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Permanent Incisors (permanent + incisor)
Kinds of Permanent Incisors Selected AbstractsTraumatic injuries to permanent teeth in Turkish children, AnkaraDENTAL TRAUMATOLOGY, Issue 3 2009Ceyhan Altun From a total of 4956 children aged 6,12 years (mean age: 8.91 ± 1.95) applying to the Center, 472 children (9.5%) were found to have suffered dental injuries during a period of 2 years. Injuries were classified according to drawings and texts based on the WHO classification system, as modified by Andreasen and Andreasen. Injury rates were highest among children age 6 and ages 8,10. The most frequently injured permanent teeth were the maxillary central incisors (88.2%), and the maxillary right central permanent incisor made up 47.2% of all injured teeth. The most common cause of dental trauma was falling while walking or running (40.3%). Most injuries involved a single tooth (64.8%). The most common type of injury was enamel fracture (44.6%). There was a significant difference in gender, where boys more often suffered from a dental hard tissue and pulp injury than girls (P = 0.019), whereas there was no difference in gender (P = 0.248) in the distribution of periodontal injuries. Injuries were found to occur more frequently during the summer (P < 0.001). Children with increased overjet were 2.19 times more likely to have dental injuries than other children. Considering that the incidence of traumatic dental injury is highest among children ages 6 and ages 8,10 as well as the fact that patients with increased overjet are more prone to dental trauma, preventive orthodontic treatment in early mixed dentition may play an important role in reducing traumatic dental injuries. [source] Surgical repositioning of a traumatically intruded permanent incisor in a patient with rheumatic fever: case reportDENTAL TRAUMATOLOGY, Issue 1 2009Rosana Sales Dias However, it is one of the most severe types of dentoalveolar trauma. By definition, intrusive luxation consists of the axial displacement of the tooth into the alveolar bone, accompanied by comminution or fracture of the alveolar bone. Here we report the treatment management of a traumatically intruded immature permanent central incisor by surgical repositioning undertaken in a 10-year-old child with rheumatic fever 10 days after sustaining a severe dentoalveolar trauma. The intraoral examination showed the complete intrusion of the permanent maxillary right central incisor and the radiographic examination revealed incomplete root formation. Prophylactic antibiotic therapy was prescribed and the intruded tooth was surgically repositioned and endodontically treated thereafter. The postoperative course was uneventful, with both clinically and radiographically sound conditions of the repositioned tooth up to 3 years and 2 months of follow-up. These outcomes suggest that surgical repositioning combined with proper antibiotic prophylaxis and adequate root canal therapy may be an effective treatment option in cases of severe intrusive luxations of permanent teeth with systemic involvement. [source] Change in supporting tissue following loss of a permanent maxillary incisor in childrenDENTAL TRAUMATOLOGY, Issue 6 2007Helen D. Rodd Abstract,,, Alveolar bone resorption is an inevitable consequence of tooth loss and may be detrimental to long-term dental aesthetics and function. The aim of the present study was to quantify the degree of tissue resorption following the loss of a permanent incisor in a young population. The study group comprised 11 boys and five girls who all required the extraction of a permanent maxillary central incisor due to trauma-related sequelae. Mean age at tooth loss was 10.8 years. Upper alginate impressions were taken at regular intervals following tooth loss and were cast in yellow dental stone. Study models were sectioned longitudinally through the mid-point of both the maxillary incisor socket and the contra-lateral incisor to provide a thin plaster section. Digital photographs were acquired of the edentulous (A1) and dentate (A2) surfaces of this section and image analysis software was employed to quantify the surface area of both A1 and A2. At 3 months postextraction, mean A1 was 15.7% less than mean A2. By 6 months mean A1 had further reduced and was 25.3% less than that of the corresponding dentate alveolus. However, at subsequent time intervals following tooth extraction (>6 months), tissue loss appeared to stabilise with an overall reduction in tissue area remaining at 22%. This reduction in supporting tissue area was found to be highly statistically significant (P = 0.002, anova). Furthermore, girls appeared to have an overall greater degree of tissue loss than boys (P = 0.015). Further research is indicated to explore factors influencing the degree of tissue loss following incisor extraction and the benefit of therapeutic interventions in limiting this resorption. [source] Surgical extrusion of a crown-root fractured immature permanent incisor: 36 month follow-upDENTAL TRAUMATOLOGY, Issue 6 2007Zuhal K Abstract,,, Crown-root fracture is defined as a fracture involving enamel, dentin and pulp and can be classified as either complicated or uncomplicated. The tooth with crown-root fracture presents a lot of problems during coronal restorations and extraction was formerly used in many cases. But loss of a permanent incisor in a young patient may create severe emotional problems and alternative treatment approaches must be considered. This report presents the successful results of a surgical extrusion of a complicated crown-root fractured, immature permanent incisor in a 9-year-old boy. Examination 36 months after the trauma indicated that the treatment had provided functional and esthetic results. [source] Traumatic dental injuries in an urban adolescent population in Tirana, AlbaniaDENTAL TRAUMATOLOGY, Issue 5 2010Dorina Sula Thelen Material & methods: A cross-sectional survey was carried out to acquire epidemiological data about TDI in the permanent incisors of Albanian adolescents. Participants (n = 2789) were adolescents of both genders, aged 16,18 years, attending public high schools in Tirana. Results: The occurrence of TDI in the incisors ranged from 8.9% of 16-year-olds to 10.5% of 18-year-olds. A greater proportion of boys (12.4%) had TDI compared with girls (7.7). The most commonly reported causes were collisions (27.5%) followed by physical leisure activities and sports (mainly cycling and swimming/diving) (14.1%) and falls (13.4%). Of the adolescents affected by TDI, 32% had unmet treatment need because of no or inadequate treatment. Adolescents living in districts with low socio-economic level had significantly more TDI with unmet treatment need than those living in districts with high socio-economic level. Conclusion: The occurrence of TDI among Albanian adolescents was moderate. Adolescents who came from low socio-economic districts had a greater probability of having TDI with unmet treatment need. [source] Prevalence and causes of fractured permanent incisors in 12-year-old suburban Nigerian schoolchildrenDENTAL TRAUMATOLOGY, Issue 3 2009Comfort A. Adekoya-Sofowora A dental trauma cross-sectional survey was carried out through clinical examination of upper and lower permanent incisors and interviews with 415 (212 boys, 203 girls) 12-year-old children attending private and public secondary schools in lle-Ife, in 2004/2005 by one calibrated examiner. Garcia-Godoy's classification was used. The prevalence of traumatic dental injuries was 12.8%. There was no statistical difference in the prevalence between boys and girls P > 0.05. The most common cause of injuries was falls (49.1%), followed by traffic accidents (13.2%), collision against objects or people (11.3%) and misuse of teeth 9.4%. The commonest type of injury was enamel fracture alone (9.9%), followed by enamel-dentine fracture (4.8%). Majority of the accidents occurred at home (60.4%), followed by school (26.4%). The prevalence of traumatic dental injuries was on the increase among suburban Nigerian children in Ile-Ife and it has a potential to be considered an emerging public health problem. [source] An investigation into dentists' management methods of dental trauma to maxillary permanent incisors in Victoria, AustraliaDENTAL TRAUMATOLOGY, Issue 4 2008Thai Yeng To a large extent, the management actions of the dentists involved will determine the clinical outcome and, in turn, these actions will be related to their levels of knowledge. The aim of this study was to investigate dentists' knowledge of managing traumatic injuries to maxillary permanent incisors in children. A self-completion questionnaire containing 19 questions on management methods of treating dental trauma was mailed to 693 dentists in Victoria, Australia. The response rate achieved was 61%. This survey found that some of the respondents had adequate management knowledge for the different types of traumatic injuries, while others did not have the correct information. Approximately half the dentists considered milk as the preferred extraoral storage medium of choice for avulsed teeth and a period of 7,10 days splinting after replantation. A large proportion of dentists showed inadequate knowledge with regard to understanding the biological mechanisms causing replacement root resorption (61%) and external inflammatory root resorption (74%). Overall, the respondents to this survey demonstrated only a moderate level of knowledge in management of traumatic injuries to maxillary permanent incisors in children. Continuing professional development programmes may be a means of improving this deficient knowledge base. [source] The current opinions and use of MTA for apical barrier formation of non-vital immature permanent incisors by consultants in paediatric dentistry in the UKDENTAL TRAUMATOLOGY, Issue 1 2008Gillian Catherine Mooney A semi-structured postal questionnaire was sent to all known consultants in paediatric dentistry in the UK. The response rate was 78.6% (44 of 56). Thity-eight consultants (86.3%) agreed that the use of this material was a good idea with 68.2% having used or arranged for its use in apical barrier formation. Forty-two consultants (95.5%) agreed that reduced number of visits was an advantage to the technique, with only 34.1% agreeing that this procedure was less likely to weaken the tooth and 63.6% agreed that material and equipment costs were a drawback and 50% agreed that lack of available evidence was a disadvantage to its use. The results from this study give an indication of the extent of MTA use by consultant-led services in paediatric dentistry in the UK and highlights the need for a multi-centre randomised controlled clinical trial. [source] Replantation after extended dry storage of avulsed permanent incisors: report of a caseDENTAL TRAUMATOLOGY, Issue 4 2007Funda Kont Cobankara Abstract,,, A 15-year-old boy lost his maxillary right and left central incisor teeth in a bicycle accident. He was referred to our clinic 1 week after the injury. The crown-root integrities of both the teeth were not damaged. Although the teeth were stored under dry conditions for 1 week, reimplantation of the teeth was planned to retain the teeth in the mouth for as long a period as possible because of the patient's age. Following the debridement and sterilization of root surfaces in 2.5% NaOCl, root canals were prepared and filled with calcium hydroxide. Then, about 2 mm of the apexes were resected to ensure that the roots easily seated in the alveolar socket and the prepared cavities in root ends were obturated with the amalgam. The teeth were placed into their respective sockets and splinted temporarily. The root canal therapy was completed 5 weeks later. Ankylosis was observed radiographically after 10 months. The patient is now 23 years old and he is still able to use both the central incisors functionally. However, there is a pink appearance on the cervical buccal surface of left central incisor because of progressive replacement resorption. In this case, the new treatment plan is to perform a permanent restoration with dental implants following the extraction of both teeth. Even though the long-term prognosis is uncertain, this treatment technique has provided an advantage for the patient in his adolescent period by maintaining the height of alveolar bone and making the provision of an aesthetically acceptable permanent restoration at a later age possible. [source] Prevalence of oral trauma in children with bilateral cleftsDENTAL TRAUMATOLOGY, Issue 1 2005Juliana Yassue Barbosa Da Silva Abstract,,, The main object of this study is to analyze the prevalence of oral trauma in subjects with complete bilateral clefts, with anterior projection of the premaxilla. A total of 106 children aging 6 months to 9 years were analyzed. The caretakers answered a specific questionnaire, in order to report the presence or absence of trauma to the soft and/or hard tissues of the child's mouth. Whenever there was a history of trauma, the patients were submitted to clinical examination. The prevalence of oral trauma was 53%, being 91% of soft tissue lesions, 8.9% of avulsion, 7% of luxation and 1.8% of intrusion. For the males, the prevalence was 56% and for the females it was 47%, with no statistical significance. Regarding the following aspects:period of time spent with the parents and at school, and presence or absence of siblings, no statistical difference could be found. Among the traumatized individuals, 80% aged less than 3 years by the moment of the trauma, 89% suffered the trauma at home, 75% presented lesions in the soft tissue at the premaxilla, 16% in the maxillary incisors, and 8.9% presented lesions in both structures. It was noticed that 45% of the permanent incisors that succeeded the traumatized deciduous teeth presented alterations, being 48% of structure and 52% of structure and position. The prevalence of trauma in this sample was superior to that observed in the literature, without any positive associations between the evaluated aspects. These results suggest that the projection of the premaxilla brings about a higher risk of oral trauma around this area. [source] Healing of 400 intra-alveolar root fractures.DENTAL TRAUMATOLOGY, Issue 4 2004Abstract,,, This is the second part of a retrospective study of 400 root-fractured permanent incisors. In this article, the effect of various treatment procedures is analyzed. Treatment delay, i.e. treatment later than 24 h after injury, did not change the root fracture healing pattern, healing with hard tissue between fragments (HH1), interposition of bone and/or periodontal ligament (PDL) or pulp necrosis (NEC). When initial displacement did not exceed 1 mm, optimal repositioning appeared to significantly enhance both the likelihood of pulpal healing and hard tissue repair (HH1). Significant differences in healing were found among the different splinting techniques. The lowest frequency of healing was found with cap splints and the highest with fiberglass or Kevlar® splints. The latter splinting procedure showed almost the same healing result as non-splinting. Comparison between non-splinting and splinting for non-displaced teeth was found to reveal no benefit from splinting. With respect to root fractures with displacement, too few cases were available for analysis. No beneficial effect of splinting periods greater than 4 weeks could be demonstrated. The administration of antibiotics had the paradoxical effect of promoting both HH1 and NEC. No explanation could be found. It was concluded that, optimal repositioning seems to favor healing. Furthermore, the chosen splinting method appears to be related to healing of root fractures, with a preference to pulp healing and healing fusion of fragments to a certain flexibility of the splint and possibly also non-traumatogenic splint application. Splinting for more than 4 weeks was not found to influence the healing pattern. A certain treatment delay (a few days) appears not to result in inferior healing. The role of antibiotics upon fracture healing is questionable. [source] Prevalence and handedness correlates of traumatic injuries to the permanent incisors in 13,17-year-old adolescents in Erzurum, TurkeyDENTAL TRAUMATOLOGY, Issue 5 2003Varol Canakci Abstract ,,,The objectives of the present study were to explore the relationship between dental trauma and handedness, and to assess the prevalence of traumatic injuries to the permanent incisors of 13,17-year-old patients, seeking treatment for various dental conditions in Erzurum, Turkey. A questionnaire focusing on handedness was administered to these patients. Handedness was assessed by the Edinburgh Handedness Inventory (Oldfield, 1971). Hand preference was divided into two classes for convenience in data analysis: (i) right-handers (GSc from 80 to 100); and (ii) left-handers (GSc from ,80 to ,100). This study included the 13,17-year-old group patients who had GSc as described above. Thus, the present study was carried out on 2180 (1252 male and 928 female, with a mean age of 14.9 years) out of 2392 patients. The clinical examinations and radiographic assessments were performed in full-designed dental chairs. Preliminary analysis showed no differences in rates of handedness with respect to sex and age. Overall, 10.4% of the patients were left-handers. A total of 292 (13.4%) of 2180 patients examined had one or more traumatized permanent incisors. The proportion of dental trauma was significantly higher in males than in females, 17.41% in males as compared to 7.97% in females; and ratio of the affected males to females was about 2.18. Sex difference in the prevalence of traumatized permanent incisors was statistically significant (P < 0.001). That is, males had a significantly higher risk of dental trauma than females (P < 0.001; odds ratio: 2.49; 95% confidence interval (CI) 1.88, 3.23). There was a higher level of traumatized permanent incisors among left-handers than among right-handers. 28.3% of left-handers and 11.7% of right-handers had dental trauma. This difference in the prevalence of traumatized permanent incisors for handedness was statistically significant (P < 0.001). Indeed, left-handers had a significantly higher risk on dental trauma than right-handers (P < 0.001; odds ratio: 3.09; 95% CI 2.23, 4.29). The primary causative factor in the occurrence of trauma was the fall (27.7%). Then came violence and fight as the second most frequent cause of trauma (24%), followed by sports injury (18.8%). Trauma resulting from collisions and traffic accidents were accounted as 13.7 and 11.3% of all cases, respectively. The other causes were 4.5%. In conclusion, the present study suggests that left-handed adolescents have more frequent permanent incisor tooth trauma than right-handed adolescents. Left-handedness, therefore, appears to be a risk factor for trauma in 13,17-year-old adolescents. [source] Traumatic injuries to anterior teeth among schoolchildren in MalaysiaDENTAL TRAUMATOLOGY, Issue 4 2001Nik Noriah Nik-Hussein Abstract , Evidence of traumatized permanent incisors was recorded as part of a national oral health survey of schoolchildren in Malaysia. A total of 4085 schoolchildren aged 16 years were examined. The prevalence of injury was 4.1% and it was significantly higher in males than females, with a ratio of 2:1. Almost 75% of the subjects had one tooth affected. Out of a total of 200 fractured teeth, 78.0% involved the maxillary central incisors. A high level of untreated traumatized teeth (89%) was noted. However, of the untreated traumatized teeth, only 9% presented with problems such as discoloration of tooth, sinus or abscess formation. [source] Risk factors for injuries to maxillary permanent incisors and upper lip among schoolchildren in Dar es Salaam, TanzaniaINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2 2009FEBRONIA KOKULENGYA KAHABUKA Background.,, Dental trauma is common among children, and the maxillary permanent central incisors are the most often affected teeth. Aim.,, This study aimed to investigate the risk factors for injury to maxillary permanent incisors and the upper lip among Tanzanian schoolchildren aged 8,14 years. Design.,, A cross-sectional study involving 1119 children. The risk variables investigated included age, gender, lip competence, and overjet. The corresponding proportions of injuries and the relative risk (with 95% confidence interval) were calculated and tested by Fisher's exact test. Logistic regression was applied to ascertain the strength and direction of the association of the risk variables to injuries, and backward selection was used to test significant risk factors. Results.,, About 24% of the children had trauma to maxillary incisors, 45% had incompetent lip whereas 31% had increased overjet. Age, gender, overjet, and lip competence showed significant association with injuries to upper lip and maxillary incisors. Boys had sustained more injuries than girls, with a higher relative risk for luxation injuries. Enamel fracture was associated with overjet combined with lip competence, whereas enamel dentine fracture without pulp involvement was related to gender. Luxation injuries were associated with gender, tooth avulsion with overjet, and lip competence. Injury to the upper lip was associated with age. Conclusion.,, Male gender, increased overjet, and lip incompetence were the main risk factors of getting trauma to maxillary incisors, whereas age was the risk factor for injury to the upper lip. [source] An audit of mineral trioxide aggregate in immature permanent incisorsINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 2008BARBARA CHADWICK No abstract is available for this article. [source] Signs and symptoms from ectodermal organs in young Swedish individuals with oligodontiaINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 5 2006B. BERGENDAL Summary., Objectives., The aim was to assess signs and symptoms from other ectodermal organs in addition to teeth in young individuals with oligodontia and to establish the prevalence of oligodontia. Sample and methods., Children born 1981,94 reported by dental teams in the Public Dental Service to have oligodontia were asked to participate in a clinical study. The examinations comprised a structured interview on symptoms from ectodermal organs, and testing of salivary secretion. Results., One hundred and sixty-two individuals met the inclusion criteria, and 123 individuals (75·9%) participated in the clinical study. Half of the individuals had one to four signs or symptoms from ectodermal organs beside oligodontia. The most common sign was low salivary secretion. Twelve individuals (9·6%) with isolated oligodontia reported impaired function of the sweat glands, hair, or nails. The prevalence of oligodontia was 0·090%. Conclusions., An early identification of individuals with oligodontia can be made in a majority of cases by checking that all permanent incisors have erupted at the age of 8 years. The validity in asking individuals about normal and abnormal function of ectodermal organs was found to be low. This indicates that there is a strong need to establish routine clinical criteria for dysplasia of ectodermal organs. [source] A study into dentists' knowledge of the treatment of traumatic injuries to young permanent incisorsINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 1 2005M. N. KOSTOPOULOU Summary. Objective., The aims of this study were to evaluate dentists' knowledge of the emergency treatment of traumatic injuries to young permanent incisors, and to investigate barriers to treatment. Design., A closed-ended questionnaire was sent to 1023 general dental practitioners (GDPs) and community dental officers (CDOs) in West/North Yorkshire and Humberside, UK. Methods., The questionnaire comprised 17 questions. Six questions asked for general information about the participants (i.e. profession, age, gender, year of graduation, training or education on dental trauma, and willingness to provide emergency care), 10 were relevant to the emergency treatment of crown fractures, root fractures, luxation and avulsion injuries, and the last question queried any perceived barriers to treatment. Results., Seven hundred and twenty-four questionnaires were returned, a response rate of 71%, and these indicated that dentists' knowledge of the emergency treatment of dentoalveolar trauma in children was inadequate. The CDOs were significantly more knowledgeable than the GDPs, as were younger and more recently graduated dentists compared with older ones. The GDPs regarded the difficulty of treating children and the inadequate fees of the UK National Health Service as important barriers to treatment. Dentists who attended continuing dental education courses on dental traumatology had a more thorough knowledge than those who did not. Conclusion., Overall, the dentists' knowledge of the emergency treatment of dentoalveolar trauma in children was inadequate. Greater emphasis on undergraduate and postgraduate education in this area is indicated. [source] Avulsed permanent incisors: knowledge and attitudes of primary school teachers with regard to emergency managementINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 5 2001C. Blakytny Summary. Objectives. This study was designed to examine the knowledge and attitudes of primary school teachers with regard to the emergency management of avulsed permanent incisors. Design. Data were collected by self-administered questionnaire. Setting. The study was conducted in primary schools lying within a 2-mile radius of the University Dental Hospital, Cardiff. Sample and methods. A total of 388 teachers in 31 participating schools were asked to complete a questionnaire, which was subsequently collected by two of the authors (CS and AT). Results. Two hundred and seventy-four teachers returned completed questionnaires, a response rate of 70·6%. One hundred and eighty-one respondents (60·1%) had received no advice about the emergency management of dental avulsion. Of the 133 teachers (48·5%) who possessed a first aid certificate, 39 (29·3%) had been given relevant advice as part of this training. Less than one-third of respondents (85 (31%)) cited an optimum extra-oral time of 30 min or less, with only 43 (15·7%) considering that this should be 10 min or less. However, 125 (45·6%) knew milk to be the best transport medium. Two hundred and four teachers (74·5%) stated that they would not be prepared to replant an avulsed tooth themselves, 133 (80%) basing this decision on lack of expertise and training. Two hundred and sixty-two teachers (95·6%) expressed a desire for further information. Conclusions. The majority of respondents possessed, at best, rudimentary knowledge of the emergency management of dental avulsion. Teachers, and other individuals who supervise children in schools, should receive simple instruction in dental first aid. [source] Simultaneous occurrence of unusual odontodysplasia and oligodontia in the permanent dentition: report of a caseINTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 4 2000T. Fujiwara Odontodysplasia is an uncommon clinicopathological condition with a variety of expressions. Although it is generally recognized as a localized disorder of dental tissue, its aetiology has not yet been well explained. In the present case, odontodysplasia with oligodontia in the permanent dentition is reported. The patient was in good health with normal stature and no other physical abnormalities. His parents and siblings were dentally and medically normal. The primary teeth appeared to be normal except for the primary second molars, where the enamel was malformed. However, the permanent incisors that had erupted into the oral cavity showed rough and hypoplastic enamel. An orthopantomogram showed 17 congenitally missing permanent teeth and malformation of the other 11 permanent teeth and tooth-germs. Because these findings were caused by developmental disturbances of both the mesodermal and ectodermal dental components, we diagnosed the present case as odontodysplasia accompanied by oligodontia in the permanent dentition. [source] Long-term prognosis of crown-fractured permanent incisors.INTERNATIONAL JOURNAL OF PAEDIATRIC DENTISTRY, Issue 3 2000The effect of stage of root development, associated luxation injury Objectives. The aim of the present study was to investigate pulp healing responses following crown fracture with and without pulp exposure as well as with and without associated luxation injury and in relation to stage of root development. Patient material and methods. The long-term prognosis was examined for 455 permanent teeth with crown fractures, 352 (246 with associated luxation injury) without pulpal involvement and 103 (69 with associated luxation injury) with pulp exposures. Initial treatment for all patients was provided by on-call oral surgeons at the emergency service, University Hospital (Rigshospitalet), Copenhagen. In fractures without pulpal involvement, dentin was covered by a hard-setting calcium hydroxide cement (Dycal®), marginal enamel acid-etched (phosphoric acid gel), then covered with a temporary crown and bridge material. In the case of pulp exposure, pulp capping or partial pulpotomy was performed. Thereafter treatment was identical to the first group. Patients were then referred to their own dentist for resin composite restoration. Results. Patients were monitored for normal pulp healing or healing complications for up to 17 years after injury (x = 2·3 years, range 0·2,17·0 years, SD + 2·7). Pulp healing was registered and classified into pulp survival with no radiographic change (PS), pulp canal obliteration (PCO) and pulp necrosis (PN). Healing was related to the following clinical factors: stage of root development at the time of injury, associated damage to the periodontium at time of injury (luxation) and time interval from injury until initial treatment. Crown fractures with or without pulp exposure and no concomitant luxation injury showed PS in 99%, PCO in 1% and PN in 0%. Crown fractures with concomitant luxation showed PS in 70%, PCO in 5% and PN in 25%. An associated damage to the periodontal ligament significantly increased the likelihood of pulp necrosis from 0% to 28% (P < 0·001) in teeth with only enamel and dentin exposure and from 0% to 14% (P < 0·001) in teeth with pulp exposure. Conclusions. In the case of concomitant luxation injuries, the stage of root development played an important role in the risk of pulp necrosis after crown fracture. However, the primary factor related to pulp healing events after crown fracture appears to be compromised pulp circulation due to concomitant luxation injuries. [source] Confocal Examination of Subsurface Cracking in Ceramic MaterialsJOURNAL OF PROSTHODONTICS, Issue 7 2009MMedSc, Maged K. Etman DDS Abstract Purpose: The original ceramic surface finish and its microstructure may have an effect on crack propagation. The purpose of this study was to investigate the relation between crack propagation and ceramic microstructure following cyclic fatigue loading, and to qualitatively evaluate and quantitatively measure the surface and subsurface crack depths of three types of ceramic restorations with different microstructures using a Confocal Laser Scanning Microscope (CLSM) and Scanning Electron Microscope (SEM). Materials and Methods: Twenty (8 × 4 × 2 mm3) blocks of AllCeram (AC), experimental ceramic (EC, IPS e.max Press), and Sensation SL (SSL) were prepared, ten glazed and ten polished of each material. Sixty antagonist enamel specimens were made from the labial surfaces of permanent incisors. The ceramic abraders were attached to a wear machine, so that each enamel specimen presented at 45 degrees to the vertical movement of the abraders, and immersed in artificial saliva. Wear was induced for 80K cycles at 60 cycles/min with a load of 40 N and 2-mm horizontal deflection. The specimens were examined for cracks at baseline, 5K, 10K, 20K, 40K, and 80K cycles. Results: Twenty- to 30-,m deep subsurface cracking appeared in SSL, with 8 to 10 ,m in AC, and 7 ,m close to the margin of the wear facets in glazed EC after 5K cycles. The EC showed no cracks with increasing wear cycles. Seventy-,m deep subsurface cracks were detected in SSL and 45 ,m in AC after 80K cycles. Statistically, there was significant difference among the three materials (p < 0.05). Bonferroni multiple comparison of means test confirmed the ANOVA test and showed that there was no statistical difference (p > 0.05) in crack depth within the same ceramic material with different surface finishes. Conclusions: The ceramic materials with different microstructures showed different patterns of subsurface cracking. [source] Dental wear, wear rate, and dental disease in the African apesAMERICAN JOURNAL OF PRIMATOLOGY, Issue 6 2010Alison A. Elgart Abstract The African apes possess thinner enamel than do other hominoids, and a certain amount of dentin exposure may be advantageous in the processing of tough diets eaten by Gorilla. Dental wear (attrition plus abrasion) that erodes the enamel exposes the underlying dentin and creates additional cutting edges at the dentin-enamel junction. Hypothetically, efficiency of food processing increases with junction formation until an optimal amount is reached, but excessive wear hinders efficient food processing and may lead to sickness, reduced fecundity, and death. Occlusal surfaces of molars and incisors in three populations each of Gorilla and Pan were videotaped and digitized. The quantity of incisal and molar occlusal dental wear and the lengths of dentin,enamel junctions were measured in 220 adult and 31 juvenile gorilla and chimpanzee skulls. Rates of dental wear were calculated in juveniles by scoring the degree of wear between adjacent molars M1 and M2. Differences were compared by principal (major) axis analysis. ANOVAs compared means of wear amounts. Pearson correlation coefficients were calculated to compare the relationship between molar wear and incidence of dental disease. Results indicate that quantities of wear are significantly greater in permanent incisors and molars and juvenile molars of gorillas compared to chimpanzees. The lengths of dentin,enamel junctions were predominantly suboptimal. Western lowland gorillas have the highest quantities of wear and the most molars with suboptimal wear. The highest rates of wear are seen in Pan paniscus and Pan t. troglodytes, and the lowest rates are found in P.t. schweinfurthii and G. g. graueri. Among gorillas, G. b. beringei have the highest rates but low amounts of wear. Coefficients between wear and dental disease were low, but significant when all teeth were combined. Gorilla teeth are durable, and wear does not lead to mechanical senescence in this sample. Am. J. Primatol. 72:481,491, 2010. © 2010 Wiley-Liss, Inc. [source] | ||||||||||