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.     

Effect of lyophilized autologous plasma on periodontal healing of replanted teeth

The purpose of this histologic and autoradiographic study of replanted teeth was to evaluate the beneficial effect, if any, of lyophilized autologous plasma (LAP) application on periodontal healing and to re-examine rates of repair in different areas of the associated periodontium following replantation. Maxillary and mandibular incisors and premolars of three rhesus monkeys were used. Teeth were extracted with forceps and placed in sterile physiologic saline. After 5 minutes each tooth was returned to its socket and immobilized by interproximal acid-etch splints. Splints were removed after 1 week. Of the 48 replants performed, 24 (controls) were replanted as described. Of the 24 experimental teeth, during the 5 minute interval between tooth extraction and replantation, the root surface and the inner socket walls were bathed with 1 ml of the reconstituted LAP-saline solution (800 mg/ml). Replants and animal sacrifice were scheduled to provide observations at 1, 3, 7, 14, 28 and 45 days following replantation. One hour prior to sacrifice, each monkey received an intravenous injection of tritiated thymidine, 1 microCi/gm body weight. Tissue specimens were processed for evaluation following standard procedures. Eight replanted teeth were available for evaluation for each of the six time-points. Four teeth were treated with LAP and four without it. Histologically, tissue sections were examined for epithelial proliferation and attachment, periodontal fibers organization and maturation, inflammatory cell types, presence or absence of cementum resorption and dentoalveolar ankylosis and degree of vascularity of the tissues. For autoradiographic evaluation, the periodontium associated with the replanted tooth was divided into nine spatial cell compartments. In each compartment, labeled tissue cells, epithelial or connective, were counted and recorded. Differences between the control (untreated) replanted teeth and the LAP-treated teeth, at each time-point and within each compartment, were analyzed for significance using the paired t-test. The findings of this study indicate that LAP use enhanced healing by early replacement of the fibrin clot, increased connective tissue cell proliferation, reduction of the inflammatory response and inhibition of root cementum resorption. Periodontal healing and repair occurred more rapidly in the supracrestal or transseptal connective tissue region than within the periodontal membrane space.     

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.     

Endodontic infection and calcium hydroxide-treatment. Effects on periodontal healing in mature and immature replanted monkey teeth

Abstract Large experimental defects with marginal communication, and small isolated experimental defects were created on the root surfaces of extracted monkey lateral incisors with either open or closed apices. The pulp tissue was either infected or removed, and calcium hydroxide placed in the root canal. The teeth were then replanted and the healing pattern evaluated histomorphometrically after 20 weeks. From the results, it was concluded that (1) an intrapulpal infection promotes marginal epithelial down-growth on a denuded dentin surface irrespective of tooth developmental stage, and that (2) the periodontal healing potential after calcium hydroxide-treatment appears to be higher in teeth with open apices compared with teeth with closed apices, where ankylosis was promoted as opposed to teeth with open apices where significantly more reparative cementum was found.     

The effect of Emdogain gel on periodontal healing in replanted monkeys' teeth

OBJECTIVE: We sought to histologically evaluate the effect of Emdogain gel on periodontal healing in monkeys' teeth undergoing delayed replantation.Study design Mature monkey teeth simulating avulsion were endodontically treated before extraction. Negative control teeth (group N = 10 roots) underwent immediate replantation, whereas the rest were bench-dried for 1 hour and treated in one of the following ways before replantation: the positive control teeth (group P = 12 roots) had no further treatment; group C teeth (4 roots) had the periodontal ligament removed; group D teeth (10 roots) were treated with Emdogain gel; group E teeth (6 roots) had the periodontal ligament removed before the application of Emdogain gel; and group F teeth (7 roots) had the periodontal ligament removed, the root surface conditioned, and Emdogain gel applied. Periodontal healing was evaluated after 16 weeks by undertaking histomorphometric analysis. RESULTS: The Kruskal-Wallis and Mann-Whitney U tests revealed that group N teeth had a statistically higher occurrence of complete healing than did all other groups, whereas group P was not significantly different in any of the healing categories from D, E, and F, the groups in which Emdogain gel was used. Group C teeth had a significantly higher occurrence of replacement root resorption than did the teeth in groups P and F-but were not significantly different from teeth in groups D and E. CONCLUSION: Emdogain gel did not appear to significantly reduce replacement resorption in monkeys' teeth that had undergone delayed replantation.     

Timing of calcium hydroxide therapy in the treatment of root resorption in replanted teeth in dogs

Abstract The effect of time of the onset of calcium hydroxide (CH) pulpectomy on root resorption of 31 permanent dog incisors was investigated. CH pulpectomy was delayed 4, 9, 14 and 18 days after the teeth were extracted and replanted. Control teeth were replanted 1) without pulpectomy, 2) with a pulpectomy only or 31. with a pulpectomy and CH filling. All teeth were prepared for histologic evaluation 8 weeks after the teeth were replanted. Cross section were examined using a computer microscope and linear (jam) and/or square areas (μm²) of surface (SRR), inflammatory (IRR), and replacement (RRR) root resorption were calculated. From this data the percentage of linear and area resorption was averaged for each group. Duncan multiple range t-test (P<0.05) revealed that teeth in which a pulpectomy with CH filling was done extraorally had significantly greater SRR than the rest of the groups; teeth in which a pulpectomy without CH filling was done extra orally had significantly greater RRR than teeth in which CH pulpectomy was delayed for 18 days; there was no significant difference in SRR. IRR or RRR when CH placement was delayed 4, 9, 14 or 18 days after replantation. Although it was not significant the overall resorption was least when CH pulpectomy was delayed 18 days.     

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.     

The effect of citric acid treatment on periodontal healing after replantation of permanent teeth

The aim of this study was to evaluate the effect of surface demineralization on the healing of 120 replanted teeth in fifteen 8- to 16-month-old dogs. Replanted teeth were divided into two groups (A and B). In group A, teeth were replanted following planing of the entire root surface. In group B, teeth were replanted following planing and surface demineralization with citric acid. Replanted teeth were splinted for 7 days, and observation periods were 3, 14 and 56 days. A total of 95 teeth and their surrounding tissues were examined histologically under a light microscope. Histological examination of specimens 3 days after replantation revealed that initial reunion between the root and the alveolar periodontal ligament fibres was via a fibrin-like network in both groups. Fourteen days after replantation histological observations showed superior healing in group B with regard to epithelial condition, periodontal ligament fibre reattachment to the root surface, resorption and functional arrangement of the periodontal ligament fibres. By 56 days after replantation, healing was superior in group A; group B was characterized by severe inflammatory and replacement resorption. These results indicated that surface demineralization had an initial positive effect, but later led to impaired healing.     

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.     

富血小板血浆对脱位再植牙牙周组织愈合影响的研究

目的:探讨局部应用富血小板血浆(platelet-rich plasma,PRP)对狗脱位牙再植后牙周组织愈合的影响.方法:将6只Beagle犬的第二切牙拔除,干燥放置60 min,按随机区组设计分为4组,A组为再植前根面及牙槽窝涂布PRP,7d后行根管充填术;B组为涂布PRP,未行根管充填术;C组为未涂布PRP,7 d后行根管充填术;D组为未涂布PRP,未行根管充填术.12周后进行组织学观察,分别计算每颗牙的正常牙周膜指数(正常牙周膜位点的百分率)和3种吸收指数(3种吸收位点的百分率),结果进行统计学分析.结果:A、C 2组各种吸收指数和正常牙周膜指数差异不明显;B组替代性吸收发生率较D组明显减低,正常牙周膜率则比D组明显增高.结论:在一定条件下局部应用PRP可减少非根管治疗再植牙替代性吸收的发生,并可促进其牙周组织的正常愈合.     

氢氧化钙根尖诱导术在年轻恒牙及外伤牙中的应用

目的 研究氢氧化钙根尖诱导术对保存年轻恒牙及外伤牙的作用。方法 观察93个牙进行牙根尖诱导术治疗的疗效。结果 治疗后仅出现早期牙髓炎症状77个牙中，牙根继续发育66个牙、根管变细而根长度不变10个牙。牙髓感染严重而未出现根尖周炎症状11个牙中，牙根继续发育3个牙，根管变细7个牙。根尖出现炎症5个牙中，仅有根管变细3个牙。结论 用氢氧化钙进行根尖诱导术是一种有效、可靠的治疗方法。     

Relationship between calcium hydroxide pH levels in the root canals and periodontal healing after replantation of avulsed teeth

Calcium hydroxide [Ca(OH)₂], when used as a root canal dressing, has been shown to promote periapical healing, induce formation of an apical hard tissue barrier (apexification), and arrest infection‐related root resorption. The main mechanism of action is thought to be the high alkalinity of Ca(OH)₂ ensuring a bactericidal or bacteriostatic effect upon microorganisms in the root canal and dentinal tubules. Several anatomical factors related to the root canal, such as the coronal access cavity, the apical foramen, the dentinal tubules, and existing resorption cavities on the root surface, all allow leakage of hydroxide ions from the root canal. The purpose of the present clinical study was to analyze pH changes in 63 permanent anterior teeth in which Ca(OH)₂ (Calasept^®) was used as an initial canal dressing after replantation and subsequent pulp necrosis had developed. The pH changes in the pulp canal were studied with relation to observation period, stage of root formation, healing of any periapical radiolucency, infection‐related root resorption, formation of an apical hard tissue barrier, and finally the radiographic appearance of Ca(OH)₂ in the canal (i.e. present or not). The study showed that several factors determined the pH level: the observation period (i.e. observation periods exceeding 6 months showed a significant drop in pH level below a pH of 10), an initial active inflammatory root resorption (tendency to be related to a drop in pH), and a subsequent progression of infection‐related resorption (the same tendency to be related to a drop in pH to below 10). The size of the apical foramen and the length of the pulp had no relation to pH change. The radiographic disappearance of Ca(OH)₂ in the root canal (loss of radiopacity of the canal dressing) was found to be significantly associated with a drop in pH (P=0.001). It was concluded that radiographic monitoring of the Ca(OH)₂ presence in the root canal is essential for endodontic treatment planning (i.e. when to replace Ca(OH)₂ or perform a permanent root filling). Furthermore, continuous activity of inflammatory root resorption may indicate a drop in pH and should result in replacement of new Ca(OH)₂. It should be noted that these findings apply to a Ca(OH)₂ product (Calasept^®) with no added radiopaque material.     

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.     

三种氢氧化钙制剂对年轻恒牙断裂抗力影响的体外研究

目的 体外比较3种氢氧化钙制剂根管充填后对年轻恒牙牙体断裂抗力的影响,以期为临床更合理地使用氢氧化钙制剂提供依据.方法 临床选取因正畸拔除的人前磨牙140颗,使用计算机产生的随机数分组法将其分为10组,每组14个样本.其中9组为实验组,1组为空白对照组.实验组在常规根管预备后,其中的3组根管内充填Ca(OH)2水糊剂(CⅠ、CⅡ和CⅢ组)、3组根管内充填Metapex糊剂(MⅠ、MⅡ和MⅢ组)、3组根管内充填Vitapex糊剂(ⅤⅠ、ⅤⅡ和ⅤⅢ组);空白对照组不进行根管充填.分别在根充后14 d对CⅠ、MⅠ和ⅤⅠ组、根充后1个月对CⅡ、MⅡ和ⅤⅡ组、根充3个月后对CⅢ、MⅢ和ⅤⅢ组离体牙样本进行断裂抗力测试;空白对照组于3个月时进行断裂抗力测试.使用SNK分析法对每组牙断裂抗力均值进行统计学分析.结果 3种糊剂根充14 d后对年轻恒牙牙体断裂抗力无显著影响,空白对照、CⅠ、MⅠ及ⅤⅠ组的断裂抗力分别为(591±72)、(536±107)、(547±113)、(570±123)N,各实验组与空白对照组相比差异均无统计学意义(P＞0.05);根充1个月后3种糊剂均可使年轻恒牙牙体断裂抗力显著下降,CⅡ、MⅡ及ⅤⅡ组的断裂抗力分别为(421±78)、(442±82)、(477±100)N,均显著低于空白对照组(P＜0.01);根充3个月后CⅢ、MⅢ及ⅤⅢ组的断裂抗力也均显著低于空白对照组(P＜0.01).结论 Ca(OH)2水糊剂、Metapex糊剂及Vitapex糊剂均可在根充1个月后对年轻恒牙牙体断裂抗力产生明显影响,建议临床中可将氢氧化钙作为短期(1个月以内)根管内封存药物使用;对治疗周期较长的病例,建议1个月后改用其他药物或治疗技术.