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PubMedDate not supplied

Treatment of severe pre-eruptive intracoronal resorption of a permanent second molar.

Pre-eruptive intracoronal resorption is a lesion often located within the dentin, adjacent to the dentin-enamel junction, in the occlusal aspect of the crown. As the lesions resemble caries, they are often referred as "pre-eruptive caries." The purpose of this case report was to describe the diagnosis and treatment of a permanent molar with pre-eruptive intracoronal resorption and to elaborate on possible associated clinical problems. After surgical exposure of the unerupted tooth, the tooth structure in the resorbed area was removed and the tooth was restored with glass-ionomer material. Three months after the treatment, partial pulpotomy had been performed and the restoration was replaced by amalgam. Elaboration on possible associated clinical problems is provided.

Child↗
PubMed2001

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%).

Accidental Falls↗
PubMedDate not supplied

Reattachment of fractured teeth: a review of literature regarding techniques and materials.

Anterior crown fractures are a common form of injury that mainly affects children and adolescents. The position of maxillary incisors and their eruptive pattern carries a significant risk for trauma. In the pre-adhesive era, fractured teeth needed to be restored either with pin-retained inlays or cast restorations that sacrificed healthy tooth structure and were a challenge for clinicians to match with adjacent teeth. The development of adhesive dentistry has allowed dentists to use the patient's own fragment to restore the fractured tooth. Since then, several successful case reports that use a variety of techniques and materials to reattach fractured teeth have been published. This article presents a comprehensive literature review on techniques and materials used to restore uncomplicated dental trauma.

Adolescent↗
PubMed2005

The crowning achievement: getting to the root of the problem.

An ideal goal of oral-craniofacial dental reconstructive therapy is to establish treatment modalities that predictably restore functional tissues. One major area of focus has been in the area of dental materials with marked improvements in the design of materials used to restore teeth/periodontium/bone lost as a consequence of disease or disorders. With advances in understanding the cell and molecular controls for development and regeneration of tooth structures, it is now possible to consider therapies that promote regeneration of lost tissues, along with replacement of these tissues. This review presents a background on our current knowledge as to the composition of the tooth/periodontium followed by a discussion on successes to date, both in vitro and in vivo, toward regenerating a whole tooth and next steps required to regenerate a functional tooth.

Humans↗
PubMed2005

A clinical study comparing marginal and occlusal accuracy of crowns fabricated from double-arch and complete-arch impressions.

BACKGROUND: The double-arch impression technique is widely used in the provision of laboratory fabricated restorations. However, there is little clinical evidence to support or refute its use. The aim of this prospective clinical study was to evaluate the occlusion and marginal fit of posterior full crowns made from double-arch impressions, and to compare these to control crowns fabricated from conventional complete-arch impressions. METHODS: Ten patients requiring single posterior ceramo-metal full crowns had both double-arch and complete-arch impressions taken of the prepared tooth. Two crowns were fabricated for each tooth, using the casts made from both impression methods. Both crowns were tried in and the occlusion and margins evaluated. The results were composed using nonparametric statistical analysis with the probability level for significance at alpha=0.05. RESULTS: The crowns fabricated from the double-arch impression were found to be more accurate in closure to the intercuspal position and had fewer interferences in lateral excursions. There were no significant differences between the two crown groups regarding protrusive interferences and margin quality. CONCLUSIONS: Crowns fabricated from the double-arch impressions were equivalent in marginal accuracy and superior occlusally to crowns fabricated from the complete-arch impressions.

Crowns↗
PubMed2001

The fracture behaviour of human and pig molar cusps.

Masticatory efficiency depends upon the ability of the molar cusps to apply concentrated bite forces to food particles and simultaneously to withstand the dental stresses that may cause enamel fracture. This study investigated how low-crowned molar cusps in omnivorous mammals, specifically humans, Homo sapiens, and pigs, Sus scrofa, resist fracture under compressive load. A uniaxial compressive load was applied to individual molar cusps with a materials testing machine. The progressive loading and deformation of the cusps were recorded for interrupted and continuous tests. In interrupted tests, the appearance of progressive cusp fracture was recorded. Stiffness and fracture stresses were calculated from continuous test results. Pig cusps responded to both interrupted and continuous loads with greater deformation; progressive crumbling of the cusp tip resulted in new occlusal contacts on enamel lophs. Conversely, human cusps showed minimal breakage before failure. Continuous compressive tests demonstrated the greater stiffness of human cusps, as well as the capacity to sustain higher cusp tip stresses. The greater stiffness and high fracture resistance of human cusps may be attributed to the thickness of enamel. Test results reflected fundamentally different means of crown stress management that correspond with phylogenetic differences in masticatory function.

Animals↗
PubMed2002

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.

Composite Resins↗
PubMed2004

Prevalence of crown fractures in 8-10 years old schoolchildren in Canoas, Brazil.

The objective of this work was to evaluate the prevalence of children with crown fractures in permanent anterior teeth in 206 schoolchildren (104 girls and 102 boys) between the ages of 8 and 10 years, enrolled in three public schools in the city of Canoas, Brazil. The prevalence found was 17% with no significant difference between boys and girls, as well as between the ages. The most affected tooth was the maxillary central incisor, and a majority of the children showed only one affected tooth (88.6%). The types of fracture most commonly found were oblique and horizontal, and the portions of dental structures most affected were 'enamel only' and 'enamel and dentin'. Only seven children (20%) sought out dental treatment.

Age Factors↗
PubMedDate not supplied

Effects of elevated temperatures on various restorative materials: an in vitro study.

In cases of mass disasters associated with fire, identification of the burnt victims can be a real challenge to the forensic team. Teeth and their restorations play a significant role to aid in the identification process, as various restorative materials have varying resistance to high temperatures. A study was undertaken to evaluate the changes taking place on teeth restored with amalgam, composites, glass ionomers, heat cure acrylic, and ceramics. The specimens were placed in a furnace and heated to predetermined temperatures of 200, 400, 600, 800, and 1000 degrees C and the changes were examined using a digital camera and stereomicroscope. Our observations show that while some restorations were able to withstand elevated temperatures, others were reduced to an unrecognizable mass at relatively low temperatures.

Acrylic Resins↗
PubMed2005

The prosthodontic concept of crown-to-root ratio: a review of the literature.

Crown-to-root ratio is intended to serve as an aid in predicting the prognosis of teeth. However, controversy persists as to its impact on diagnosis and treatment planning. This article critically reviews the available literature on the crown-to-root ratio assessment and criteria for evaluation of abutment use of periodontally compromised teeth. A Medline search was completed for the time period from 1966 to 2003, along with a manual search, to locate relevant peer-reviewed articles and textbooks published in English. Key words used were "crown-to-root ratio," "periodontal compromised dentition," "mobility," and "biomechanics." There was a dearth of evidence-based research on the topic. Although the use of the crown-to-root ratio in addition to other clinical indices may offer the best clinical predictors, no definitive recommendations could be ascertained.

Alveolar Bone Loss↗
PubMed2003

Biologic restoration of primary anterior teeth: a case report.

Restoration of primary maxillary incisors, severely destroyed by trauma or caries is a commonly faced problem in a Pediatric dental clinic. Most cases are observed in children with early childhood caries. In the past, the only option would have been to extract the affected teeth and replace them with prosthetic substitutes. However, the availability of natural crowns and roots would allow the use of biologic restorations to preserve the integrity of patient's natural dentition as presented in this case report.

Child, Preschool↗
PubMed1999

Surgical extrusion of crown-root-fractured teeth: a clinical review.

AIM: In this clinical study combined surgical and endodontic treatment was performed in 20 cases of crown-root fracture and the outcomes reviewed. METHODOLOGY: Surgical treatment involved a conventional extraction and stabilization technique. Root canal treatment using calcium hydroxide was performed. Before root canal obturation, a calcium hydroxide dressing was maintained for 3 months. RESULTS: Follow-up examinations, which varied between 6 and 36 (mean 14.5) months, showed that there were no radiographic and clinical signs of progressive root resorption, marginal bone loss or periapical disease in all except one case. CONCLUSIONS: The favourable results of this study demonstrate that surgical extrusion in teeth with crown-root fractures may be an alternative treatment to orthodontic extrusion.

Adolescent↗
PubMed1998

[The late treatment results in fractures of the masticatory teeth].

Late results of treatment of the crown and root fractures of masticatory teeth are assessed in 23 patients. The method of treatment consisted in provisional fixation of a fragment with wire for further permanent fixation by special filling and a metal crown. The method is simple, its results are good, and it is recommended for practical dentistry.

Adolescent↗
PubMed2000

Crown fractures: effectiveness of current enamel-dentin adhesives in reattachment of fractured fragments.

OBJECTIVE: The introduction of the current enamel-dentin adhesives has simplified the reattachment of fractured dentinal fragments. The objective of this study was to determine the strength needed to detach coronal fragments reattached with the most recent adhesives. METHOD AND MATERIALS: A complete coronal fracture was caused on the incisal one third of 40 noncarious maxillary and mandibular lateral and central incisors. Each fractured coronal fragment was reattached to its tooth with the enamel-dentin adhesive Scotchbond MP, All-Bond 2, Dentastic, or One-Step (10 specimens each). RESULTS: There was no statistically significant difference between 2 similar fourth-generation adhesives that use orthophosphoric acid as etchant (Dentastic and All-Bond 2) and a fourth-generation adhesive that uses maleic acid as etchant (Scotchbond MP). The values obtained with the fifth-generation adhesive (One-Step) were significantly inferior to those obtained with the other 3 enamel-dentin adhesives. CONCLUSION: In the reattachment of fractured tooth fragments, fourth-generation adhesives can guarantee a bonding force stronger than fifth-generation adhesives.

Dental Bonding↗
PubMed2004

Further study of restored and un-restored teeth subjected to high temperatures.

Forensic dentistry has been shown to be of fundamental importance in medico-legal investigations aimed at identifying human remains involving high temperature incidents because dental remains and prosthetic devices are resistant to quite high thermal change. In this project we studied teeth containing class I and V amalgam and composite fillings and compared them to un-restored teeth when exposed to high temperatures. Twenty five un-restored teeth, 25 teeth with class I amalgam restorations, 25 teeth with class V amalgam restorations and 25 teeth with class I composite fillings were placed in a furnace and heated at a rate of 30 degrees C/min. The effects at the predetermined temperatures 200, 400, 600, 800, 1000 and 1100 degrees C were examined macroscopically and then observed microscopically by means of a stereomicroscope. Our observations showed that the class I amalgam restorations at the different temperature levels remained in place, maintaining their shape despite disintegration of the crowns, whilst the class I composite restorations remained in place but in an altered shape. Comparing restored with un-restored teeth we observed different responses in crown disintegration at the different temperature levels.

Acrylic Resins↗
PubMed1996

Prader-Willi syndrome--a case report of the multidisciplinary management of the orofacial problems.

A 24-year-old man with Prader-Willi syndrome presented with a class III malocclusion, featuring maxillary hypoplasia and severe enamel deficiency. Treatment involved orthodontic alignment, surgical advancement of the maxilla and restorative treatment to augment vertical facial height, improve the final occlusion and increase short clinical dental crown heights. The principal features of the syndrome and the management of this case are discussed.

Adult↗
PubMed2006

Complicated crown fracture: a case report.

This case report describes the treatment of a severe crown fracture of an immature mandibular permanent incisor in a 12 year-old boy referred to the Dental Traumatology Center of UNIGRANRIO University. After conventional endodontic procedures and dressing with calcium hydroxide, an apical plug was made with mineral trioxide aggregate in order to avoid an overflow of gutta-percha and endodontic sealer into the periapical tissues. Two years later, the tooth was clinically asymptomatic and radiographs showed total repair of the apical lesion.

Child↗
PubMed2000

Comparison of the number and diameter of dentinal tubules in human and bovine dentine by scanning electron microscopic investigation.

Detailed information on dentine structure is essential for interpreting data from investigations on dentine-adhesive materials. The purpose here was to compare the number and diameter of dentinal tubules at similarly prepared surfaces of bovine permanent central incisors and human deciduous and third molars. In bovine teeth, crowns and roots were used; in human samples only the crowns were investigated. Tubule density in the middle layer was higher in bovine root (BR) dentine (number of tubules per mm(2)+/-SD: 23, 760+/-2453) than in human deciduous (HD) (18,243+/-3845), human permanent (HP) (18,781+/-5855), and bovine coronal (BC) (17, 310+/-2140) dentine. The corresponding values for the deep layer were 23,738+/-4457 (BR), 24,162+/-5338 (HD), 21,343+/-7290 (HP), and 20,980+/-4198 (BC). No significant differences were found for the number of dentinal tubules in bovine coronal dentine compared to the dentine of human deciduous and permanent molars. The mean diameter of bovine dentinal tubules was slightly, but not significantly, higher than in human dentine (middle layer/deep layer+/-SD): BC, 2. 85 microm+/-0.18/3.50 microm+/-0.33; BR, 3.10 microm+/-0.33/3.23 microm+/-0.30; HD, 2.55 microm+/-0.16/2.82 microm+/-0.28; HP, 2.65 microm+/-0.19/2.90 microm+/-0.22. These findings demonstrate that corresponding coronal dentine layers of human deciduous and permanent molars, and of bovine central incisors, are not significantly different in their number of tubules per mm(2) and their tubule diameter, whereas tubule density in bovine root dentine is significantly higher. These results suggest that provided standardized preparations are used, bovine incisor crown dentine is a suitable substitute for human molar dentine in adhesion studies.

Adolescent↗