Incidence rates for complete cusp fracture

OBJECTIVES: Although complete cusp fracture is acknowledged to occur frequently, incidence rates have been reported rarely. This study determined incidence rates for complete coronal cusp fracture per person and per tooth type. METHODS: All fractures presenting among enrollees in a dental health maintenance organization using two geographically isolated clinics were noted for 105 days. For a sample of these enrollees, likelihood of attending the clinic in the event of a fracture was assessed through a telephone survey, and the at-risk status of all teeth was determined through a record survey. Incidence rates were calculated for persons, and for individual tooth types for all complete fractures and for non-carious complete fractures. In addition, for posterior teeth the distribution of fractured cusps, and the severity of fractures were examined. RESULTS: Per-person incidence rates for complete coronal fractures for all teeth were 89.0 and 72.7 per 1000 person years, respectively, for all fractures and for non-carious fractures. The rates for all anterior and all posterior teeth were 10.2 and 69.9, respectively, for all non-carious fractures. In mandibular posterior teeth, lingual cusps fractured twice as frequently as facial cusps, while the opposite was true for maxillary premolars. Among maxillary molars, the mesiofacial and distolingual cusps fractured most frequently. The large majority of fractures exposed dentin (95%), while pulpal exposure occurred infrequently (3%). A minority of fractures extended below the gingival crest (24%) or the DEJ (25%). CONCLUSIONS: This is the first report of fracture incidence rates for enumerated persons and teeth at risk and as such helps define the magnitude of the problem for dentists and their patients.     

Fractures of posterior teeth in adults

Examined in this study were 191 patients with 206 complete or incomplete fractures of posterior teeth. The patients ranged in age from 14 to 76 years, with 66.5% younger than 40 years. The number of fractures occurring in each arch was almost equal. The mandibular first molar was the most frequently fractured posterior tooth. The lingual cusps of mandibular molars fractured more often than did the buccal cusps of mandibular molars by a ratio of 2 to 1. In maxillary molars, buccal and lingual cusps fractured with almost equal frequency, but, in maxillary premolars, the lingual cusps fractured slightly more often than buccal cusps. Data gathered on the widths of the isthmuses of restorations in 109 teeth showed that fewer fractures occurred in teeth with more conservative restorations, with widths of isthmuses a quarter of the inter-cusp distance, and intact marginal ridges.     

Consequences of posterior cusp fracture

Although posterior cusp fracture occurs frequently, its consequences are not well-delineated. This study recorded short-term outcomes (distribution of fractured teeth and cusps, fracture severity, and treatment received up to two years postfracture) for 517 fractured teeth from 498 subjects at a large group practice. Maxillary and mandibular tooth fractures occurred with similar frequency. In the maxillary arch, first and second molars and premolars fractured with roughly the same frequency; premolar fractures were more severe. In the mandible, first molars accounted for approximately 50% of all fractures and were most likely to be severe fractures. Nonholding cusps were more likely to fracture in both arches. Proportions of fractured teeth receiving "catastrophic" treatment were low (3% extraction; 4% endodontic treatment) and the large majority of fractured teeth were treated in a single visit using direct restorative materials. A knowledge of the relatively small proportions of fractured teeth that suffer serious consequences and the tooth-specific distributions of cusp fracture should help dentists and patients to make informed decisions regarding preventive restorative intervention prior to fracture.     

Multidisciplinary approach to traumatized teeth: a case report

Abstract – Treatment of crown fractures often requires a multidisciplinary approach. In the anterior teeth, reestablishment of proper esthetics and function is quite important for the patient. However, crown‐root fractures with fracture line below the gingival attachment or alveolar bone crest presents restorative difficulties. This case report presents a cervical tooth fracture that had been treated with minimal invasive approach with different disciplines. The tooth had endodontic treatment and a glass‐fiber post, and a composite core was accomplished. Then, the tooth was extruded to the desired level with orthodontic forced eruption before definitive restoration.     

A survey of cusp fractures in a population of general dental practices

PURPOSE: This study was conducted to expand the knowledge on the incidence of complete cusp fractures of posterior teeth in Dutch general practices. MATERIALS AND METHODS: During a 3-month period, data were obtained from 28 general practitioners, representing 46,394 patients. For each new case of complete cusp fracture, clinicians recorded information using a standard form with questions relating to location of the fracture, cause of fracture, and restorative status of the tooth prior to the cusp fracture. RESULTS: There were 238 cases of complete cusp fracture recorded. The results of this study indicate an incidence rate of cusp fractures of 20.5 per 1,000 person-years at risk. Molars were more frequently registered with cusp fractures than premolars (79% vs 21%). Maxillary molars presented more fractures of buccal cusps (66% vs 34%), while mandibular molars presented more fractures of lingual cusps (75% vs 25%). Almost 77% of the cases had been restored on three or more surfaces. Statistical analysis revealed a positive correlation between history of endodontic treatment and subgingival fracture location. Mastication was most frequently reported as the cause for fracture (54%), although one can argue whether the occlusal force was the cause or the immediate reason. CONCLUSION: This study revealed that complete cusp fracture is a common phenomenon in dental practice and has shown differences in cusp fracture with respect to tooth type and restorative status of the tooth. Teeth with a history of endodontic treatment are susceptible to unfavorable subgingival fracture locations.     

Outcomes for root-fractured permanent incisors: a retrospective study

PURPOSE: The objective of this study was to assess the outcomes for treated root-fractured permanent incisors with respect to pulp vitality, root tissue union, and tooth survival and to examine the effects of clinical and radiographic parameters and rigid splinting on the outcome. METHODS: Eighty-four teeth were identified and data extracted from case notes prior to transfer to an SPSS data base for analysis. The odds ratios for each factor were calculated and the significance of differences was determined. Tooth loss and relevant risk variables were examined using Cox's regression model and Kaplan-Meyer survival curves. RESULTS: Fourteen (17%) had fractures in the apical third, 47 (56%) in the middle third, and 23 (27%) in the coronal (gingival) third. Twenty-four (29%) also had crown fractures involving enamel and dentine. Crown fractures were identified as significant risk factors for pulp vitality. Loss of pulp vitality, horizontal displacement, and extrusive displacement of the coronal fragment were significant risk factors for hard root tissue union. Survival was poorest with gingival third fractures with 14 (61%) of these teeth being lost. Splinting rigidly had no significant effect on pulp vitality and type of root tissue healing. CONCLUSIONS: Loss of pulp vitality was significantly associated with enamel-dentine crown fracture. Hard root tissue union was significantly affected by pulp necrosis and luxation of the coronal fragment. Survival was poorest for root fractures within the gingival third of the root. Splinting with rigid fixation had no significant effect on pulp vitality and type of root tissue union.     

Anatomy of cusps of posterior teeth and their fracture potential

Fracture of cusps on posterior teeth, especially those carious or restored, is a major cause of tooth loss, Nonfunctional cusps fracture more often than the functional; mandibular cusps fracture more often than maxillary cusps. This study examined functional and nonfunctional cusps of the maxillary and mandibular posterior teeth in four different parameters; (1) buccolingual width, (2) angle of cuspal inclination, (3) thickness of enamel, and (4) angle of inclination of the dentinoenamel junction. Measurements of functional cusps, except those in maxillary premolars established differences that may explain the frequency of frequency of fracture. These parameters of functional and nonfunctional cusps suggest that the cuspal anatomy has a relationship to the fracture potential of cusps.     

Root Fractures in permanent teeth: a clinical review

A retrospective study of 22 root fractures in 21 patients was performed. Ten patients were less than 11 years of age, and boys were involved more often than girls. Ten patients had more than one injured tooth, but there was no case of alveolar fracture. Twenty-one of the teeth were upper central incisors. Only 11 teeth were seen within the first week, so that not all teeth were splinted and not all displaced teeth were repositioned. Long-term clinical and radiographic review showed that loss of vitality of the coronal pulp could not be reliably detected for at least 1 year. No tooth became abscessed or developed a sinus tract, and resorption of bone at the fracture line was observed in only one out of five non-vital teeth. Lack of displacement and placing of a splint increased the chances of the pulp remaining vital and healing of the fracture occurring with hard tissue. Sclerosis of the coronal pulp occurred mainly when healing was by connective tissue. The apical pulp always remained vital, and there was sclerosis of the apical pulp in almost every case.     

牙齿折断性损伤分类和治疗原则

牙齿折断性损伤分为：冠折、根折和冠根折。冠折时建议采用断冠粘接,较年轻恒牙建议应用盖髓术或部分牙髓切断术以保持牙髓活性;根折时,建议尽早复位;冠根折时建议采取急诊处置,临时粘接断冠。在根中1/3根折、根颈1/3根折和冠根折时,序列治疗有助于保存断冠。     

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??Teeth fractures include crown fracture?? root fracture and crown-root fracture. If the tooth fragment is available?? it can be bonded to the tooth. In young patients with immature?? still developing teeth?? it is advantageous to preserve pulp vitality by pulp capping or partial pulpotomy. Also?? this treatment is the choice in young patients with completely formed teeth. If displaced?? reposition the coronal segment of the tooth as soon as possible. As an emergency treatment a temporary stabilization of the loose segment to adjacent teeth can be performed. Sequential therapy for traumatized teeth with mid-root fracture or cervical third fracture or crown-root fracture could preserve the coronal fragment.     

Spontaneously healed horizontal root fracture in maxillary first premolar: report of a case

Abstract –  Root fractures of the posterior teeth are rare and occur as a result of severe trauma. This study describes the horizontal root fracture of a maxillary first premolar. The fractured roots were discovered during a routine radiographic examination. The tooth was asymptomatic and responded positively to electric pulp testing. The patient reported accidental trauma, which occurred 14 years before. Our case is an example of spontaneously healed fractured roots. The interesting findings were that the healing was observed even in the presence of two roots, including preservation of the vitality of the pulp.     

牙隐裂的临床研究

流行病学调查资料曼示,随着口腔卫生状况的改善,龋病和牙周病的患病率逐渐下降,牙折成为工业化国家人们牙齿丧失的重要原因之一.牙齿的折裂根据程度和所涉及组织的不同分为釉质的龟裂、牙尖折裂、牙隐裂、牙齿劈裂和牙根纵裂5种.根据牙髓状况和折裂程度又分为活髓牙和死髓牙的完全和不完全折裂.其中活髓牙的不完全折裂被称为牙隐裂,有临床症状的牙隐裂则称为隐裂牙综合征.本文对牙隐裂的临床研究作一综述,为牙隐裂的诊断和治疗提供思路.     

In vivo fractures of endodontically treated posterior teeth restored with amalgam

The cumulative survival rate (retention of both cusps) and the fracture pattern of 1639 endodontically treated posterior teeth were assessed in a retrospective study. All teeth had an MO/DO or an MOD cavity restored with amalgam without cuspal overlays. The 20-year survival rate of teeth with an MO/DO cavity was markedly higher than that of teeth with an MOD cavity. The lowest survival rate was found for the upper premolars with an MOD cavity: 28% of these teeth fractured within 3 years after endodontic therapy, 57% were lost after 10 years, and 73% after 20 years. Generally, the cusp most prone to fracture was the lingual one, and lingual fractures caused significantly more damage to the periodontal tissues than did facial or total crown fractures. The severity of periodontal damage increased with posterior location of the tooth. By far the most serious failures, irrespective of the cavity type, were found for the upper second molar, as 10 of 29 fractures led to extraction. It is concluded that amalgam, especially in MOD cavities, is an unacceptable material for restoration of endodontically treated posterior teeth if used without cuspal overlays.     

In vivo fractures of endodontically treated posterior teeth restored with amalgam

Abstract The cumulative survival rate (retention of both cusps) and the fracture pattern of 1639 endodontically treated posterior teeth were assessed in a retrospective study. All teeth had an MO/DO or an MOD cavity restored with amalgam without cuspal overlays. The 20-year survival rate of teeth with an MO/ DO cavity was markedly higher than that of teeth with an MOD cavity. The lowest survival rate was found for the upper premolars with an MOD cavity: 28% of these teeth fractured within 3 years after endodontic therapy, 57% were lost after 10 years, and 73% after 20 years. Generally, the cusp most prone to fracture was the lingual one, and lingual fractures caused significantly more damage to the periodontal tissues than did facial or total crown fractures. The severity of periodontal damage increased with posterior location of the tooth. By far the most serious failures, irrespective of the cavity type, were found for the upper second molar, as 10 of 29 fractures led to extraction. It is concluded that amalgam, especially in MOD cavities, is an unacceptable material for restoration of endodontically treated posterior teeth if used without cuspal overlays.     

Unusual fracture of a mandibular second premolar: a case report.

Root fractures of posterior teeth, which are defined as fractures involving cementum, dentin, and pulp, are relatively uncommon among dental traumas. This study describes an unusual horizontal fracture of a mandibular second premolar. The tooth was asymptomatic and the fracture unnoticed until the crown broke off completely. The patient had no recollection of a causative event nor was there any evidence of previous physical trauma. The tooth was extracted, embedded in resin, sliced, and examined with different light microscopes. It was concluded that the tooth had been damaged previously but not to the extent that the pulp was seriously damaged. Resorption over a period of time eventually caused the final fracture.     

后牙折裂发病及危险因素的临床研究

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后牙折裂发病情况的临床观察和分析

目的 探讨牙折裂的原因,提出预防和治疗的方法。方法 对89例患者89颗折裂牙的发病年龄、性别、牙位及病史进行分类比较。结果 89例患者中,男46例,女43例,男女之比为1.07∶1。31～60岁71例,占79.78%,其中41～50岁比例最高,达40.70%。第一磨牙折裂牙最多见。牙折前无治疗史的57个,有治疗史的32个,包括牙髓干尸治疗25个,根管治疗7个。结论 牙折裂多见于磨牙区,且第一磨牙发病率最高,这与牙本身组织结构的缺陷、咬合创伤有关,也与牙本质中有机质、无机质相对含量随年龄变化有关。有效的牙体牙髓治疗与修复,包括充填体的选择,根管治疗后作全冠修复,以及严格的备洞原则及治疗后调牙合,具有早期治疗和预防牙折裂作用。?     

Prognosis of root-fractured permanent incisors

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

Factors affecting treatment outcomes following complicated crown fractures managed in primary and secondary care

Abstract – The aims of this retrospective observational study were to determine the factors which affect treatment provision and the Median Survival Time (MST) for maintenance of tooth vitality following complicated crown fracture. The survey was carried out for patients treated at Newcastle Dental Hospital (NDH) according to departmental guidelines over a 2‐year period following the introduction of a new protocol for management of these types of injuries. Seventy‐three cases of complicated crown fracture were identified in 69 children with a mean age of 10.3 years (SD = 2.5 years). Seventy‐one percent of the fractures occurred in males (M:F ratio was 2.5:1). Fifty‐one percent of the complicated crown fractures were in immature teeth. Of the 73 traumatised teeth, 45% presented initially in general dental practice (GDP), 37% at the dental hospital and 8% at local accident and emergency departments with the remaining 10% seen at other or unrecorded locations. Of the 41 fractures, which presented initially at a location other than the dental hospital, 38% were referred to the dental hospital without the provision of an emergency pulp bandage. The overall definitive treatments provided for the 37 open apex teeth included pulp cap (19%), partial pulpotomy (32%), cervical pulpotomy (8%) and pulpectomy (35%), while for the 36 closed apex teeth it was pulp cap (28%), pulpotomy (11%), and pulpectomy (61%). Of the 30 teeth, which underwent vital pulp therapy (18 open and 12 closed apex), the MST for the 15 teeth treated with pulp caps was 1460 days (95% CI: 1067, 1853) while for the 15 teeth treated with pulpotomies it was 1375 days (95% CI: 964, 1786). There was no statistically significant difference in the MST between teeth treated with pulp caps and pulpotomies. In conclusion, the proportion of patients referred to secondary care with complicated crown fractures without provision of a pulp bandage is of some concern. More conservative treatment of closed apex teeth sustaining complicated crown fractures, utilizing vital pulp therapy techniques would appear to be appropriate.     

Survival of intentionally retained permanent incisor roots following crown root fractures in children

Retaining tooth roots, following crown loss, confers a number of benefits including the preservation of alveolar bone. Intentional root retention in adults has been widely investigated but little is known about this treatment approach in children. Therefore, the aim of the present study was to investigate the clinical outcomes associated with permanent anterior root retention in a young population. The study group comprised 53 children who had received treatment in the paediatric dentistry clinic, Charles Clifford Dental Hospital, Sheffield, UK, over the past 10 years, following a complicated crown root fracture of a permanent maxillary incisor at or below the gingival margin. Data relating to patient age at crown root fracture, gender, previous trauma history, tooth vitality, treatments performed and clinical outcomes were obtained retrospectively using patient records. The mean age of the subjects at initial crown root fracture was 12.1 years (range 8.3–15.8 years) and there were more than twice as many males (n = 37, 70%) as females (n = 16, 30%). In just over half of the cases seen (n = 29, 54%), the tooth involved was already nonvital at the time of crown root fracture. For the majority of these nonvital teeth (n = 27, 93%), primary treatment had comprised placement/replacement of a calcium hydroxide root dressing. The remaining two teeth did not require root treatment as a satisfactory gutta percha root filling was already present. A variety of treatments was undertaken for the 24 vital roots: in 15 (63%) cases the pulp was extirpated and calcium hydroxide placed; three (12%) cases were subject to a pulpotomy; five (21%) cases were left untreated with the hope that vitality would be maintained following gingival healing and in one case the radicular pulp was extirpated and immediately obturated with gutta percha. The mean time that the roots were kept under review was 2.6 years (± 1.57, range 0.6–6.8). During this period, only five roots (9%) had to be removed due to persistent periapical infection. There were no complications associated with the five cases where vital root submergence had been permitted but all three cases which had initially undergone a pulpotomy subsequently presented with pulpal necrosis necessitating pulpal extirpation and calcium hydroxide therapy. These findings indicate that efforts to retain permanent anterior roots in a young population are justified in view of the high clinical success rate of over 90% over a 2‐year period.