Tooth loss and coronal caries of elderly residents in Singapore.
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Age Factors↗
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Pathologic study of periapical lesions 1. Periapical granulomas: clinical, histopathologic and immunohistopathologic studies.
Seventy periapical granulomas were histopathologically examined. They were divided into four types: exudative, granulomatous, granulo-fibrous, and fibrous types. Clinicopathologically, those having marked lymphocytic infiltration were found more frequently in cases having had endodontic treatment; further, the size of a radiolucent area did not exceed that of the involved tooth crown. In contrast, a predominant plasma cell infiltrate was more frequent in cases with open pulp chambers (no treatment). In those cases, the radiolucent area was larger than the crown. Foci with very large radiolucent areas were often of the exudative type. Epithelial proliferation was more frequent in cases without treatment. These findings indicate that endodontic treatment not only stops invasion of injurious factors but also proliferation of epithelium. Furthermore, in frozen sections of 26 granulomas, IgE-containing cells and IgG and C3 fluorescence in the connective tissue were often observed. It appears that IgE-mediated reaction and antigen-antibody complexes may play a role in periapical pathosis.
Adolescent↗
Enamel apposition rate and the prism periodicity in human teeth.
A method is presented which allows the average daily rate of enamel apposition to be estimated based on measurements of the length of prisms in longitudinal ground sections, and on available data for the time of formation of the tooth crown. The method was applied on 21 sections of human maxillary premolars. The reproducibility of the method was satisfactory, the error of measurement being in the order of 3.8%. After corrections having been made for the deviation of prisms from a radial direction, the average daily rate of enamel apposition along the prisms for any maxillary premolar was estimated to be within a range of from 2.0 to 6.1 microns, while a more probable rate would be 2.7-4.6 microns. These results are in agreement with experimental data, and are also compatible with the observed cross-striation prism periodicity. The present study supports the theory that there exists a relationship between the prism periodicity and a 24-h rhythm in enamel apposition in human teeth.
Ameloblasts↗
Pulp calcifications in traumatized primary incisors. A morphological and inductive analysis study.
The purpose of this study was to investigate histopathological changes in primary teeth following trauma, and to look for possible correlations between the morphology of pulpal calcification and clinical findings. The material consisted of 123 primary teeth from 98 Danish children aged 9-108 months (mean age 33.5 +/- 19.7 months) at the time of injury. The specimens were analyzed by means of light and scanning and transmission electron microscopy. Data from the clinical investigation and from predetermined ranked parameters from the histological analysis were processed in a computerized inductive analysis program. The results, describing patterns of co-variation, are presented as a decision tree. The most common diagnosis was intrusion luxation (54%). In 41% of all teeth, the degree of obliteration was less than 1/4 of the pulpal lumen. In most cases (79%), no denticles were visible. When present, 80% of the denticles had a bone-like appearance. Tissues occluding the pulpal lumen were either dentin-like (49%), bone-like (19%), or fibrotic (9%). It could be concluded that these varying responses could not be correlated with explicit clinical diagnoses. However, in certain combinations, histological parameters could be correlated to clinical findings.
Bone and Bones↗
Cell proliferation in developing human dental pulp. A combined flow cytometric and immunohistochemical study.
Information concerning cell proliferation and differentiation in dental pulp may be important to understand tooth response to exogenous stimuli. Since few data concerning human dental pulp are available, we have investigated the growth fraction and the localization of proliferating cells in pulp tissue of third molars of young adult human males and females, using flow cytometry and immunohistochemistry. Flow cytometric analysis demonstrates a low proliferative activity of pulp tissue that appears to be confined to radicular pulp, as revealed by immunohistochemical detection of proliferating cells. No polyploid or aneuploid cell populations could be identified, and G2-blocked cells, if any, represented a negligible cell population. Odontoblasts, cells of the sub-odontoblastic layer, and cells of coronal pulp were found to be not proliferating under normal conditions. These data provide the basis for future investigations on proliferative activity and regenerative potentiality of human pulp cells in experimental and clinical situations.
Adolescent↗
Can internal stresses explain the fracture resistance of cusp-replacing composite restorations?
The aim of this study was to explore and compare the results of occlusal load application to cusp-replacing composite restorations, studied by means of finite element (FE) analysis and in vitro load tests. A three-dimensional (3D) FE model was created with a set up similar to an in vitro load test that assessed the fatigue resistance of upper premolars with buccal cusp-replacing resin composite restorations. Occlusal load was applied to two geometries (with and without palatal cuspal coverage), and the tooth-restoration interface and composite material stresses were calculated. Subsequently, safety factors were calculated by dividing the material strength values by the obtained stresses. The highest safety factors were observed for the restorations with cuspal coverage. This was consistent with the load test, in which cuspal coverage led to higher fracture resistance. Furthermore, the FE analysis predicted that failure of the tooth-restoration interface is more likely than failure of the composite material. Correspondingly, the load test showed predominantly adhesive failures of the restorations. Although the described test methods did not lead to a complete understanding of the failure mechanism, it can be concluded that the FE analysis provides additional information with regard to the differences in fracture behaviour of these types of restorations.
Adhesiveness↗
Fracture resistance of re-attached coronal fragments--influence of different adhesive materials and bevel preparation.
The purpose of this study was to investigate the fracture resistance of re-attached coronal fragments of teeth using different materials and tooth preparations. Seventy-two recently extracted bovine incisors were selected. Eight incisors were maintained without any preparation as a control group. The incisal third of the other teeth was sectioned using a diamond saw. In one group (n = 32), a 2-mm bevel was prepared, whereas in the second group no preparation was made (n = 32). The specimens (beveled and non-beveled) were divided in four groups (n = 8) and re-attached with the following materials: a dual-cured resin cement RelyX ARC (RX); a chemically cured composite Bisfil 2B (B2); a light-cured composite Z250 (Z2); and a one-bottle adhesive Single Bond (SB). The bevel region was restored with adhesive and composite. All materials were used according to manufacturer's directions. A light-curing unit was used to polymerize the materials. Specimens were stored in saline solution for 72 h. De-bonding procedures were performed in a testing machine with cross-head speed of 0.6 mm min(-1). The load was applied in the incisal third. The resistance to fracture for control group was 70 (7) kg. The fracture resistance for non-beveled and beveled specimens were: SB, 3.3 (2.4) and 17.0 (4.1); RX, 11.5 (3.0) and 16.3 (3.1); Z2, 14.4 (4.2) and 20.5 (1.7); and B2, 19.5 (3.5) and 32.5 (7.4) kg. Analysis of variance (anova) and Fisher's protected least significant difference (PLSD) test disclosed significant influence for materials and cavity designs (P = 0.001). The highest failure loads were obtained with the B2 group and then with the Z2 with either bevel or non-bevel. RX produced lower failure loads than the restorative composites. The lowest failure load was obtained with SB in the non-beveled group. No technique studied was able to attain the fracture resistance of the control group and both materials and tooth preparation influenced the fracture resistance.
Analysis of Variance↗
An in vitro study of the efficacy of mouthguard protection for dentoalveolar injuries in deciduous and mixed dentitions.
Sports-related dental trauma remains a risk for children and adolescents. Although mouthguards provide protection, up to 25% of dentoalveolar injuries can occur with a mouthguard in place. This study examined the effect of mouthguard protection in an in vitro model. A total of 97 sheep mandibular segments with incisors at four developmental stages (early deciduous, ED, n = 37; middle deciduous, MD, n = 20; late deciduous, LD, n = 18; mixed dentition, PD, n = 22) was used. Customised pressure formed mouthguards (MG) provided protection from trauma produced by a servohydraulic materials testing machine to test incisors. Injuries were examined clinically, radiographically and by dissection. Mean forces required to produce dentoalveolar injury were significantly greater in test (with MG) teeth than control (no MG) teeth. Mean forces to produce injury in test teeth decreased with resorbing root lengths. Deciduous incisors differed in injury type: subluxations and horizontal root fractures predominated in test teeth; lateral luxations and horizontal root fractures in control teeth. Predominant injuries in test and control permanent incisors were enamel infractions and subluxations. The magnitude of lateral luxation measurements of individual teeth was reduced significantly by mouthguard protection in both deciduous and permanent dentitions. The mouthguard tended to increase the mobility of the teeth it encompassed and, in some instances, promoted dentoalveolar injury of adjacent teeth.
Alveolar Process↗
An evaluation of after-office-hour dental trauma in Singapore.
The purpose of this study was to assess the post-traumatic sequelae and treatment outcome and the corresponding prognostic factors at the initial emergency visit. Over a 5-year period, the authors collected case records from 129 dental trauma patients. These patients had been referred subsequent to receiving emergency treatment after office hours at the Accident and Emergency Department of Singapore General Hospital. After the exclusion of 31 cases with concomitant fracture of maxilla and/or mandible and cases with insufficient documentation, the final study sample consisted of 98 patients (41 males, 57 females) who had sustained injuries to 264 permanent teeth. The main cause of dental trauma was falls (56%), and the main type of injuries was periodontal tissue injuries with or without concomitant injuries to hard tissue, including root fracture (73%). For the final evaluation, teeth with insufficient recall period were excluded before univariate and multivariate stepwise logistic regression analysis. It was found that for 100 teeth with luxation type of injuries, the presence of concomitant hard tissue injuries retained prognostic significance for pulpal outcome (p < 0.001) after adjusting for severity of luxation, while the severity of luxation was the only significant factor for periodontal outcome (p < 0.001). For 34 avulsed teeth, the stage of root development was the major factor associated with the pulpal outcome (p = 0.003), while extra-alveolar storage media were found to be significantly related to the periodontal outcome (p < 0.001). For 72 teeth with hard tissue injuries, first-visit interval played a significant role in the outcome (p = 0.03). Although the sample size in the root fracture group was too small for such statistical analysis, the results indicated that patient education on dental trauma was an important factor. Thorough standardized documentation was also recommended to facilitate optimal follow-up management and future research as well as medico-legal purposes.
Adolescent↗
Adhesive bonding of fragmented anterior teeth.
This in vitro study investigated the fracture strengths of fractured incisors after reattachment to the remaining tooth structure, using either Gluma dentin-bonding agent together with 1 of 13 different experimental resins or 1 of the following dentin-bonding agents: Gluma+ (experimental modification of Gluma), Panavia21, ScotchBond1 (SingleBond), All-Bond2, Dentastic, SuperBond, Prime&Bond 2.1. No significant differences were found in the experiments with various experimental resins. The fracture strength of teeth rebonded with Gluma, All-Bond2, Dentastic, SuperBond or Prime&Bond 2.1 showed mean fracture strengths in the range of 8.7-11.2 MPa, which were significantly different in all cases from that of intact teeth (16.3 MPa). Teeth bonded with Gluma+, Panavia21 or ScotchBond1 (SingleBond) showed mean fracture strengths of 15.5, 14.6, and 14.2 MPa, respectively. These fracture strengths were not significantly different from that of intact teeth.
Animals↗
Dens invaginatus: treatment choices.
Dens invaginatus is a well-known and well-established anomaly of development. Because it appears in various and complex forms, its diagnosis and treatment may be difficult. This paper presents different options based on anomaly variations, taking into consideration clinical and radiographic aspects as well as other criteria for treatment planning.
Apicoectomy↗
Factors affecting coronal fracture of anterior teeth in North Jordanian children.
The aims of this study were to investigate the incidence of coronal fracture of the anterior teeth in North Jordanian schoolchildren and to study the main predisposing factors and the factors that may affect the severity of this fracture. A study group (958) comprising schoolchildren aged 13-15 years was chosen by a simple random method from five geographical areas in Irbid Governate, Jordan. All children completed a questionnaire related to history of trauma to their anterior teeth before they had a clinical examination for lip competence, lip line and amount of fracture. Overjet was recorded from a study cast made for each student. Statistical analysis was performed using chi-square test. The results showed a prevalence of 11% of coronal fracture with female-male ratio of 1:1. An increase in the overjet more than 3 mm doubled the incidence of coronal fracture while overjet more than 6 mm increased the incidence fourfold. There was higher incidence of coronal fracture associated with lip incompetence and low lip line (P <0.01). The severity of fracture increased in children with a larger overjet (P <0.001). It was concluded that overjet, lip competence and lip line were important predisposing factors to coronal fracture of the anterior teeth while the severity of the fracture was mainly determined by overjet.
Adolescent↗
Healing of 400 intra-alveolar root fractures. 1. Effect of pre-injury and injury factors such as sex, age, stage of root development, fracture type, location of fracture and severity of dislocation.
This retrospective study consisted of 400 root-fractured, splinted or non-splinted incisors in young individuals aged 7-17 years (mean = 11.5 +/- 2.7 SD) who were treated in the period 1959-1995 at the Department of Pediatric Dentistry, Eastman Dental Institute, Stockholm. Four hundred of these root fractures were diagnosed at the time of injury; and 344 teeth were splinted with either cap-splints, orthodontic appliances, bonded metal wires, proximal bonding with composite resin or bonding with a Kevlar or glass fiber splint. In 56 teeth, no splinting was carried out for various reasons. In the present study, only pre-injury and injury factors were analyzed. In a second study, treatment variables will be analyzed. The average observation period was 3.1 years +/- 2.6 SD. The clinical and radiographic findings showed that 120 teeth out of 400 teeth (30%) had healed by hard tissue fusion of the fragments. Interposition of periodontal ligament (PDL) and bone between fragments was found in 22 teeth (5%), whereas interposition of PDL alone was found in 170 teeth (43%). Finally, non-healing, with pulp necrosis and inflammatory changes between fragments, was seen in 88 teeth (22%). In a univariate and multivariate stratified analysis, a series of clinical factors were analyzed for their relation to the healing outcome with respect to pulp healing vs. pulp necrosis and type of healing (hard tissue vs. interposition of bone and/or PDL or pulp necrosis). Young age, immature root formation and positive pulp sensibility at the time of injury were found to be significantly and positively related to both pulpal healing and hard tissue repair of the fracture. The same applied to concussion or subluxation (i.e. no displacement) of the coronal fragment compared to extrusion or lateral luxation (i.e. displacement). Furthermore, no mobility vs. mobility of the coronal fragment. Healing was progressively worsened with increased millimeter diastasis between fragments. Sex was a significant factor, as girls showed more frequent hard tissue healing than boys. This relationship could possibly be explained by the fact that girls experienced trauma at an earlier age (i.e. with more immature root formation) and their traumas were of a less severe nature. Thus, the pre-injury or injury factors which had the greatest influence upon healing (i.e. whether hard tissue fusion or pulp necrosis) were: age, stage of root development (i.e. the size of the pulpal lumen at the fracture site) and mobility of the coronal fragment, dislocation of the coronal fragment and diastasis between fragments (i.e. rupture or stretching of the pulp at the fracture site).
Adolescent↗
Development of clinical and radiographic signs associated with dark discolored primary incisors following traumatic injuries: a prospective controlled study.
The purpose was to evaluate late complications of asymptomatic traumatized primary incisors with dark coronal discoloration. The clinical and radiographic signs of 97 teeth of the study group were recorded along a follow-up period that ranged between 12 and 75 months (mean >36 months). Children's age at time of injury ranged between 18 and 72 months (mean 40). The control group consisted of 102 non-discolored maxillary primary central incisors in 51 children older than 54 months with no history of dental trauma. In 50 teeth (52%) the color faded or became yellowish and in 47 (48%) it remained dark. Clinical signs of infection, that were diagnosed 5-58 months after the injury, were associated significantly more with dark than yellowish hues (83 and 17%, respectively). Teeth that had changed their color to become yellow presented more PCO than teeth with black/gray/brown coronal discoloration (78 and 6%, respectively). Arrest of dentine apposition was found in 15 teeth, one had yellow coronal discoloration and the remaining 14 had a dark shade. Eleven teeth showed inflammatory root resorption all with dark discoloration. Two atypical types of root resorption were observed: a surface resorption restricted to the lateral aspects of the apical half of the root while the root length remained unchanged and in the other expansion of the follicle of the permanent successor was observed. Expansion of the dental follicle was observed in 72% of all teeth with no significant difference between the various types of coronal discoloration but only half of the cases were associated with resorption of the root of the primary incisor. The various pathologic findings observed in the study group were either absent or rarely seen in the control group. It can be concluded that more than 50% of the primary incisors that retain their dark coronal discoloration acquired after dental injuries remain clinically asymptomatic till the eruption of the permanent successor even if they present accelerated root resorption. Asymptomatic traumatized primary incisors that retain their dark coronal discoloration may develop a sinus tract and inflammatory root resorption years after the injury. There is still a dilemma: which treatment is better for dark discolored primary incisors: early endodontic treatment or follow-up with the risk of development of infection and root resorption that may require extraction?
Bacterial Infections↗
Multiple dental fractures following tongue barbell placement: a case report.
The number of adolescents and young adults undergoing intra-oral piercing, is increasing worldwide. There have been several case reports documenting oral and systemic complications of this practice. These include damage to the dentition, gingivae, infection, speech impediments and nerve damage. The case presented here draws attention to the possibility of multiple tooth fracture as a result of trauma incurred from a barbell inserted into the tongue.
Adolescent↗
Severe trauma in the primary dentition--diagnosis and treatment of sequelae in permanent dentition.
A 2-year 6-month male presented after an intrusive injury sustained at 15 months of age. Intra-oral radiographs showed coronal dilaceration of the germ of the permanent central incisor and the presence of a calcified tissue mass in the area of the trauma which was identified after surgical removal as the permanent upper left lateral incisor. Immediate treatment and long-term options are discussed.
Child, Preschool↗
Exposed human pulp caused by trauma and/or caries in primary dentition: a histological evaluation.
The aim of this study was to compare the pulpal reactions after exposure due to trauma and/or caries and to suggest the appropriate treatment options for the management of pulp, in the light of the histological findings in the primary teeth. Fifteen primary maxillary incisors with pulpal exposure were examined with light microscope in a blind study. After the histological evaluation, teeth were divided into three groups for the etiological factors due to the exposure according to the patient's files: trauma group, caries group and caries and trauma group. The inflammatory infiltration was diminished from the pulp chamber towards the apical third of the root canal in all of the examined teeth. Teeth in the trauma group presented fewer inflammatory cells in the root canal in comparison with other groups. It was concluded that the teeth with traumatic pulp exposure were considered as more likely to respond positively to pulpotomy technique. Pulpectomy or extraction seemed to be indicated for the decayed or decayed and traumatically injured teeth.
Child, Preschool↗
External resorption presenting as an intracoronal radiolucent lesion in a pre-eruptive tooth.
A large intracoronal radiolucent lesion in an unerupted permanent molar was found during the routine assessment of a young male Caucasian prior to orthodontic treatment. The tooth was extracted. Histological examination indicated the lesion was caused by external resorption. The defect extended widely into the enamel and dentine, and was repaired in part by bone. The pulp chamber was not involved. The aetiology of these lesions is often obscure but in this case it appeared to have originated in the floor of two developmental pits on the occlusal surface of the tooth.
Child↗