Effect of treatment delay upon pulp and periodontal healing of traumatic dental injuries -- a review article

Based on an analysis of the literature concerning parameters influencing the prognosis of traumatic dental injuries, few studies were found to have examined possible relationships between treatment delay and pulpal and periodontal ligament healing complications. It has been commonly accepted that all injuries should be treated on an emergency basis, for the comfort of the patient and also to reduce wound healing complications. For practical and especially economic reasons, various approaches can be selected to fulfill such a demand, such as acute treatment (i.e. within a few hours), subacute (i.e. within the first 24 h), and delayed (i.e. after the first 24 h). In this survey the consequences of treatment delay on pulpal and periodontal healing have been analyzed for the various dental trauma groups. Applying such a treatment approach to the various types of injuries, the following treatment guidelines can be recommended, based on our present rather limited knowledge of the effect of treatment delay upon wound healing. Crown and crown/root fractures: Subacute or delayed approach. Root fractures: Acute or subacute approach. Alveolar fractures: Acute approach (evidence however questionable). Concussion and subluxation: Subacute approach. Extrusion and lateral luxation: Acute or subacute approach (evidence however questionable). Intrusion: Subacute approach (evidence however questionable). Avulsion: If the tooth is not replanted at the time of injury, acute approach; otherwise subacute. Primary tooth injury: Subacute approach, unless the primary tooth is displaced into the follicle of the permanent tooth or occlusal problems are present; in the latter instances, an acute approach should be chosen. These treatment guidelines are based on very limited evidence from the literature and should be revised as soon as more evidence about the effect of treatment delay becomes available.

Guidelines for the management of traumatic dental injuries. I. Fractures and luxations of permanent teeth

Crown fractures and luxations occur most frequently of all dental injuries. An appropriate treatment plan after an injury is important for a good prognosis. Guidelines are useful for delivering the best care possible in an efficient manner. The International Association of Dental Traumatology (IADT) has developed a consensus statement after a review of the dental literature and group discussions. Experienced researchers and clinicians from various specialties were included in the group. In cases where the data did not appear conclusive, recommendations were based on the consensus opinion of the IADT board members. The guidelines represent the current best evidence, based on literature research and professional opinion. In this first article of three, the IADT Guidelines for management of fractures and luxations of permanent teeth will be presented.

Crown fractures in the permanent dentition: pulpal and restorative considerations

Crown fractures account for the highest percentage of all traumatic injuries in the permanent dentition. This review paper will discuss the different types of crown fracture, from the uncomplicated to complicated, including crown-root fractures. It will focus on two different aspects: the pulp, with an attempt to correlate epidemiological, experimental, histopathological and clinical studies, so that the clinician can better understand the underlying processes accounting for success or failure to maintain pulp vitality. Also, we will consider the restoration: knowledge about bonding to dentin and new material is evolving extremely quickly making it difficult for the clinician to keep up with the developments. If handled properly, prognosis of the pulp, after traumatic crown fracture, is good. Prognosis of the restoration has also improved considerably over the last few years, and it appears that this trend will continue in the future.

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).

Traumatic dental injuries in Brazilian preschool children

The purpose of this study was to determine the prevalence and distribution of traumatic injuries to primary anterior teeth in children from zero to 6 years old, all attendees in 28 public nursery schools in Canoas (Brazil). A total of 1545 boys and girls participated in the study. The children were clinically examined for signs of trauma according to Andreasen's classification. Traumatic injuries were identified in 35.5% of children. The largest percentage of injuries was demonstrated by 3-4-year-old child, with no significant difference between boys and girls. The maxillary central incisor was the most vulnerable to injury, without differences between the right and the left side. Single tooth injury was predominant in all age groups. Crown fractures represented 83% of all traumatic injuries. Our findings emphasize the importance of encouraging parents to visit the dentist with their child at an early stage. Furthermore, parents and educators should be advised about prevention of traumatic injuries and actions to be taken in case of an accident.

Dental injury associated with anesthesia: a report of 161,687 anesthetics given over 14 years

STUDY OBJECTIVE

To determine the frequency, outcomes, and risk factors for dental injury related to anesthesia.

DESIGN

Case-control study.

SETTING

Tertiary-care university hospital.

PATIENTS

Patients who had a perianesthetic dental injury between August of 1989 and December 31, 2003.

MEASUREMENTS

A 1:2 case control study was done to identify the frequency, outcomes, and risk factors for dental injury. Perianesthetic dental injuries were defined as any notable change to the patient's dentition during the perianesthetic period that may or may not have required dental consultation or treatment.

MAIN RESULTS

Seventy-eight patients with perianesthetic dental injury were identified. The incidence of dental injury was one per 2,073 anesthetics. Eighty-six percent of dental injuries were discovered by the anesthesia provider. Maxillary incisors were the most frequently injured teeth. The most commonly reported injuries were enamel fracture, loosened or subluxated teeth, tooth avulsion, and crown or root fracture. Patients with poor dentition or reconstructive work, whose tracheas were moderately difficult or difficult to intubate, were at much higher risk (approximately 20-fold) of dental injury than those with good dentition and found to be easy to intubate. Among those whose tracheas were easy to intubate, patients with poor dentition or reconstructive work were 3.4 times more likely to have dental injuries related to anesthesia.

CONCLUSIONS

Dental injury is one of the most common adverse events reported in association with anesthesia. Risk factors include preexisting poor dentition or reconstructive work and moderately difficult to difficult intubation.

Traumatic intrusion of permanent teeth. Part 3. A clinical study of the effect of treatment variables such as treatment delay, method of repositioning, type of splint, length of splinting and antibiotics on 140 teeth

A prospective study of 140 intruded permanent teeth was examined for the following healing complications: pulp necrosis (PN), root resorption (RR; surface, inflammatory and replacement resorption), and defects in marginal periodontal bone healing (MA). The occurrence of these healing complications was related to various treatment factors such as treatment delay, method of repositioning (i.e. expecting re-eruption, orthodontic reposition and surgical reposition), type of splint (rigid, semirigid and flexible), length of splinting (days) and the use of antibiotics. Treatment delay, i.e. before and after 24 h, had no effect upon healing. Active repositioning in individuals with incomplete root formation (surgical or orthodontic) had a negative effect upon the three healing parameters compared with spontaneous eruption. In teeth with complete root formation and an age of 12-17 no repositioning was still the best treatment in regard to MA. In individuals older than 17 years of age, cases were not anticipated to spontaneously erupt and in these cases, the general choice of treatment was either active orthodontic or surgical repositioning. The former procedure appeared in this treatment scenario to slightly reduce the risk of MA complications. However, this treatment procedure was also found to be more time demanding (an average of 22 consultations for orthodontic repositioning compared with 17 consultations for surgical repositioning). If a surgical repositioning was performed, the type of splint (i.e. flexible, semirigid or rigid) appeared to have no significant effect on the type of healing. The same applied to the length of splinting time (shorter or longer than 6 weeks). No effect of dentin covering procedures for associated crown fractures (enamel-dentin fractures) could be demonstrated. Likewise, antibiotics had no apparent effect upon healing. In conclusion, in patients with intruded teeth with incomplete root formation, spontaneous eruption should be expected. In patients with completed root formation and with an age of 12-17 spontaneous eruption can still occur, but must be monitored very carefully. In older patients (i.e. >17 years) with completed root formation, either surgical or orthodontic extrusion should be attempted. The latter procedure appeared to lead to a slight reduction (not significant) in the risk of MA complications. The extent and direction of the intrusion may however favour surgical repositioning.

Traumatic intrusion of permanent teeth. Part 2. A clinical study of the effect of preinjury and injury factors, such as sex, age, stage of root development, tooth location, and extent of injury including number of intruded teeth on 140 intruded permanent teeth

A prospective study of 140 intruded permanent teeth was done to evaluate the following healing complications: pulp necrosis (PN), root resorption (surface, inflammatory and replacement resorption) (RR) and defects in marginal periodontal healing (MA). These complications were related to various preinjury and injury factors. Age appeared to be related to all three healing complications in that patients younger than 12 years had the lowest complication rate. Stage of root formation at the time of the injury was very strongly related to PN and MA, with immature root formation (i.e. incomplete root formation or completed root formation with wide open apex) having better prognosis than more mature root development. Lateral incisors showed significantly more defects in MA, a finding possibly explained by the observation that lateral incisors were more often involved in multiple intrusions compared to other teeth and noting that multiple intrusions had a significantly higher frequency of MA. An associated crown fracture with exposed dentin resulted in more frequent PN, a finding possibly related to bacterial invasion through dentinal tubules into an ischemic pulp. The presence of a gingival laceration added to both PN and MA. The extent of intrusion (in mm) showed some relation to both RR with intrusion 1-3 mm having the lowest frequency of RR, whereas PN and MA showed no significant relation to the extent of intrusion. Finally, multiple adjacent intruded teeth were more frequently involved in a significantly greater loss of interproximal marginal bone (MA) than single intrusions. In conclusion, the relationship between healing complications and preinjury and injury factors could generally be explained by better healing possibilities in teeth with immature root formation. A possible explanation for that could be the softer bone surrounding the tooth, whereby trauma to the periodontium might be diminished.

Traumatized permanent teeth in Brazilian children assisted at the Federal University of Santa Catarina, Brazil

The goal of this study was to determine factors related to the occurrence of dental trauma in permanent teeth of children assisted at the Pediatric Dentistry Clinic of the Federal University of Santa Catarina (UFSC) Florianópolis, Brazil. During a period of 18 months, 36 children between 7 and 12 years of age had 72 traumatized teeth treated. The children were all assisted by one professional, a dentist working as a trainee of the Pediatric Dentistry Clinic. The occurrence of trauma was higher in male patients (61.3%) and in children between 8 and 9 years old with an average age of mean=9.4 years. In the group assisted, 63.9% of the children had more than one traumatized tooth and trauma reoccurred 19.4% of the time. The maxillary anterior teeth represented 96.1% of the cases and the central incisor teeth were the most affected. Both sides of the mouth had approximately the same number of traumas. Fractures were more frequent (51.4%) than luxations (48.6%). Enamel/dentin crown fractures represented 51.4% of the total traumatized teeth. Falls were the main cause of trauma (83.3%). A dental professional assisted 36.1% of the children in some way during the first 24 h after the incident. The study concluded that the permanent dentition is mostly affected by crown fractures that occur especially on maxillary central incisor teeth in patients between 8 and 9 years of age. The major etiological factor is falls that affected more than one tooth. Re-occurrence of trauma is fairly common.

Long-term prognosis of crown-fractured permanent incisors. The effect of stage of root development and 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.

Traumatic intrusion of permanent teeth. Part 1. An epidemiological study of 216 intruded permanent teeth

An epidemiological study of traumatic intrusion of permanent teeth was performed on 216 teeth in 151 patients treated over a 50-year period at a major trauma center in Denmark (Copenhagen). This analysis showed that intrusion of permanent teeth was of rare injury only affecting 1.9% of traumatic injuries involving permanent teeth. The main etiologic factor appeared to be falling which resulted in axial impacts on maxillary or mandibular teeth. The most common injury patterns were intrusion without additional injuries (33.5%) and intrusion with crown fractures (60.5%). A few cases were combinations of intrusion and either crown/root-fractures or root fractures (6%). Most often one tooth was intruded (46.3%), followed by two teeth (32.4% ) and three or more teeth (21.3%). The majority of intruded teeth were displaced 2-8 mm. The age group of 6-12 years of age was most frequently involved and boys appeared to experience intrusion injuries more frequently than girls, and at an earlier age. Maxillary central and lateral incisors are the primary victims of intrusions and this seems to be identical to other trauma types and is possibly related to the known exposure to impacts of maxillary incisors. The reliability of clinical findings, such as lack of mobility (81.8%), metallic percussion tone (72.5%), and no pain to percussion (66%) was reasonably high, whereas a radiographic feature such as the obliteration of the periodontal ligament space appeared to be only a partly reliable diagnostic tool (52%).

A retrospective study of dento-alveolar injuries of children in Ankara, Turkey

Information concerning age and sex distribution, etiology, types, place and extent of trauma as well as seasonal variations, time difference between traumatic injury and seeking of dental care and number of traumatic injuries was recorded retrospectively from 150 patients. The study comprised 91 boys and 59 girls representing 246 dental injuries and 332 injured teeth (72 primary and 260 permanent teeth). The most common injuries were uncomplicated crown fracture (23.57%), subluxation (15.85%), avulsion (10.16%), lateral luxation (9.75%), complicated crown fracture and intrusion (8.4% and 8.94%, respectively). The occurrence of uncomplicated crown fractures was significantly higher (P<0.05) in the 10-12 years age group than other age groups. Lateral luxation and intrusion were significantly higher in the 1-6 and 7-9 years age groups (P<0.05, respectively).

Factors affecting the time of onset of resorption in avulsed and replanted incisor teeth in children

Resorption is the main reason for loss of replanted teeth. The outcome examined in this study is the timing of the onset of resorption. The effect of dichotomised dry and wet time intervals as well as the presence of additional crown damage and of contamination were determined. Of 84 replanted teeth, 67.5% developed resorptions. Twenty-eight had detectable additional crown damage with a more rapid onset being seen in these cases (P=0.009). The critical limit for dry time was 15 min (P=0.038) and significant differences persisted for greater limits also. Serial analysis of the association between the time of onset of root resorption and dichotomised wet time variables failed to yield any significant associations. There was visible contamination detected in 32 teeth and these exhibited a more rapid onset of resorption than the other cases (P=0.030). Teeth with inflammatory root resorption (12.8%) had a more rapid onset of resorption than those that developed replacement resorption (54.7%) (P<0.001). It is concluded that the risk of early resorption is increased in teeth that have additional damage or have contamination, or are kept in dry conditions for longer than 15 min.

The impact of treatment of dental trauma on the quality of life of adolescents ? a case-control study in southern Brazil

The aim of this study was to investigate the impact of treatment for Enamel-Dentin Fracture (EDF) on the daily activities of adolescents. This was a case-control study (1:4). The case group was composed of 40 adolescents from 11 to 17 years of age, presenting definitive restoration treatment for EDF for over 6 months. The control group was made up of 160 adolescents with no history of dental trauma and belonging to the circle of friends of the participants of the case group, matched by gender, age, and socioeconomic level. The outcome variable 'impact' was assessed through the Oral Impact on Daily Performances (OIDP). The independent variables were collected for being of interest to the study (dental trauma) or for acting as potential confounding factors (malocclusion, decay, and mother's education). Descriptive, univariate, simple and multiple logistic regression analyses were performed. Among the cases, the impact prevalence was 40.0%, whereas among the controls it was 16.9%. The more affected daily activities were showing the teeth (18.0%), eating (6.5%), speaking (2.0%), and cleaning the mouth (0.5%). The odds ratio of adolescents treated for EDF of presenting an impact on daily activities was 3.3 times (confidence interval 95%: 1.4-7.7) greater than among adolescents without dental trauma, controlling for mother's education, decay and the presence of malocclusion. Adolescents whose teeth have been esthetically treated for EDFs run a greater risk of presenting OIDP when compared to adolescents that have never suffered dental injuries.

Oral trauma in Brazilian patients aged 0-3 years

The aim of the present investigation was to gather data pertaining to dental trauma in 1654 patients aged 0-3 years, attended at the Baby Clinic of the School of Dentistry at Araçatuba-UNESP, Brazil. The prevalence of traumatic injuries was 16.3%. There was greater involvement of boys (62.6%), of children aged 1-2 years (39.9%) and of the maxillary central incisors (86%). Falls were more often the etiology for dental injuries (58.3%). There was a predominance of uncomplicated crown fractures (48.4%).

Traumatic dental injuries in children presenting for treatment at the Department of Pediatric Dentistry, Faculty of Dentistry, University of Jordan, 1997-2000

Data pertaining to traumatic dental injuries of children seeking care at the teaching clinics of the Department of Pediatric Dentistry, Faculty of Dentistry, University of Jordan over a period of 4 years were analyzed. The prevalence of traumatic dental injuries was 14.2% from 2751 subjects. The peak incidence of injury was 10-12-year age group. Boys were more affected (18.3%) than girls (10.1%). Most injuries occurred at home (63.2%), and falls were the leading cause of injuries (49.9%). Most injuries involved one tooth (69.3%) and maxillary central incisors were the most affected teeth (90.4%). The commonest injury was uncomplicated crown fracture (62.5%), then complicated crown fracture (28.7%). Only 17.1% of children sought treatment the same day or the day after the injury. At the initial examination, cases seen after a long post-traumatic period required more complicated treatment than those presented within a short time period. Preventive educational program should be instituted in Jordan, directed at parents and school teachers to inform them about the importance of traumatic dental injuries and the benefit of immediate attendance for dental treatment. Furthermore, improving the knowledge of dental practitioners through continuing education would also help in minimizing sequelae of traumatic dental injuries.

Vital pulp therapy with mineral trioxide aggregate

The present case report describes the treatment of complicated crown fractures using mineral trioxide aggregate (MTA). MTA was used as pulp-capping material after partial pulpotomy to preserve the vitality of the pulpal tissues in two cases. Follow-up examinations revealed that the treatment was successful in preserving pulpal vitality and continued development of the tooth.

Clinical outcomes for permanent incisor luxations in a pediatric population. I. Intrusions

A longitudinal outcome study was undertaken to identify variables that significantly influenced tooth survival as well as pulpal and periodontal outcomes for intruded permanent maxillary incisors of children and adolescents. All cases were treated between June 1988 and June 1998 in a teaching hospital clinic. Clinical and radiographic data were collected for 26 patients (19 males, 7 females) that represented 31 permanent maxillary incisors. Mean age at the time of injury was 9.3 years (range = 5.5-17.8 years). Mean time elapsed to follow up was 1380 days (range = 65-3394 days). Survival analysis was used to identify variables significantly related to the survival and pulp necrosis (PN) for these incisors. Proportional hazards regression yielded significant prognostic models for tooth survival and the diagnosis of PN (P < 0.05). Incisors intruded > 6 mm had significantly decreased survival compared with incisors intruded < 3 mm (5-year survival, 0.45 and 1.0, respectively, (P < 0.05)). Complex crown fractures were significantly related to the development of PN (P < 0.05). Logistic regression analysis showed that treatment method and severity of intrusion were related to the presence of replacement root resorption (P < 0.05). This study represents the largest sample of intruded permanent incisors examined in an outcome study of children and adolescents exclusively.

Definitive diagnosis of early enamel and dentin cracks based on microscopic evaluation

The diagnoses of cracked teeth and incomplete coronal fracture have historically been symptom based. The dental operating microscope at 16x magnification can fundamentally change a clinician's ability to diagnose such conditions. Clinicians have been observing cracks under extreme magnification for nearly a decade. Patterns have become clear that can lead to appropriate treatment prior to symptoms or to devastation to tooth structure. Conversely, many cracks are not structural and can lead to misdiagnosis and overtreatment. Methodic microscopic examination, an understanding of crack progression, and an appreciation of the types of cracks will guide a doctor to make appropriate decisions. Teeth can have structural cracks in various stages. To date, diagnosis and treatment are very often at end stage of crack development.

CLINICAL SIGNIFICANCE

This article gives new guidelines for recognition, visualization, classification, and treatment of cracked teeth based on the routine use of 16x magnification. The significance of enamel cracks as they relate to dentinal cracks is detailed.

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.

Prevalence of traumatic crown fractures to permanent incisors in a childhood population: Móstoles, Spain

- The aim of this study was to ascertain the prevalence of traumatic crown fractures in a childhood population and identify the risk factors associated with the same. A cross-sectional study was conducted, covering 470 schoolchildren and surveying socio-demographic variables, overweight, overbite, number of teeth, cause, setting, season, type of injury and restoration. We measured prevalence, performed univariate and multivariate analyses of risk factors for crown fracture, and calculated the Odds Ratio (OR) and its 95% confidence intervals (95% CI). Prevalence of traumatic crown fractures to permanent incisors was 17.4% (95% CI: 14-20.8). Falls were the most frequent cause of dental trauma (43.9%). Boys and children with overbite registered a 2.13- and 1.81-fold higher risk of crown fractures, respectively. Owing to high prevalence, crown fractures in schoolchildren aged 10 years constitute a public health problem. Being male and having overbite are risk factors for crown fracture. Healthcare promotion and education at health centres is called for to prevent such injuries.

Traumatized primary teeth in children assisted at the Federal University of Santa Catarina, Brazil

The goal of the present study was to identify the factors related to the occurrence of dental trauma in deciduous teeth. Over a period of 25 months, 85 children between 10 months and 6 years of age were assisted by the staff of the Pediatric Dentistry Clinic of the Federal University of Santa Catarina (UFSC) Florianópolis, Brazil. The children, all assisted by only one professional, a dentist working as a trainee in the Pediatric Dentistry Clinic, had 157 traumatized teeth treated. The occurrence of trauma was higher in male patients (51.8%) and in children between 1 and 3 years old. The average age was about =2.7 years. The 54.1% of the assisted children had more than one traumatized tooth and the repeat trauma occurred 16.7% of the time. Anterior teeth represented 98.7% of the cases and 76.4% of the trauma were on the maxillary central incisor teeth. Both sides of the mouth had approximately the same number of traumatic injuries. Luxations were more frequent (85.4%) than fractures (14.6%). Subluxations represented 38.8% of the luxated teeth. Falls were the main cause of trauma (78%). A percentage of 41.9 children were assisted by a dental professional during the first 24h after the incident. The study concluded that the deciduous dentition is mostly affected by luxations (subluxations) that occur specially on the maxillary central incisor teeth, in patients between 1 and 3 years of age. Falls are the most common etiological factor and more than one traumatized tooth is common. Some of the cases were repeat traumatic injuries.

An analysis of 58 traumatically intruded and surgically extruded permanent teeth

Fifty-eight traumatically intruded and mainly surgically extruded permanent teeth were followed up for 3 years and 4 months (mid-term results: 29 teeth) and 9 months (short-term results: 29 teeth) on average. Statistically, the mid-term results showed more cases of severe crown discoloration (54%) than the short-term results (9%), but no difference in pulpal and periodontal healing. Three teeth (5%) were lost. Factors which positively influenced pulpal healing were shallow intrusion depth, intact crown and immaturity of the root. Factors which positively influenced periodontal healing were shallow intrusion depth and minimal surgical manipulation. Alveolar bone healing was positively influenced only by shallow intrusion depth.