Histological and bacteriological study of pulps extirpated after luxation injuries

Abstract In a material of 637 luxated permanent teeth, it was found that 26 teeth (4.2%) which initially demonstrated the classical signs of pulp necrosis had reverted to normal appearance and sensibility at later examination, indicating that a revascularization and reinnervation process of the traumatized pulpal tissue had taken place. A histological and histobacteriological analysis was made of 66 pulps in the same population that had been extirpated due to suspected pulpal necrosis after injury, in order to examine whether similar changes could also have occurred in these teeth. It was found that the pulps studied were either non-infected (n = 27), infected (n= 11) or totally autolyzed (i.e. not enough tissue for histological examination (n = 28)). In contrast to teeth with autolyzed or infected pulp tissue, 12 of the 27 non-infected specimens showed signs of pulpal revascularization and/or apparent scattered cell survival. These pulps were assumed to have a potential for healing (i.e. revascularization and reinnervation of the pulp). Most clinical and radiographic parameters appeared not to be associated with pulpal infection of cell/tissue integrity. Only the length of the observation period and tenderness to percussion were found to be related to the histological status (i.e. presence or absence of pulpal infection, cellular versus acellular stroma). It was concluded that the present criteria for pulpal necrosis cannot discriminate between infected pulp necrosis and cases where healing might take place. Whether healing processes would actually lead to repair of the pulp could not be determined with the present material.     

Relationship between pulp dimensions and development of pulp necrosis after luxation injuries in the permanent dentition

Abstract A relationship between type of luxation injury, stage of root development and development of pulp necrosis after injury has been demonstrated. It was therefore decided to delve more deeply into the relationship between stage of root development and the later development of pulp necrosis after injury in a material of luxated permanent teeth. In this context, the diameter of the apical foramen and the distance from the apical foramen to the pulp horn, as measured on radiographs taken at the time of injury, were used as indicators of root development. In order to justify this approach, the precision of the measuring technique and the accuracy of the radiographic technique were studied. Regarding precision of the measuring technique, it was found that there was a 1% to 4.3% error of the means of all measurements for the various parameters and exposure techniques employed. With respect to accuracy of the radiographic technique, it was found that there was a systematic error in the radio-graphic technique which resulted in a median relative distortion of between 3.5% and 8% image magnification for the various parameters and the exposure techniques employed. These findings indicated that the measuring technique employed in the present investigation was reliable for studying the parameters in question. In a material of 226 extruded, intruded and laterally luxated maxillary permanent incisors, observed for up to 10 years, it was found that the development of pulp necrosis after injury was significantly related to the diameter of the apical foramen. For extruded and laterally luxated teeth, the smaller the diameter, the greater the probability of pulp necrosis. Intruded teeth with incomplete root development (i.e. radiographic diameters ≥1.2 mm) were associated with a much higher probability of pulp survival than teeth with complete root development (i.e. radiographic diameters ≤0.7 mm). The distance from the apical foramen to the pulp horn did not appear to be of importance in predicting pulp survival when diameter of the apical foramen was taken into account. Pulp survival after luxation injuries with displacement thus appears to be dependent upon the size of apical contact between the pulp and the periodontium.     

Apexogenesis after initial root canal treatment of an immature maxillary incisor – a case report

Aim To present a case where a traumatized, immature tooth still showed capacity for continued root development and apexogenesis after root canal treatment was initiated based on an inaccurate pulpal diagnosis. Summary Traumatic dental injuries may result in endodontic complications. Treatment strategies for traumatized, immature teeth should aim at preserving pulp vitality to ensure further root development and tooth maturation. A 9‐year‐old boy, who had suffered a concussion injury to the maxillary anterior teeth, was referred after endodontic treatment was initiated in tooth 21 one week earlier. The tooth had incomplete root length, thin dentinal walls and a wide open apex. The pulp chamber had been accessed, and the pulp canal instrumented to size 100. According to the referral, bleeding from the root made it difficult to fill the root canal with calcium hydroxide. No radiographic signs of apical breakdown were recorded. Based on radiographic and clinical findings, a conservative treatment approach was followed to allow continued root development. Follow‐up with radiographic examination every 3rd month was performed for 15 months. Continued root formation with apical closure was recorded. In the cervical area, a hard tissue barrier developed, which was sealed with white mineral trioxide aggregate (MTA). Bonded composite was used to seal the access cavity. At the final 2 years follow‐up, the tooth showed further root development and was free from symptoms. Key learning points

• ? Endodontic treatment of immature teeth may result in a poor long‐term prognosis.
• ? The pulp of immature teeth has a significant repair potential as long as infection is prevented.
• ? Treatment strategies of traumatized, immature permanent teeth should aim at preserving pulp vitality to secure further root development and tooth maturation.
• ? Radiographic interpretation of the periapical area of immature teeth may be confused by the un‐mineralized radiolucent zone surrounding the dental papilla.

     

Use of a removable splint in the treatment of subluxated, luxated and root fractured anterior permanent teeth in children

Aim: The aim of this study was to evaluate the prognosis of subluxated, luxated and root fractured teeth in children treated by removable splints, designed to stabilize mobile anterior teeth and eliminate occlusal trauma due to malocclusion. Material and methods: A total of 227 traumatized anterior teeth (91 subluxated, 105 luxated and 31 root fractured teeth) treated with a removable splint were observed for 3 years. The traumatized teeth were from 79 children aged between 6–12 years (mean 8 years 5 months). If a traumatized tooth was extremely mobile, a fixed splint was first made before the impression was taken for the removable splint. Two weeks after completion of the removable splint treatment, an impression was taken again to evaluate the occlusal relationship of pre‐ versus post‐treatment of removable splint. Results: The treatment period with a removable splint averaged 3 weeks in subluxated teeth, 3–5 weeks in luxated teeth, 4–6 weeks in apical third root fracture injuries, and more than 5 weeks in middle third root fracture injuries. All the subluxated teeth and 74.1% of the luxated teeth maintained their pulp vitality during the 3‐year follow‐up period. Two of 21 (9.5%) apical third root fracture teeth and three of five (60%) middle third root fracture teeth had pulp necrosis in the coronal fragments. Internal resorption was not found in any of the traumatized teeth. External replacement resorption was not found in subluxated and luxated teeth. All the root fractured teeth displayed transient external resorption around the fracture lines. The surface resorption appeared to be self‐limiting and not to threaten the retention of the tooth. Inflammatory resorption was observed in teeth with pulp necrosis, but in all cases this was reversed with endodontic treatment. Eight of 23 (39%) apical third root fractured teeth displayed replacement resorption in their apical fragments, but the resorption was not serious enough to extract the tooth. No obvious alteration in the occlusal relationship was found comparing pre‐ and post‐treatment casts. The removable splints appeared to positively affect healing after traumatic injuries, as evidenced by the low number of complications at the 3‐year follow‐up period.     

Pulp and periodontal healing of laterally luxated permanent teeth: results after 4 years

Abstract – Aim: To evaluate the pulp and periodontal healing of laterally luxated permanent teeth. Material and methods: Patients presenting with lateral luxation of permanent teeth during 2001–2002 were enrolled in this clinical study. Laterally luxated teeth were repositioned and splinted with a TTS/composite resin splint for 4 weeks. Immediate (prophylactic) root‐canal treatment was performed in severely luxated teeth with radiographically closed apices. All patients received tetracycline for 10 days. Re‐examinations were performed after 1, 2, 3, 6, 12 and 48 months. Results: All 47 laterally luxated permanent teeth that could be followed over the entire study period survived. In 10 teeth (21.3%), a prophylactic root‐canal treatment was performed within 2 weeks following injury. The remaining 37 teeth showed the following characteristics at the 4‐year re‐examination: 19 teeth (51.4%) had pulp survival (no clinical or radiographic signs or symptoms), nine teeth (24.3%) presented with pulp canal calcification, and pulp necrosis was seen in another nine teeth (24.3%), within the first year after trauma. None of the teeth with a radiographically open apex at the time of lateral luxation showed complications. External root resorption was only seen in one tooth. Conclusions: Laterally luxated permanent teeth with incomplete root formation have a good prognosis, with all teeth surviving in this study. The most frequent complication was pulp necrosis that was only seen in teeth with closed apices.     

Occurrence of pulp canal obliteration after luxation injuries in the permanent dentition

Abstract A material of 637 concussed, subluxated, extruded, laterally luxated and intruded permanent incisors was analyzed with respect to factors influencing the development of pulp canal obliteration (PCO) after injury. A total of 96 (15%) developed partial PCO; 9 of these (1% of the total material) went on to develop total PCO. Only 2 teeth exhibited yellow discoloration of the clinical crown and 1 showed grey discoloration. Sensibility to electrometric pulp testing of the teeth with PCO was not significantly different from sensibility of contralateral homologues at the final examination (except for after lateral luxation, where the teeth with PCO had a significantly lower perception threshold). PCO was significantly more frequent among teeth with incomplete root formation than in teeth where root formation was completed. Extrusion, lateral luxation and intrusion showed more frequent occurrence of PCO than did concussion and subluxation. Moreover, the use of orthodontic band/resin splints significantly increased the occurrence of PCO, presumably due to the additional trauma of forceful placement and cementation of orthodontic bands in contrast to the relatively passive placement of an acid-etch/resin splint. Based on previous and present clinical and radiographic findings concerning pulp response to luxation injuries, it is suggested that PCO is a sequel to revascularization and/or reinnervation of a damaged pulp after injury.     

Healing of 208 intraalveolar root fractures in patients aged 7–17 years

Abstract – This retrospective study consisted of 208 root-fractured, 168 splinted and 40 not splinted incisors in young individuals (aged 7–17 years) treated in the period 1959–1973 at the Pedodontic Department, Eastman Institute, Stockholm. Clinical and radiographic analyses showed that 69 teeth (33%) had developed hard tissue (fusion) healing of fragments. Interposition of periodontal ligament (PDL) and bone between the fragments was found in 17 teeth (8%). Interposition of PDL alone was found in 74 teeth (36%). Finally, non-healing with pulp necrosis and inflammatory changes between fragments was seen in 48 teeth (23%). Various clinical factors were analyzed for their relationship to the healing outcome with respect to healing/no healing and type of healing (hard tissue versus interposition of bone and/or PDL). Immature root and positive pulp sensitivity at time of injury was found to be significantly related to both pulp healing and hard tissue repair of the fracture. The same applied to concussion or subluxation of the coronal fragment compared to luxation with displacement (extrusive or lateral luxation). This relation was also represented by the variable millimeter diastasis between fragments before and after repositioning. Repositioning appeared to enhance the likelihood of both pulp healing and hard tissue repair. A positive effect of splinting, splinting methods (cap splints or orthodontic bands with an arch wire) or splinting periods could not be demonstrated on either pulp healing or type of healing (hard tissue versus interposition of bone and/or PDL). In conclusion, the findings from this retrospective study have cast doubts on the efficacy of long-term splinting and the types of splint used for root fracture healing. It is suggested that the role of splinting and splinting methods be examined in further studies.     

Pulp Response to Periodontal Disease: Novel Observations Help Clarify the Processes of Tissue Breakdown and Infection

IntroductionThis study evaluated the pulp response to periodontal disease of increasing severity.MethodsThe material comprised human teeth affected by moderate (n = 16) to severe (n = 48) periodontal disease and no clinically identified caries lesions. Specimens were obtained by extraction and were processed for histopathologic and histobacteriologic methods.ResultsIn 13 of 16 teeth with moderate periodontal disease and vital pulp, no frank accumulations of inflammatory cells were observed. In 22 of 32 teeth with severe periodontal disease and vital pulps, no distinct inflammatory cell accumulations were observed in any portion of the pulp when there was an intact or minimally damaged cementum layer in the corresponding areas. Intravascular bacterial aggregations were detected in pulp blood vessels in 6 teeth with symptomatic pulpitis and severe periodontal disease, which had not reached the root apex in 4 of them. Focal areas of infection and varying accumulations of acute and chronic inflammatory cells were observed throughout the pulp tissue and surrounding these infected blood vessels. When the periodontal pocket reached the apex of single-rooted teeth, the entire canal space was necrotic and colonized by bacteria, often forming biofilms. In multirooted teeth, the pulp response varied according to the root(s) affected. Intrapulpal calcifications were observed in 91% of the teeth. The pulp and cementum of the control teeth showed no pathologic changes or bacteria.ConclusionsThe pulp showed a significantly detectable response when the cementum coverage was lost or when the periodontal pocket reached the root apex. In the former condition, the pulp response was usually discrete, whereas in the latter, severe reactions usually developed. In some teeth, vessels with a compromised blood flow may serve as avenues for bacteria to invade the pulp via apical or lateral foramina. This indicates that in some teeth the pulp may undergo severe inflammation and necrosis even before the periodontal disease reaches the apical root segment.     

Effect of luxation injuries on permanent teeth

Abstract Trauma to the supporting tissues of the teeth are among the most common dental injuries, leading to such complications as pulp canal obliteration, necrosis and root resorption. The aim of this investigation was to study the outcome for young permanent teeth subjected to luxation injuries. From 108 dental records 171 teeth with injuries to the supporting tissue were selected. The material comprised 130 subluxated, 15 extruded, 9 intruded, 15 exarticulated and 6 laterally luxated teeth in children aged 6–19 years. Apart from luxation, 59 teeth (35%) had additional crown and root fractures. 65% of the teeth recovered without complications. 78% of the subluxated teeth and 24% of the luxated teeth showed uneventful posttraumatic healing. Concomitant uncomplicated crown fractures or root fractures without displacement of the coronal fragment did not interfere with the healing. Of 60 teeth with healing complications, 52 (87%) were subsequently recorded as healed, the remaining 8 were extracted or had progressive root resorption. Loss of pulp vitality and external root resorptions were the most often recorded complications (28% and 17% of the total material respectively). Pulp canal obliteration was noted in 3% of the cases. Extent of injury and degree of tooth maturity were found to be related to healing compliations.     

Prognosis of luxated permanent teeth — the development of pulp necrosis

Abstract A population of 400 patients, comprising 637 luxated permanent teeth was studied prospectively with respect to the development of pulp necrosis after luxation injuries. The patients were treated for traumatic dental injuries over a period of 10 years. While initial treatment was provided according to established treatment guidelines by the attending oral surgeon at the emergency room, follow-up examination and treatment was provided by one oral surgeon. It appeared that pulp necrosis occurred soon after injury, within 3 months after concussion, within the 1st yr after subluxation and extrusion, and might be diagnosed up to 2 yr after lateral- and intrusive luxation. While many factors, when considered one at a time, were found to have a significant or nearly significant died on the development of pulp necrosis (i.e. type of injury, age of patient, stage of root development, degree of dislocation, reduction/repositioning procedure, type of fixation, restorations in place at the lime of injury), a multivariate regression analysis revealed that when the type of injury (diagnosis) and stage of root development were taken into account, the effect of other factors was no longer significant. The risk of pulp necrosis increased with the extent of injury, i.e. concussion and subluxation represented the least risk, followed in ascending order by extrusive-, lateral-, and intrusive luxation. Moreover, teeth with completed root formal ion demonstrated a greater risk of pulp necrosis than teeth with incomplete root formation. No treatment effect could be demonstrated. However, as treatment was performed according to established guidelines, which might introduce bias, it would appear justified to conduct randomized clinical studies in order to determine the value of different forms of treatment (e.g. reduction and fixation of luxated teeth) to improve the prognosis with respect to the development of pulp necrosis after injury. In conclusion, the major factors influencing development of pulp necrosis after luxation injuries appear to be the extent of the initial injury to the pulp and periodontium, as reflected by the type of luxation, and the repair potential of the injured tooth, as reflected by the stage of root development.     

Deciduous Tooth Pulp Autotransplantation for the Regenerative Endodontic Treatment of Permanent Teeth With Pulp Necrosis: A Case Series

IntroductionIn young individuals, deciduous tooth pulp might be used as a natural, biologic scaffold for the regenerative endodontic treatment (RET) of young permanent teeth with necrotic pulps and apical periodontitis. The present case series demonstrates the clinical and radiographic outcomes of a novel RET using deciduous pulp autotransplantation in traumatized, necrotic young permanent incisors.MethodsFive previously traumatized maxillary incisors of four 8- to 11.5-year-old patients were treated with a RET protocol that used 2.5% NaOCl irrigation and placement of calcium hydroxide dressing in the first visit. After 4 weeks, the intracanal medication was removed, and the whole pulp tissue harvested from the neighboring maxillary deciduous canine was transplanted into the disinfected root canal without induced apical bleeding. Following placement of a mineral trioxide aggregate coronal barrier, the access cavities were restored with acid-etch resin composite. The root canals of donor primary canines were filled with calcium hydroxide-iodoform paste and were restored as with the permanent incisors.ResultsThree patients were followed-up for 24 months, and 1 patient for 12 months. All teeth demonstrated radiographic evidence of complete periapical healing, slight increase in dentinal wall thickness, and continued apical closure in the absence of clinical symptoms. A positive response to cold test was obtained in 1 incisor at 12 months and 2 at 24 months.ConclusionsBased on 12- and 24-month clinical and radiographic findings, the present cases demonstrate a favorable outcome of a RET protocol using deciduous pulp autotransplantation in young permanent incisors with pulp necrosis.     

Replantation of 400 avulsed permanent incisors. 2. Factors related to pulpal healing

Abstract Four hundred avulsed and replanted permanent teeth were examined for pulpal healing. In 110 teeth, the apical foramen was either open or half-open. In 16 teeth, the pulps were extirpated prophylactically. Thus, pulpal revascularization was considered possible in 94 teeth. Revascularization occurred in 32 teeth (34%). Pulp necrosis could usually be demonstrated after 3 weeks. Positive pulpal sensibility and radiographis signs of pulp canal obliteration were usually observed after 6 months. The effect of various clinical factors was examined, such as sex, age, type of tooth replanted, stage of root formation, type and length of extra-alveolar storage, clinical contamination of the root surface, type of cleansing procedure of the root surface, type and length of splinting and the use of antibiotics. Finally, the width of the apical foramen and the length of the root canal were measured on radiographs taken at the time of injury. A multivariate statistical analysis revealed that pulpal revascularization was more frequent in teeth with shorter distances from the apical foramen to the pulp horns. Furthermore, that wet storage (saliva and/or saline) for more than 5 min decreased the chance of pulpal revascularization; whereas dry extraalveolar storage had a monotonous effect on pulpal revascularization, i. e. decreasing chance of revascularization with increasing length of the extraalveolar dry storage. Based on these findings, immediate replantation after brief cleansing in either tap water or saline is recommended.     

Endodontic-orthodontic relationships: a review of integrated treatment planning challenges

Literature review There is a paucity of information on the concise relationship between endodontics and orthodontics during treatment planning decisions. This relationship ranges from effects on the pulp from orthodontic treatment and the potential for resorption during tooth movement, to the clinical management of teeth requiring integrated endodontic and orthodontic treatment. This paper reviews the literature based on the definition of endodontics and the scope of endodontic practice as they relate to common orthodontic-endodontic treatment planning challenges. Literature data bases were accessed with a focus on orthodontic tooth movement and its impact on the viability of the dental pulp; its impact on root resorption in teeth with vital pulps and teeth with previous root canal treatment; the ability to move orthodontically teeth that were endodontically treated versus nonendodontically treated; the role of previous tooth trauma; the ability to move teeth orthodontically that have been subjected to endodontic surgery; the role of orthodontic treatment in the provision for and prognosis of endodontic treatment; and, the integrated role of orthodontics and endodontics in treatment planning tooth retention. Orthodontic tooth movement can cause degenerative and/or inflammatory responses in the dental pulp of teeth with completed apical formation. The impact of the tooth movement on the pulp is focused primarily on the neurovascular system, in which the release of specific neurotransmitters (neuropeptides) can influence both blood flow and cellular metabolism. The responses induced in these pulps may impact on the initiation and perpetuation of apical root remodelling or resorption during tooth movement. The incidence and severity of these changes may be influenced by previous or ongoing insults to the dental pulp, such as trauma or caries. Pulps in teeth with incomplete apical foramen, whilst not immune to adverse sequelae during tooth movement, have a reduced risk for these responses. Teeth with previous root canal treatment exhibit less propensity for apical root resorption during orthodontic tooth movement. Minimal resorptive/remodelling changes occur apically in teeth that are being moved orthodontically and that are well cleaned, shaped, and three-dimensionally obturated. This outcome would depend on the absence of coronal leakage or other avenues for bacterial ingress. A traumatized tooth can be moved orthodontically with minimal risk of resorption, provided the pulp has not been severely compromised (infected or necrotic). If there is evidence of pulpal demise, appropriate endodontic management is necessary prior to orthodontic treatment. If a previously traumatized tooth exhibits resorption, there is a greater chance that orthodontic tooth movement will enhance the resorptive process. If a tooth has been severely traumatized (intrusive luxation/avulsion) there may be a greater incidence of resorption with tooth movement. This can occur with or without previous endodontic treatment. Very little is known about the ability to move successfully teeth that have undergone periradicular surgical procedures. Likewise, little is known about the potential risks or sequelae involved in moving teeth that have had previous surgical intervention. Especially absent is the long-term prognosis of this type of treatment. During orthodontic tooth movement, the provision of endodontic treatment may be influenced by a number of factors, including but not limited to radiographic interpretation, accuracy of pulp testing, patient signs and symptoms, tooth isolation, access to the root canal, working length determination, and apical position of the canal obturation. Adjunctive orthodontic root extrusion and root separation are essential clinical procedures that will enhance the integrated treatment planning process of tooth retention in endodontic-orthodontic related cases.     

年轻恒牙脱出性损伤后牙髓预后及相关因素分析

目的 评估年轻恒牙脱出性损伤后牙髓组织的预后,分析可能影响预后的相关因素.方法 对2000年1月至2006年12月于北京大学口腔医学院·口腔医院儿童口腔科就诊且资料完整、观察期≥6个月的157例(238颗牙)年轻恒牙外伤病历进行回顾性研究,记录患者性别及年龄、外伤类型、外伤牙位、牙根发育情况、外伤后就诊时间、是否接受急诊处理以及牙髓组织预后类型.应用Logistic回归模型分析与牙髓预后相关的因素.结果 符合纳入标准的外伤病历共157份,外伤牙238颗,其中38颗(16.0%)出现牙髓坏死,5颗(2.1%)出现髓腔钙化,牙髓存活195颗(81.9%).挫入移位牙髓坏死发生率最高(66.7%).牙根发育情况和外伤类型与牙髓组织预后具有显著相关性(P<0.05).结论 牙齿脱出性损伤中,挫人移位最易发生牙髓坏死.牙根发育情况和外伤类型与脱出性损伤牙齿的牙髓预后具有相关性.     

Diagnosis and treatment of pulp necrosis in permanent anterior teeth with root fracture

A follow-up study was made of 20 traumatized permanent incisors with pulp necrosis observed as a sequel to root fracture. The material included 19 patients aged 8–17 years (mean 11.6 years) at the time of injury. Negative response to electric stimulation was noted in 16 teeth from the first examination. In four teeth an initial positive response changed to negative within 2–9 months. The negative response was supported by additional signs and symptoms of necrosis in 19 teeth. Radiolucencies adjacent to the fracture line or coronal discolorations were the most important diagnostic factors. Discolorations occurred within 2 months, whereas radiographic changes in the fracture area took from 3 to .5 months. to develop. Four teeth were extracted without attempting endodontic therapy. Endodontic treatment confined to the coronal fragment was performed in 16 teeth. In most cases the canal was filled temporarily with calcium hydroxide until a closure at the fracture site was observed. Two apical fragments showing radiographic changes were surgically removed in conjunction with the permanent filling of the coronal fragments. During the postoperative observation period one tooth was extracted due to communication between the fracture area and the oral cavity. The treatment of the remaining 15 teeth was judged as successful after a mean observation period of 4.2 years, ranging from 2 to 5 years.     

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根管闭锁（pulp canal obliteration,PCO）是牙外伤后常见的并发症之一,通常发生于青少年,多见于年轻恒牙。PCO的发生机制尚不明确,可能是外伤后受损的牙髓出现血管再生和（或）神经再生的结果,也可能是由于外伤本身或者复位固定外伤牙后牙髓血液流量的改变导致。对于牙外伤后出现PCO的患牙,一些学者认为根管治疗不仅可以避免出现根尖周炎症,而且有利于患牙的美容修复。大多数学者则认为可对患牙进行长期的随访观察,只有伴有PCO的外伤牙出现牙髓坏死或者发展为根尖周炎时才考虑根管治疗,而且根管治疗对PCO的患牙是一项挑战,在技术上是复杂的。总之,为了及时检测到PCO的发生,对外伤牙定期随访和密切观察是十分必要的。     

三种预备方法对直根管根尖封闭性的影响

根管治疗术是治疗口腔常见疾病＂牙髓病和根尖周病＂的最根本和最有效的方法。本研究的目的是观察应用步退法[1]和冠向下法根管预备对直根管根尖封闭性的影响,以供临床参考。     

Multiple pulp stones and shortened roots of unknown etiology

An unusual case of generalised pulpal calcifications (pulp stones) with normal clinical crowns is reported in a 13-year-old boy. Radiographic examination revealed pulp stones in the single rooted and premolar teeth, situated at the midroot level, with the roots bulging around them. The apical portion of the roots, periodontal ligament space, and surrounding bone had a normal radiographic appearance, apart from the upper premolars, and no periapical pathology was discernible. The upper premolars exhibited considerably shortened roots. No medical, dental, or family history was found to be contributory. Reviewing the literature revealed similar cases, but with differing diagnoses including dentine dysplasia (DD) or idiopathic cases. This report suggests either a variation of DD or possibly a new nonsyndromic dentine defect, and highlights the difficulties in establishing a definitive diagnosis by traditional methods. The recent discovery that mutation of the bicistronic dentine sialophosphoprotein gene (DSPP) is involved in DD may provide solutions to this problem.     

Treatment of a Large Cystlike Inflammatory Periapical Lesion Associated with Mature Necrotic Teeth Using Regenerative Endodontic Therapy

Introduction

Regenerative endodontic therapy is currently used to treat immature permanent teeth with necrotic pulp and/or apical periodontitis. However, mature teeth with necrotic pulp and apical periodontitis have also been treated using regenerative endodontic therapy. The treatment resulted in resolution of apical periodontitis, regression of clinical signs and symptoms but no apparent thickening of the canal walls, and/or continued root development. A recent study in an animal model showed that the tissues formed in the canals of mature teeth with apical periodontitis after regenerative endodontic therapy were cementumlike, bonelike, and periodontal ligament–like tissue with numerous blood vessels. These tissues are similar to the tissues observed in immature permanent teeth with apical periodontitis after regenerative endodontic therapy.

Methods

A 23-year-old woman had a history of traumatic injury to her upper anterior teeth when she was 8 years old. Subsequently, #8 developed pulp necrosis and an acute apical abscess and #7 symptomatic apical periodontitis. The apex of #8 was slightly open, and the apex of #7 was completely formed. Instead of nonsurgical root canal therapy, regenerative endodontic therapy was attempted, including complete chemomechanical debridement on #8 and #7. This was based on the premise that filling of disinfected root canals with the host's biological vital tissue might be better than filling with foreign materials.

Results

After regenerative endodontic therapy of #8 and #7, there was radiographic evidence of periapical osseous healing and regression of clinical signs and symptoms. The pulp cavity of #8 decreased in size, and the apex closed. The pulp cavity of #7 appeared to be obliterated by mineralized tissue. These indicated ingrowth of new vital tissue into the chemomechanically debrided canals.

Conclusions

Regenerative endodontic therapy of mature teeth with apical periodontitis and apical abscess can result in the regression of clinical signs and/or symptoms and healing of apical periodontitis but no apparent thickening of the canal walls or continued root development. Filling of the disinfected canals with the host's vital tissue may be better than with foreign materials because vital tissue has innate and adaptive immune defense mechanisms.     

Oral manifestations of Ehlers-Danlos syndrome type VII: histological examination of a primary tooth

A two-year, 2-month old girl with Ehlers-Danlos syndrome Type VII is described. The patient presented with bleeding after tooth brushing, and exhibited microdontia and yellow discoloration of teeth. She had carious teeth, but did not exhibit periodontal disease, poor wound healing after extraction, radiographic evidences of pulp stones, or malformed roots. Microscopic examination of a decalcified section of an extracted tooth stained with H & E demonstrated some inclusions in the dentin, around which collagen was either missing or scanty, as confirmed by counterstaining with van Gieson's solution. The sections of pulp stained with van Gieson's solution showed an abnormal pattern of fibrous tissue. Furthermore, the radiopacity of the dentin of this patient was significantly higher than that of the control dentin.