The influence of orthodontic treatment on previously traumatized permanent incisors.

The reaction of previously traumatized teeth to orthodontic force application was investigated. Four groups of children were examined: group T comprised 56 children who encountered trauma to their maxillary incisors; group O comprised 29 orthodontic patients with intact incisors; group TO comprised 28 previously traumatized orthodontic patients; and group C served as the control group (n = 26). Orthodontic treatment was restricted to tipping movement executed only by means of removable appliances. Groups T, O, and TO were followed up longitudinally by means of clinical and radiographic examinations. In most of the cases the reported trauma occurred to teeth with completed roots and affected the crown only. Group TO presented the highest, though relatively moderate, prevalence of root resorption (27.8 per cent) and was followed by groups O and T (6.7 and 7.8 per cent, respectively) while in the control group no resorption was observed. Electrical pulp testing revealed the highest prevalence of loss of tooth vitality in group TO (7.3 per cent) in which the highest prevalence of pulp obliteration was also found. It can be concluded that the combination of trauma with orthodontic tipping renders the teeth more susceptible to complications, especially to root resorption and loss of vitality.     

应用激光多普勒技术检测牙髓血流的初步研究

目的　探索利用激光多普勒血流仪研究牙髓血流的可行性。方法　使用JI 2 0 0型微循环激光动态分析仪 ,检测 80颗正常上颌切牙、15颗死髓牙的牙髓血流状况 ,并对另 16颗深龋患牙治疗前、后的牙髓血流状况进行对比观察。结果　正常上颌切牙左右侧及男女性别间无差异 ,上中切牙牙髓血流量略大于上侧切牙。由死髓牙测得的流量值显著小于正常对照。 16颗深龋患牙治疗前牙髓血流量皆高于正常对照组 ,治疗后有 15颗患牙的血流量很快降至正常 ,有 1颗患牙在治疗后血流量无明显变化 ,最终发生牙髓坏死。结论　利用激光多普勒血流仪研究牙髓血流是可行的     

Traumatic crown fractures in permanent incisors with immature roots: a follow-up study

Abstract – A follow-up study of crown fractured permanent incisors with incomplete root formation was carried out in a group of patients, aged 6–12 years, over a 5-year-period in the Dental Clinic of the University of Verona, Italy. The number of injured patients was 55, representing 84 injured incisors. All patients were followed clinically and radiographically using a standardized follow-up protocol. The most common type of trauma was fracture of enamel and dentine without pulpal exposure (80%) and the most common type of treatment was restoration with the acid-etch composite resin technique (46%). Bonding of the crown fragment was performed in 10 instances (12%). At the 5-year-control all teeth with fracture of the enamel had no pulp complications. Four of 67 teeth (6%) with fracture of the enamel and dentine without pulpal involvement showed pulp necrosis and 1 tooth showed pulp obliteration (1.5%). Eight of 14 teeth (57%) with fractures of the enamel and dentine with pulp involvement showed pulp necrosis. Aesthetically 36 of the restored teeth were deemed satisfactory (43%). In 9 teeth the bonded fragment had to be rebonded. 14 teeth were considered unsatisfactorily restored due to wear of the composite (17%). 34 restored teeth had to be retreated because of a new trauma (40%). In one tooth a previous bonded fragment had to be rebonded. These results confirmed that crown fractures without pulp involvement in permanent incisors with incomplete root formation have a low percentage of pulp complications, while 60% of the teeth with crown fractures with pulp involvement had pulp complications.     

Traumatized primary anterior teeth. Prognosis related to calcific reactions in the pulp cavity.

The frequency of a complicating pulp necrosis and the process of the physiologic root resorption were studied in traumatized primary teeth exhibiting partial or total pulp obliteration. The material comprised 88 incisors in 72 children aged 0.7--5.7 years (mean 2.9 years) at the time of injury. Trauma had resulted either in subluxation (25 teeth), or luxation (13 teeth), whereas the type of injury was unknown in 50 teeth. All cases were observed until eruption of the permanent incisors. Forty-four teeth initially displayed a reversible greyish color. The ultimate finding observed in all teeth was, however, varying degrees of yellow discoloration. Periapical pathologic findings indicative of pulp necrosis were observed in 9 teeth, from 1.6--4 years (mean 3 years) after the time of injury. Extraction was performed immediately, and none of the successional teeth showed developmental disturbances. The process of root resorption was classified as normal in all primary teeth. Subsequent eruption of the permanent successors occurred without any registered complications.     

Long-term prognosis of traumatized permanent anterior teeth showing calcifying processes in the pulp cavity

ABSTRACT— 122 traumatized teeth with radiographic evidence of abnormal hard tissue formation in the pulp cavity were examined 10–23 years (mean 16 years) after the time of injury. Judged radiographically, partial obliteration (pulp chamber not discernible, root canal markedly narrowed but clearly visible) had occurred in 44 teeth (36%). Normal periradicular conditions were found in all teeth with partial obliteration. Seventy-eight teeth (64%) were recorded as totally obliterated. Pathologic periradicular changes indicating pulp necrosis as a sequel to the total obliteration were observed in 16 teeth (21%). The late development of pulp necrosis was significantly related to teeth classified as severely injured, and to teeth with complete root formation at the time of injury. Furthermore, a comparatively rapid progress of the calcifying process appeared to be correlated with periradicular radiolucency.     

Long-term prognosis of traumatized permanent anterior teeth showing calcifying processes in the pulp cavity.

122 traumatized teeth with radiographic evidence of abnormal hard tissue formation in the pulp cavity were examined 10-23 years (mean 16 years) after the time of injury. Judged radiographically, partial obliteration (pulp chamber not discernible, root canal markedly narrowed but clearly visible) had occurred in 44 teeth (36%). Normal periradicular conditions were found in all teeth with partial obliteration. Seventy-eight teeth (64%) were recorded as totally obliterated. Pathologic periradicular changes indicating pulp necrosis as a sequel to the total obliteration was observed in 16 teeth (21%). The late development of pulp necrosis was significantly related to teeth classified as severely injured, and to teeth with complete root formation at the time of injury. Furthermore, a comparatively rapid progress of the calcifying process appeared to be correlated with periradicular radiolucency.     

Pulp test response of the maxillary anterior teeth in cleft palate patients

The relative pulpal responsiveness of the six maxillary incisors to electrical and cold thermal stimuli was tested in patients with complete unilateral and bilateral clefts. The six maxillary anterior teeth were tested at random to electrical stimuli. After a 5-minute interval, the same teeth were tested at random to cold stimuli with an ice pencil. Unilateral and bilateral cleft palate patients had statistically significant higher mean electrical pulp test thresholds for the maxillary anterior teeth than the noncleft palate patients. No statistically significant difference between unilateral and bilateral cleft palate patients was found in electric pulp test responses of the maxillary anterior teeth. No statistically differences in electric pulp test responses and cold test responses of the maxillary anterior teeth in both cleft palate and noncleft palate individuals based on differences in sex were observed. No statistically significant difference in cold test responses were observed between cleft palate and noncleft palate patients. Cleft palate patients who completed orthodontic treatment within 1 year of testing showed elevated mean electrical pulp test thresholds as did noncleft palate patients who received orthodontic treatment within 1 year of testing.     

Reattachment of anterior teeth fragments using a modified Simonsen’s technique after dental trauma: report of a case

Abstract – This is a case report of a 9‐year‐old boy with complicated crown fractures of two traumatized teeth: left maxillary central and lateral incisors. The central incisor presented a small pulpal exposure of approximately 1 mm and the lateral incisor had an ulcerated and exposed pulp. Endodontic management included direct pulp capping, partial pulpotomy, and restorative management including reattachment of the teeth fragments using a modified Simonsen’s technique. The reattached fragments were assessed clinically and radiographically at 12 months. The teeth remained vital, there were no color changes, and the restorations had an acceptable appearance.     

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.     

Prognosis of root-fractured permanent incisors

Abstract The prognosis of 56 root-fractured permanent incisors was evaluated clinically and radiographically for 2 to 31 years. Information about initial case histories, examination and treatment of root-fractured teeth were recorded retrospectively from patient cards. Most of the-root fractures occurred in the 16–20 year age group (38%) followed by the 11–15 year age group (29%). Males were involved more often than females. Fifty-two percent of the patients visited the dental clinic with in the first week, while 48% did so 1 month-31 years later alter the injury. The leading cause of root fractured injuries was falls (46%) and mostly involved one tooth (71%). Maxillary central incisors were the most often affected teeth (95%). The most common type of root fracture was in the middle third of the root (57%) followed by apical part (34%). About 59% of untreated or splinted teeth maintained their vitality. Healing with connective tissue was observed in 19 teeth, with calcified tissue in 15 teeth and with osseous tissue in only one tooth. There was partial or complete obliteration of the pulp space in these healed cases (62.5%). The formation of pulpal hard tissue produced no additional clinical problems. Partial or total pulp necrosis were noted in 21 (37.5%) teeth. Endodontic treatment was successful in 12 cases. The remaining 9 teeth were extracted due to the loss of marginal alveolar bone and apical periodontitis.     

Pulpal reactions following experimental acute trauma of concussion type on immature dog teeth

Abstract The pulpal reactions of 14 immature incisors of two dogs were histopathologically evaluated 45 days after experimental mechanical blows that did not, as shown by post-traumatic clinical examination, cause fracture, displacement or loosening of the teeth. The more significant pulpal reactions in all specimens were the coagulation necrosis of the coronal pulp and the hyalinization of the central region of the radicular pulp. Dystrophic calcifications within coronal or radicular necrotic tissue, and absence of inflammatory infiltration were also observed in all traumatized teeth.     

Sequelae and prognosis of intruded primary incisors: a retrospective study.

PURPOSE: This study was designed to assess the sequelae and prognosis of intruded primary incisors. METHODS: Of 196 children who visited the emergency clinic due to intrusion of 310 maxillary primary incisors, 110 children (172 teeth) were available for follow-up examination (study group). Eighty-six children (138 teeth) did not show for the follow-up examination (non-respondents group). Male/female ratio was 1.7:1. Age range of children at time of injury was 12-72 months (mean 28). Follow-up time ranged between 0 and 59 months (mean 27). RESULTS: Fifty-seven percent of all teeth were completely intruded. In 80%, the root was pushed labially. All but two ankylosed teeth re-erupted, and 37% of these re-erupted into an ectopic position. Completely intruded incisors re-erupted into an ectopic position in a higher percentage (45%) than partially intruded teeth (30%). Fifty-two percent of the teeth presented pulp canal obliteration (PCO). Sixty-four percent of the completely intruded incisors presented PCO compared to 40% of partially intruded teeth. Arrest of dentin apposition was found in 15% of the teeth, and was not affected by the degree of intrusion. Twenty-three teeth were extracted shortly after the injury due to suspect of contact with the developing permanent successor (19 teeth) and severe caries (4 teeth). Sixty-eight percent of the intruded teeth survived more than 36 months after the injury. Twenty-three percent were extracted due to periodontal breakdown and 5% due to repeated trauma. Antibiotic therapy did not have any effect on the survival rate. CONCLUSION: The majority of intruded primary incisors may re-erupt and survive with no complications after more than 36 months post trauma even in cases of complete intrusion and fracture of the labial bone plate.     

Longitudinal clinical and radiographic evaluation of severely intruded permanent incisors in a pediatric population

Abstract – Intrusion is defined as the axial dislodgment of the tooth into its socket and is considered one of the most severe types of dental trauma. This longitudinal outcome study was undertaken to evaluate clinically and radiographically severely intruded permanent incisors in a population of children and adolescents. All cases were treated between September 2003 and February 2008 in a dental trauma service. Clinical and radiographic data were collected from 12 patients (eight males and four females) that represented 15 permanent maxillary incisors. Mean age at the time of injury was 8 years and 9 months (range 7–14 years and 8 months). Mean time elapsed to follow‐up was 26.6 months (range 10–51 months). The analysis of data showed that tooth intrusion was twice as frequent in males. The maxillary central incisors were the most commonly intruded teeth (93.3%), and falling at home was the main etiologic factor (60%). More than half of the cases (53.3%) were multiple intrusions, 73.3% of the intruded teeth had incomplete root formation and 66.6% of the teeth suffered other injuries concomitant to intrusion. Immediate surgical repositioning was the treatment of choice in 66.7% of the cases, while watchful waiting for the tooth to return to its pre‐injury position was adopted in 33.3% of the cases. The teeth that suffered additional injuries to the intrusive luxation presented a fivefold increased relative risk of developing pulp necrosis. The immature teeth had six times more chances of presenting pulp canal obliteration that the mature teeth and a lower risk of developing root resorption. The most frequent post‐injury complications were pulp necrosis (73.3%), marginal bone loss (60%), inflammatory root resorption (40%), pulp canal obliteration (26.7%) and replacement root resorption (20%). From the results of this study, it was not possible to determine whether the type immediate treatment had any influence on the appearance of sequelae like pulp necrosis and root resorption after intrusive luxation, but the existence of additional injuries and the stage of root development influenced the clinical case outcome in a negative and positive manner, respectively.     

A multidisciplinary approach to the treatment of an intruded maxillary permanent incisor complicated by the presence of two mesiodentes

Treatment of a traumatically intruded maxillary incisor with an immature apex remains controversial. Treatment options include observation, surgical repositioning, or orthodontic forced eruption. Likewise, the ideal timing of surgical removal of a mesiodens is highly controversial: immediate versus delayed intervention. The complications associated with untreated supernumerary teeth include: overretention of primary teeth, delayed eruption of permanent incisors, rotations, impaction, diastema, pulp necrosis and root resorption. Less common sequelae include enlarged follicular sacs, cystic degeneration and nasal eruption. This paper describes another risk factor associated with delayed removal of a mesiodens previously not mentioned in the dental literature, namely potential complications arising from a traumatic injury, in particular intrusion, of the maxillary permanent incisors.     

Pulp canal obliteration after Le Fort I osteotomy

A longitudinal study of 51 patients was carried out to determine the frequency of pulp canal obliteration (PCO) after Le Fort I osteotomy for the correction of dentofacial anomalies and to analyse pre- and peroperative factors influencing the development of PCO. PCO developed in 14 (2.3%) of 617 maxillary teeth followed for an average period of 28 months (range 11-59). The highest frequency of PCO was demonstrated in canines (6.0%) and premolars (4.4%). Total PCO was present in 9 teeth and partial PCO in 5 teeth. PCO was more frequent among teeth adjacent to a vertical interdental osteotomy than in teeth with no relation to a vertical osteotomy (p less than 0.0001). Change in blood supply after the operation was suggested to be responsible for PCO, although it might have been effected by the combined surgical and orthodontic treatment. Long-term follow-up, including periapical radiographs, of teeth with PCO is suggested, as pulp necrosis may develop many years after surgery.     

Pulp-test responses in orthodontic patients

The diagnosis of orofacial pain is complicated in the orthodontic patient as treatment-induced alterations to pulpal physiology may result in altered responses to pulp-test stimuli. Thirty-three subjects commencing fixed orthodontic treatment and another 15 subjects not undergoing orthodontic treatment were used in this study. Cold and electrical stimuli were applied to the maxillary incisor teeth prior to treatment, after the placement of fixed appliances and at regular intervals for both groups for up to 252 days. At baseline, response thresholds to electric testing were typically higher for orthodontic subjects, particularly for the lateral incisors. For the non-orthodontic group, the response threshold over the 252 days was relatively constant. For the orthodontic group, application of force immediately increased the response threshold to electric pulp testing, which peaked after two months. By day 252, response means for lateral incisors still remained elevated. Responses to thermal testing were more consistent and reliable. The results of this study indicate that dental practitioners should interpret responses to electric pulp testing cautiously in orthodontic patients and that thermal testing with carbon dioxide snow may be more reliable.     

Response of Class II molecule-expressing cells and macrophages to cavity preparation and restoration with 4-META/MMA-TBB resin

AIM: The aim was to test the hypothesis that the resin and bonding agent 4-META/MMA-TBB (4-META), has the potential to prevent transdentinal antigenic challenges. METHODOLOGY: Class I cavity preparation and immediate restoration with 4-META were made in the maxillary right first molars of 36 six-week-old Wistar rats. Contralateral teeth with an unrestored cavity served as positive control (cavity without 4-META) group. The maxillary first molars of 12 age-matched normal rats (total 24 teeth) were also examined as negative control (intact tooth group). At 3 or 28 days after cavity preparation, the teeth were subjected to immunoperoxidase staining using OX6 (anticlass II molecules) and ED1 (antimacrophages) as primary antibodies. RESULTS: A total of 10 teeth were not available for histological examination. In the teeth filled with 4-META at 3 days, the density of OX6+ and ED1+ cells in the coronal pulp was significantly higher than that in the intact tooth group. At 28 days, formation of sound reparative dentine was noted and the density of the immunocompetent cells was comparable to the intact teeth. In the teeth without 4-META at 3 days, pulpal abscess was observed in 14 out of 16 and the density of OX6+ and ED1+ cells was significantly increased (P < 0.001, paired t-test) compared with the 4-META group. Partial pulp necrosis had developed in the teeth without 4-META at 28 days. CONCLUSIONS: Restoration with 4-META significantly reduced transdentinal antigenic challenges. This property may have special implications for 4-META's capacity to protect the dentine/pulp complex.     

Laser doppler flowmetry in the assessment of tooth vitality after Le Fort I osteotomy

The aim of the present study was to evaluate pulp vitality in 15 patients, 11 to 29 months after a Le Fort I osteotomy. Assessment of pulpal blood flow was obtained by means of laser Doppler flowmetry, and it was measured bilaterally from the first maxillary premolar to the central incisor. The results were compared with those obtained by electric pulp testing in the same teeth. In addition, periodontal ligament perception was evaluated by applying axial loads to the central incisors. Radiographs were also studied. Fourteen subjects served as a control group. There was no significant difference between the level of pulpal blood flow in the teeth of the operated group compared with the control group. Twenty-one per cent of the teeth in the group operated on were insensitive to electric pulp testing, and in the remaining 79% the mean threshold was significantly higher than in the corresponding teeth in the control subjects. Similarly, the axial load threshold for the incisors for the control subjects was below 5 g, but in the group operated on 66% had a threshold above 5 g. These experiments clearly demonstrate that teeth without normal innervation can have an intact blood supply and be vital.     

Dentin and osteodentin matrix formation in apicoectomized replanted incisors in cats

The reestablishment and rate of osteodentin and dentin matrix formation in 27 apicoectomized replanted and 20 control incisors in cats were studied after Procion H8-BS vital staining. In control teeth the pattern of matrix formation differed in the various pulpal zones, with a higher rate of matrix formed toward apical areas, most dominantly in maxillary incisors. Osteodentin formation could be traced after a lag period of more than 10 days after replantation. Thirty and 60 days postoperatively osteodentin matrix was found in the total pulpal length in 83% and 73% of the teeth, respectively. A common finding was a tubular osteodentin matrix in the pulpal apical third in the replanted teeth. Tubular osteodentin matrix was, however, present most incisally in some teeth 60 days postoperatively. Internal resorption corresponding to outer cervical lesions dominated the pulpal reactions in the maxillary replanted teeth after 60 days. It is concluded that under the present experimental conditions the pulp tissue possesses a high healing potential and that the osteodentin formation reflects the pulpal healing pattern after replantation traumas. The results also indicate that successful pulpal healing depends on unexposed dentinal tubules.     

Peroxide penetration into the pulp from whitening strips

It was observed that externally applied bleaching gels may penetrate into the pulp chamber. This study was conducted to evaluate the peroxide diffusion from two whitening strips into the pulp chamber. Twenty-four, human, extracted, maxillary central teeth were separated into three groups (n = 8). All teeth were sectioned 3-mm apical to CEJ, the intracoronal pulp tissue was removed, and the pulp chamber was filled with acetate buffer. Vestibuler crown surfaces of teeth in the experimental groups were subjected to whitening strips; the teeth in the control group were exposed only to distilled water. The acetate buffer solution in each tooth was transferred to the tube. Leuco-crystal violet and enzyme horseradish peroxidase also were added to the tube. The pulpal peroxide was determined spectrophotometrically. The results indicated that the whitening strip containing 14% hydrogen peroxide presented a higher pulpal peroxide penetration than 6.5 % hydrogen peroxide (p < 0.001).