as degree of intrusion or treatment method on the development of replacement resolution in intruded permanent incisors. The aim of this study was to report the most frequently involved age group, the preferred type of treatment, and the type and frequency of healing complications. Special attention was paid to the effect of treatment on the occurrence of replacement resorption. Material and Methods: Fifty‐one intruded permanent incisors were studied in 20 boys and 19 girls aged 6 to 17 years. Only three patients were over 12 years of age. Complete intrusion had occurred in 21 teeth, and 31 teeth were classified as immature. Re‐eruption was awaited for 37 teeth. The remaining teeth were repositioned orthodontically (7 teeth) or surgically (7 teeth). Results: Re‐eruption occurred in 35 out of 37 teeth over a period of 3–12 months. After a mean observation period of 4 years ranging from 1–12 years, retained pulp vitality was recorded in 22 teeth (43%). Pulp necrosis had developed in 57%, inflammatory resorption in 26% and replacement resorption in 12%. Whereas all inflammatory resorptions were arrested after long‐term calcium hydroxide treatment, replacement resorption always led to complete root resorption. In the analysis all orthodontic and surgical repositioned teeth were combined into an active treatment group. The non‐active treatment group consisted of teeth allowed to re‐erupt. The distribution of replacement resorption was significantly lower in teeth allowed to re‐erupt than in teeth repositioned actively. Conclusions: The best treatment of intruded incisors in 6–12 year‐old children is to await re‐eruption. Should endodontic treatment be required before re‐eruption has occurred, a gingivectomy can be performed to gain access to the root canal.     

Dynamics of dentoalveolar ankylosis and associated root resorption

The present experimental studies in monkeys were undertaken to study the initiation and progression of dentoalveolar ankylosis of replanted teeth and associated root resorption. Maxillary and mandibular lateral incisors were extracted and replanted after an extraoral period of 15 min or 1 h. Teeth with an extraoral period of 1 h were endodontically treated. Half the number of monkeys were given antibiotics at the time of replantation. The observation periods varied from 2 days to 40 weeks. Irrespective of the length of the extraoral period, initial root resorption and minor areas of ankylosis were found 1 week after replantation. The initial ankylosis was not preceded by root resorption. In teeth replanted after an extraoral period of 15 min the ankylotic area did not increase with increasing time after replantation. Instead the periodontal membrane was re-established, separating the root surface from the alveolar bone. In teeth replanted after an extraoral period of 1 h, the initial ankylotic area increased with increasing time after replantation. Eight weeks and more after replantation, most of the periodontal membrane was replaced by bone covered by osteoblasts and occasional osteoblasts that were in continuity with the endosteal cells outlining the marrow spaces of the alveolar bone. The cementum and dentin were then gradually resorbed with increasing time after replantation. Antibiotics given at the time of replantation reduced the initial inflammation in the periodontal membrane and the inflammatory root resorption after all observation periods and it also seemed to some extent to prevent bacteria from entering the necrotic pulp tissue. Based on the present results it is suggested that root resorption associated with dentoalveolar ankylosis is initiated by endosteal osteoblasts and is thus a hormonally regulated process. This is in contrast to inflammatory root resorption, which seems to be triggered by inflammatory cells.