脱位再植牙牙髓不同处理方法对比研究

目的 探讨脱位再植牙牙髓治疗的最佳方法。方法 61例67颗再植牙随机分为四组，A组：术前不做牙髓治疗直接再植，出现牙髓病变时常规根充，B组：术前去髓，根充碘仿氢氧化钙，（Metapaste)半年后常规根充，C组；术前去髓，根充氢氧化钙，半年后常规根充，D组；术前去髓常规根充，结果 当牙脱位时间超过30分钟后，术前牙髓治疗组的疗效显著优于术后牙髓治疗组。术前去髓充入根管过渡性药物氢氧化钙或碘仿氢氧化钙组的疗效显著优于即刻常规根管治疗组，单纯使用氢氧化钙与使用Metapaste做根管过渡性药物，二者间疗效无显著性差异。结论 牙脱位时间大于30分钟后，术前去髓，先充入氢氧化钙类根管过渡性药物，半年后行根充糊剂加牙胶尖永久充填为较理想的牙髓治疗方法。     

Periapical tissue reactions to calcium hydroxide and MTA after external root resorption as a sequela of delayed tooth replantation

Clinical experience has shown that most avulsed teeth are replanted after a long extra-alveolar time and dry or inadequate wet storage, causing necrosis of periodontal ligament cells. This condition invariably leads to development of external root resorption, leaving the filling material in contact with the periapical connective tissues. In this study, the periapical tissue reactions to calcium hydroxide (CH) and mineral trioxide aggregate (MTA) were evaluated after occurrence of external root resorption as an expected sequela of delayed tooth replantation. Twenty male Wistar rats (Rattus norvegicus, albinus) had their right upper incisor extracted and maintained in dry storage for 60 min. Then, the dental papilla, enamel organ, pulp tissue, and periodontal ligament were removed, and the teeth were immersed in a 2% acidulated phosphate sodium fluoride solution, pH 5.5, for 10 min. The teeth were randomly assigned into two groups (n = 10), in which the canals were filled with either a CH and saline paste (CH group) or MTA (MTA group). The sockets were irrigated with saline, and the teeth were replanted. After 80 days, it was possible to observe large areas of replacement root resorption and some areas of inflammatory root resorption in both groups. More severe inflammatory tissue reaction was observed in contact with calcium hydroxide compared with the mineral trioxide aggregate. New bone formation was more intense at the bottom of the socket in the MTA group. In conclusion, as far as periapical tissue compatibility is concerned, intracanal MTA can be considered as a viable option for root canal filling in delayed tooth replantation, in which external root resorption is an expected sequela.     

Periodontal response to two intracanal medicaments in replanted monkey incisors

Abstract – Intracanal medicaments are recommended for use in replanted teeth to inhibit inflammatory root resorption. This study compared the effect of calcium hydroxide (Pulpdent^®) and a corticosteroid-antibiotic paste (Ledermix^®) on periodontal healing and root resorption following replantation. Incisors of eight Macaca fascicularis monkeys were extracted, stored dry for 15 min and replanted. After 11 days, root canals in two adjacent maxillary incisors were treated with one medicament and contralateral incisors with the other medicament, or left as untreated controls. Animals were sacrificed 8 weeks later and the teeth prepared for histomorphometric evaluation of periodontal ligament inflammation and root resorption. Periodontal ligament inflammation and inflammatory root resorption were markedly inhibited by both calcium hydroxide and corticosteroid-antibiotic relative to untreated controls. Replacement resorption was lowest in the corticosteroid-antibiotic group, and significantly ( P <0.05) more normal periodontal ligament was present in this group (79.6%) than in calcium hydroxide and control groups (64.6% and 62.7%, respectively). Treatment with the corticosteroid-antibiotic inhibited inflammatory resorption and was slightly more effective than calcium hydroxide in producing a periodontal healing response.     

Zinc oxide-eugenol and calcium hydroxide pulpectomies in baboon primary molars: histological responses.

AIM: To compare histological responses to zinc oxide-eugenol (ZOE) and calcium hydroxide (CH) pulpectomies in primary molar teeth with inflamed pulps. STUDY DESIGN: This was an experimental study in 17 juvenile baboons (Papio ursinus). METHODS: Pulpitis was induced with fresh human carious dentine or Streptococcus mutans placed into occlusal cavities in 78 primary molars; after 14 days a pulpectomy was performed on the same primary molars with the two root fillings randomly allocated. The root canal openings were then covered with IRM and the cavity filled with amalgam. After 90 days specimens were harvested and examined under the light microscope with the examiner blind to the treatment. RESULTS: Reaction frequencies in the ZOE-treated versus CH-treated teeth were: no recognisable pulp 89% and 82%, internal root resorption 0% and 1%, external root resorption 11% and 24%, presence of bacteria 5% and 18%, periapical abscesses 24% and 52%. STATISTICS: Fisher's exact probability test showed a statistically significant higher prevalence of periapical abscesses in the CH-treated group (P=0.03, relative risk 2.2). CONCLUSIONS: ZOE pulpectomy is preferred to CH for the treatment of infected pulps in primary molars.     

Short-term vs long-term calcium hydroxide therapy after immediate tooth replantation: a histomorphometric study in monkey's teeth

Abstract – Endodontic treatment is an important step of tooth replantation protocols, but the ideal moment for definitive obturation of replanted teeth has not yet been established. In this study, a histomorphometric analysis was undertaken to evaluate the repair process on immediate replantation of monkey’s teeth after calcium hydroxide (CH) therapy for 1 and 6 months followed by root canal filling with a CH‐based sealer (Sealapex^®). The maxillary and mandibular lateral incisors of five female Cebus apella monkeys were extracted, kept in sterile saline for 15 min, replanted and splinted with stainless steel orthodontic wire and composite resin for 10 days. In Group I (control), definitive root canal filling was performed before tooth extraction. In Groups II and III, CH therapy started after removal of splint, and definitive root canal filling was performed 1 and 6 months later, respectively. The animals were euthanized 9 months after replantation, and specimens were processed for histomorphometric analysis. In all groups, epithelial attachment occurred at the cementoenamel junction or very close to this region; the areas of resorption on root surface had small extension and depth and were repaired by newly formed cementum; and the periodontal ligament was organized. Statistical analysis of the scores obtained for the histomorphometric parameters did not show any statistically significant difference (P = 0.1221) among the groups. The results suggests that when endodontic treatment is initiated 10 days after immediate replantation and an antibiotic regimen is associated, definitive root canal filling can be performed after a short‐term CH therapy.     

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 effect of intracanal Ledermix on root resorption of delayed-replanted monkey teeth

Abstract – Progressive root resorption is one of the common sequelae in replanted teeth, which is detrimental to their long‐term prognosis. Ledermix paste, with its composition of triamcinolone acetonide and demethylclortetracycline, has been shown to inhibit inflammation and the associated hard tissue resorption. This study evaluated the effect of immediate intracanal Ledermix on root resorption of delayed‐replanted monkey teeth. A total of 36 roots were root canal treated. For the experimental group, intracanal Ledermix was placed prior to extraction and replantation after 1‐h bench dry. The positive control group was root filled and replanted after 1 h while the negative control group was root filled and replanted immediately. The monkeys were sacrificed after 12 weeks. The H&E histological tissue specimens were prepared and evaluated using a method modified from that of Andreasen's morphometric analysis, as favorable or complete healing and unfavorable healing, comprising inflammatory root resorption and replacement resorption. The results were analyzed using Kruskal–Wallis and Mann–Whitney U‐tests as well as Wilcoxon signed ranks test. The negative control group produced highly significant favorable healing and unfavorable healing as compared to the Ledermix group (P = 0.000). The Ledermix group only showed significantly higher occurrence of complete healing (35.46%) compared to the positive control group (16.58%) (P = 0.037) but there were no significant differences in the inflammatory root resorption and replacement resorption. Nevertheless, when the latter two unfavorable healing patterns were combined, there was a significantly lower overall unfavorable healing in the Ledermix group (64.54%) when compared to the positive control group (83.43%) (P = 0.037). This unfavorable healing outcome in the Ledermix group, however, was not significantly different from the favorable healing outcome with the same treatment modality (P = 0.110).     

The risk of healing complications in primary teeth with root fractures: A retrospective cohort study

Background/Aim

Primary teeth are frequently affected by traumatic dental injuries. Root fractures are rare and have a reported incidence of 2% in the primary dentition. Hence, there is limited evidence on this topic. This study aims to evaluate the risk of healing complications in primary teeth with root fracture and to identify possible sequelae in the permanent dentition following root fracture in the primary dentition.

Materials and methods

A retrospective analysis of a cohort of 53 patients with 74 root fractured primary teeth. The standard follow-up program included clinical and radiographic examination after 4 weeks, 8 weeks, 6 months, and 1 year after the trauma and when the patient was 6 years of age. The following complications were registered: pulp necrosis (PN), pulp canal obliteration (PCO), ankylosis with replacement root resorption (ARR), infection-related root resorption (IRR), premature tooth loss (PTL), and repair-related resorption (RRR). Statistics: The Kaplan–Meier and Aalen-Johansen estimators were employed. The level of significance was 5%.

Results

A total of 74 teeth were included. 42 teeth were extracted at the initial examination. Risks estimated after 3 years: PTL 45.9% [95% CI: 28.8–63.0], PCO 12.9% [95% CI: 2.3–23.4], PN 14.9% [95% CI: 3.9–25.9], RRR 2.6% [95% CI: 0.0–7.5]. No teeth showed ARR or IRR. All complications were diagnosed within the first year. Most common sequelae in the permanent dentition was demarcated opacities, with an estimated risk of 20% [95% CI: 8.2–41.3].

Conclusions

There is a low risk of healing complications following a root fracture in the primary dentition. Root fractures often result in early extraction of the coronal fragment. The remaining apical fragment will undergo a physiological resorption. Aside from opacities, there is a low risk of sequelae in the permanent dentition.     

Factors affecting the time of onset of resorption in avulsed and replanted incisor teeth in children

Abstract – Resorption is the main reason for loss of replanted teeth. The outcome examined in this study is the timing of the onset of resorption. The effect of dichotomised dry and wet time intervals as well as the presence of additional crown damage and of contamination were determined. Of 84 replanted teeth, 67.5% developed resorptions. Twenty-eight had detectable additional crown damage with a more rapid onset being seen in these cases ( P =0.009). The critical limit for dry time was 15 min ( P =0.038) and significant differences persisted for greater limits also. Serial analysis of the association between the time of onset of root resorption and dichotomised wet time variables failed to yield any significant associations. There was visible contamination detected in 32 teeth and these exhibited a more rapid onset of resorption than the other cases ( P =0.030). Teeth with inflammatory root resorption (12.8%) had a more rapid onset of resorption than those that developed replacement resorption (54.7%) ( P <0.001). It is concluded that the risk of early resorption is increased in teeth that have additional damage or have contamination, or are kept in dry conditions for longer than 15 min.     

Root surface treatment using diode laser in delayed tooth replantation: radiographic and histomorphometric analyses in rats

Abstract – Background aim: The aim of this study was to evaluate, by radiographic and histomorphometric analyses, the effects of high‐power diode laser irradiation on the root surfaces of delayed replanted rat teeth. Material and methods: Maxillary right incisors were extracted from 60 Wistar rats and kept dry for 60 min. Subsequently, the root canals were prepared and filled with calcium hydroxide paste. According to the root surface treatment before the replantation, the teeth were assigned to four groups (n = 15): G1 (negative control) – no root surface treatment; G2 (positive control) – treated with 2% sodium fluoride solution; G3 – irradiated with a high‐power diode laser (810 nm, continuous mode, 1.0 W, 30 s); and G4 – irradiated with a diode laser using the same parameters as those used for G3 but in pulsed mode. The rats were euthanized after 15, 30, and 60 days of replantation. The specimens were digitally radiographed and processed for histomorphometric analysis to determine the average root resorption areas and to evaluate the histological events. Results: The percentage of root resorption was in the following order: G1 > G2 > G4 > G3. Both histomorphometric and radiographic analyses showed significantly lower means (P < 0.05) of the occurrence of root resorption in the irradiated groups (G3 and G4) when compared to the control groups (G1 and G2). Replacement resorption and ankylosis were observed in histological sections only after 30 and 60 days; however, such events were not observed in G3. Conclusion: Root surface treatments with high‐powered diode laser irradiation prior to delayed replantation reduced the occurrence of external root resorption compared to no treatment or sodium fluoride treatment at up to 60 days.     

Intracanal dressing and root canal filling materials in tooth replantation: a literature review

Abstract – The prognosis of tooth replantation is usually related to the need of endodontic treatment, which has a direct relationship with the occurrence of root resorptions. Several studies have been undertaken in an attempt to prevent, delay, or treat these complications, which are the main causes of loss of replanted teeth. This literature review examines research evidence on intracanal dressings and root canal filling materials used in cases of tooth replantation. A comprehensive search was performed in the Medline/Pubmed, Bireme and Scielo full‐text electronic journal databases to retrieve English‐language articles referring to these topics that had been published between 1964 and 2010. Calcium hydroxide (CH) remains the usually recommended choice as an intracanal medicament in replanted teeth; however, there is evidence to support the initial use of a corticosteroid‐antibiotic combination such as Ledermix paste to control potential early resorption, prior to the introduction of CH where the beneficial effect in the treatment of progressive root resorption has been well proven. Regarding root filling materials, CH‐containing sealers are a good option because of their biological properties. Accurate diagnosis and adequate treatment plan may constitute very complex tasks, particularly in tooth avulsion because several variables are involved. In addition to the technical knowledge and clinical experience directed toward the quality of treatment, patient education may favorably influence the survival of replanted teeth.     

Local dexamethasone improves periodontal healing of replanted dogs' teeth

Abstract— The purpose of the present investigation was to evaluate histologically the effect of dexamethasone on root resorption in stored and replanted dogs' teeth. Twenty-nine roots from three beagle dogs were endodontically treated to prevent subsequent inflammatory root resorption of pulpal origin. The teeth were extracted and randomly assigned to three groups for 18-h storage. Group 1: control group teeth ( n = 13) were stored in vials containing ViaSpan only; Group 2: topical treatment teeth ( n =10) were stored in vials containing ViaSpan and dexamethasone (16 μg/ml); and Group 3: systemic treatment teeth ( n =6) were stored in bids containing ViaSpan without any additives. Dexamethasone was administered intramuscularly (0.5 mg/kg body weight) 2 days prior to, on the day of, and every other day after extraction and replantation for two administrations. After 12 weeks, the dogs were sacrificed, and the teeth histologically prepared and evaluated according to the analysis of Andreasen. Significant differences were found for complete healing ( P= 0.0583) and inflammatory root resorption ( P= 0.0568) but not for replacement resorption ( P= 0.1952). In addition, comparing local to systemic administration of dexamethasone (Group 2 vs. Group 3), statistically significant differences were found for healing, 85% (Group 2) vs. 67% (Group 3) ( P =0.0125) and inflammatory root resorption, 13% (Group 2) vs. 28% (Group 3) ( P =0.0126). This study indicated that topical use of dexamethasone enhances healing and results in fewer resorption complications.     

Results after replantation of avulsed permanent teeth. I. Endodontic considerations

Abstract – Following avulsion and replantation, teeth are at risk for infection and infection related resorption (IRR). Severe discolorations of tooth crowns and cervical root fractures are common. This study presents data on endodontic related complications of avulsed teeth replanted following an extraoral endodontic treatment. Periodontal aspects will be discussed in the second part of the present publication. Twenty‐eight permanent teeth in 24 patients aged seven to 17 years were replanted after avulsion. All teeth could be evaluated. In all teeth extraoral endodontic treatment by retrograde insertion of ceramic or titanium posts was performed. Mean observation period was 31.2 months (median: 24.1 months). Nine teeth healed with a functional peridontal ligament (PDL) (functional healing, FH), 19 teeth exhibited replacement resorption (RR), which was succeeded by IRR in three teeth after observation periods of more than 14 months. Diagnosis was set to tunneling resorption (one case) and to cervical resorption preceded by complete RR (two cases). No early IRR was observed. All six teeth rescued in physiologic conditions (cell culture medium of tooth rescue box) exhibited FH. Discolorations of tooth crowns or other complications (cervical root fractures, fractures of posts) were not observed. No differences in the healing results of immature and mature teeth were observed which is in contrast to previous studies. This finding is explained with the different endodontic treatment protocols. Extraoral endodontic treatment by retrograde insertion of posts prevents early IRR and minimizes the overall incidence of IRR. The method does not negatively influence periodontal healing. As there are further advantages (no discoloration, no root fractures, patient not involved, less radiographs, less time consumption, less costs) the method is recommended in isolated teeth before replantation. Especially immature teeth profit from the prevention of complications.     

Evaluation of various root canal filling materials in primary molar pulpectomies: an in vivo study

PURPOSE: To evaluate the clinical and radiographic success of zinc oxide-eugenol (ZOE), Calcicur, Sealapex and Vitapex in primary molar pulpectomies. METHODS: 80 primary molars, showing signs of pulpal and/or periapical involvement, with no abnormal mobility, were selected from 76 children aged between 4-9 years-old, free from systemic disease. Radiographic evaluation was done to exclude teeth showing internal or pathological external root resorption and/or inadequate bone support. The selected teeth (20 in each group) were randomly treated with ZOE, Sealapex, Calcicur and Vitapex. The procedure involved primarily a one-visit pulpectomy. The teeth were evaluated clinically and radiographically every 2 months for a period of 18 months. RESULTS: In the ZOE group, all pulpectomies were successful. In the Sealapex group, two pulpectomies and in the Calcicur group, four pulpectomies showed complete resorption of the material in the root canal. Although re-treatment was performed, those teeth had to be removed due to pathological root resorption. In the Vitapex group, although six pulpectomies showed resorption of the filling material within the canals, this had no effect on the clinical and radiographical success of the treatment.     

The effects of topical application of bisphosphonates on replanted rat molars

Abstract – The purpose of this study was to evaluate the potential usefulness of two bisphosphonates (BPs) (etidronate and zoledronate), compared with that of alendronate, which is a well‐known drug for delayed replantation, in decreasing or preventing inflammatory root resorption and replacement root resorption in replanted teeth. Eighty‐four Sprague Dawley rat maxillary first molars were extracted, dried for 60 min and then replanted after root treatment. The rats were divided into four groups (control, alendronate, etidronate, zoledronate) as following treatments of avulsed root before replantation. At 7, 14, and 28 days postreplantation, the animals were sacrificed and the samples obtained and process for microscopic analysis. The data were statistically analyzed with the SPSS procedure, anova test and each test was complemented by the Tukey’s post hoc test. The result indicated that topical application of alendronate and zoledronate, both nitrogen containing BPs, prevented inflammatory root resorption and inflammatory cell response in the delayed replantation model. Both drugs were demonstrated similar effects in the delayed tooth replantation model (P = 0.9). Etidronate did not prevent inflammatory root resorption and inflammation in the delayed replantation (P < 0.05). No significant differences in replacement root resorption were observed among all drugs. These results suggest that when teeth are dried and not replanted immediately, zoledronate, like alendronate, may prevent root resorption and facilitates the regeneration of periodontal tissues after replantation.     

Long‐term retention of avulsed maxillary permanent incisors replanted after prolonged non‐physiological storage

Ankylosis and external replacement resorption (ERR) are two typical biological responses to delayed replantation of avulsed teeth in cases where adequate root canal treatment is performed. The patient's growth stage affects the progression of root resorption and the long‐term outcome of the affected teeth. This case report describes the long‐term outcome of an 18.5‐year‐old patient following an accident in which both of his maxillary central incisors were avulsed and replanted after four hours of non‐physiological storage. ERR and ankylosis of teeth 11 and 21 were detected clinically and radiographically during the second year of follow‐up. Sixteen years after replantation, replacement resorption was progressing very slowly, enabling functional tooth retention with favorable esthetics. Young adults, with delayed replantation of avulsed teeth, may benefit from tooth retention with slow ERR.     

Use of hydroxyapatite in tooth replantation radiographically followed up for 14 years: a case report

Abstract –  A lateral incisor was replanted 4 h after trauma. The tooth subsequently developed external root resorption treated with calcium hydroxide initially and with a hydroxyapatite root filling subsequently. Radiographs of the replanted tooth were obtained to follow up the patient for 14 years.     

影响再植牙预后的相关因素分析

目的 分析再植牙根吸收的发生率、发生时间、牙齿在口腔内的保留时间及其影响因素。方法 对1988～2002年在北京大学口腔医院儿童口腔科就诊的59名患儿的68颗延期再植恒牙进行1～15年的临床回顾性分析。结果 再植牙根吸收的发生率为71％；根吸收最常发生在外伤后3～6个月；年龄越大，越早发生根吸收；钙离子导入能延长再植牙在口腔内的保留时间；延期再植牙的脱出时间对其在口腔内的保留时间长短影响较小。结论 延期再植牙经适当的临床治疗，仍可在口腔内保留数年。     

Influence of conventional forceps extraction and extraction with an extrusion instrument on cementoblast loss and external root resorption of replanted monkey incisors

Cementoblast loss and root resorption on the root surface was registered histologically after removal and immediate replantation of maxillary central incisors in monkeys ( Cecropithecus aethiops ). Incisors were removed with either a conventional extraction technique using forceps or with a special designed extrusion instrument and in both cases teeth were immediately replanted. Altogether 18 monkeys were used for the experiments in which 9 monkeys were sacrificed after 3 d and 9 animals after 8 wk. Histological analysis was made in horizontal sections perpendicular to the long axis of the tooth using either 24 measuring points or 12 sections. Histometric analysis showed extensive cementoblast loss in the periodontal ligament (PDL) and with a maximum of damage occurring on the corner surfaces of the root. Extracted teeth showed significantly more extensive cementoblast loss than extruded teeth. Root resorption was also found in the corner locations and was significantly more frequent in extracted than in extruded teeth. There was a similarity in the distribution of cementoblast loss and root resorption indicating that root resorption develops in the same areas where cementoblast loss takes place, i.e. locations that are more compressed during removal of the tooth and must have caused by mechanical damage to the PDL exerted on the root surface during tooth removal.