Therapeutic strategy for cracked teeth

The management of cracked teeth represents a difficulty because their diagnosis is complex and there is no consensus concerning their treatment. The present article explains this pathology within enamel and dentin and also focuses on the clinical consequences of crack development in dental tissue. As cracks have both biologic and mechanical implications, a complete review of the literature on the subject has enabled the development of a comprehensive diagnostic approach to identify cracked teeth and optimize their management. The elements of diagnosis are the bite test, transillumination, the pulp sensitivity test, the periodontal test, radiologic examinations, removal of existing restorations, and the use of quantitative light-induced fluorescence. Finally, the management of biologic and mechanical imperatives relating to the treatment of cracked teeth has allowed the proposal of a reliable and reproducible therapeutic strategy based on two pillars: the arrest of bacterial infiltration using immediate dentin sealing, and the limitation of crack propagation using relative cuspal coverage. In this article, the proposed clinical protocol is explained through the use of a decision map and is illustrated by a clinical case example.

Detection and Analysis of Enamel Cracks by Quantitative Light-induced Fluorescence Technology

INTRODUCTION

The ability to accurately detect tooth cracks and quantify their depth would allow the prediction of crack progression and treatment success. The aim of this in vitro study was to determine the capabilities of quantitative light-induced fluorescence (QLF) technology in the detection of enamel cracks.

METHODS

Ninety-six extracted human teeth were selected for examining naturally existing or suspected cracked teeth surfaces using a photocuring unit. QLF performed with a digital camera (QLF-D) images were used to assess the ability to detect enamel cracks based on the maximum fluorescence loss value (ΔFmax, %), which was then analyzed using the QLF-D software. A histologic evaluation was then performed in which the samples were sectioned and observed with the aid of a polarized light microscope. The relationship between ΔFmax and the histology findings was assessed based on the Spearman rank correlation. The sensitivity and specificity were calculated to evaluate the validity of using QLF-D to analyze enamel inner-half cracks and cracks extending to the dentin-enamel junction.

RESULTS

There was a strong correlation between the results of histologic evaluations of enamel cracks and the ΔFmax value, with a correlation coefficient of 0.84. The diagnostic accuracy of QLF-D had a sensitivity of 0.87 and a specificity of 0.98 for enamel inner-half cracks and a sensitivity of 0.90 and a specificity of 1.0 for cracks extending to the dentin-enamel junction.

CONCLUSIONS

These results indicate that QLF technology would be a useful clinical tool for diagnosing enamel cracks, especially given that this is a nondestructive method.

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.

The cracked tooth syndrome

The purpose of this article is to review the clinical features, diagnosis and management of the cracked tooth syndrome (CTS). The condition refers to an incomplete fracture of a vital posterior tooth that occasionally extends into the pulp. A lack of awareness of the condition coupled with its varied clinical features can make diagnosis of CTS difficult. Common symptoms include an uncomfortable sensation or pain from a tooth that occurs while chewing hard foods and which ceases when the pressure is withdrawn. The patient is often unable to identify the offending tooth or quadrant involved, and may report a history of numerous dental procedures with unsatisfactory results. Successful diagnosis and management requires an awareness of the existence of CTS and the appropriate diagnostic tests. Management options depend on the nature of the symptoms and extent of the lesion. These options include routine monitoring, occlusal adjustments, placement of a cast restoration and endodontic treatment. A decision flowchart indicating the treatment options available to the dental practitioner is presented.

Type and incidence of cracks in posterior teeth

STATEMENT OF PROBLEM

The use of magnified vision in the operatory has enhanced the early diagnosis of structural defects in the dentition and in existing restorations. There is little in the literature to guide the clinician on the significance of cracks and other interruptions in the integrity of teeth.

PURPOSE

This study characterized the type and incidence of cracks in posterior teeth and identified possible etiologic factors.

MATERIAL AND METHODS

An observational cross-sectional survey of 51 patients from a private practice examined during an 18-month period was used to identify 4 types of cracks in posterior teeth. The study identified both patient- and tooth-level variables present in each patient examined. The data were subjected to statistical analysis to determine whether correlations existed between the variables and cracks.

RESULTS

Cracks in teeth were shown to have chronicity and can be classified according to appearance. Variables such as the presence of a Class I or II restoration and the presence of excursive interferences were shown to significantly increase (P< .0001) the chances of a crack being present. Combinations of variables, such as interferences and a restoration, also increased the chance of a crack being present.

CONCLUSION

Within the limitations of this study, the presence of cracks in teeth was associated with the placement of a Class I or II restoration and with the presence of excursive interferences. Age played a role in the presence of stained or symptomatic cracks, which suggests that cracks have chronicity. Although many questions remain regarding prevention, it is evident that protecting teeth from excursive interferences and parafunction may thwart premature breakdown.

Incomplete tooth fracture – proposal for a new definition

Many terms have been used to describe incomplete tooth fractures. This paper reviews them, discusses the clinical features of incomplete tooth fractures and proposes a clinically representative definition.

Bacterial Contamination Of Cracks In Symptomatic Vital Teeth

As part of an ongoing study on the initiation of cracks in teeth, 20 teeth exhibiting symptoms consistent with the presence of dentinal cracks were examined. The presence of a cracked cusp was confirmed by the selective application of pressure either with a mirror handle or Fracfinder (Svenoka, Dental Instruments, Vasby, Sweden). Cracked cusps were fractured from the teeth after the removal of all existing restorations and were immediately placed into ten percent formalin. Subsequently, specimens were dehydrated, sputter-coated and examined under the scanning electron microscope (SEM). All the cracked cusps exhibited complete fracture of the dentine to the level of the dentino-enamel junction. No partial fractures were seen. Numerous bacteria of many morphological forms were present on the dentinal surfaces, of all fractured cusps, in all teeth. Cocci, bacilli and filamentous forms were consistently found. Many bacteria were in the process of division. While bacterial contamination of dentinal cracks has been described in histological studies, the nature and distribution of these bacterial and fungal forms has not been shown previously in any detail. Prior SEM studies investigating the nature and mechanisms of fracture have not revealed bacterial contamination of the fractured surface. This paper draws attention to the fact that all symptomatic cracks in teeth appear to 1. extend right through the dentine to the dentino-enamel junction, and 2. appear to be extensively contaminated by bacteria.

Preservation of the roots--management and prevention protocols for cracked tooth syndrome

It is essential that symptomatic fractures of teeth be suitably diagnosed to prevent propagation of the fracture and continuation of the symptoms. The importance of understanding the mechanism and progression of fractures within teeth is essential when considering the management of fractures within teeth. The relation of the fracture line to the pulp, periodontal ligament and root will influence the management protocols for the involved teeth. When does a Cracked Tooth Syndrome (CTS) become a cracked tooth i.e., unrestorable? Consideration is also required regarding when endodontic treatment should be commenced. Further, suitable-coronal restoration of teeth is required to prevent propagation of the fracture line and persistence of the symptoms. Patients diagnosed with CTS should be counselled in strategies to prevent CTS in other teeth.

[A newly developed method for taking pictures of tooth crown cracks for clinical records]

It is very important to examine fine cracks on the crown surface of traumatized tooth in the dental clinic because the presence of these cracks may cause discomfort or hypersensitivity of the tooth. By the emission of routinely used light, it is difficult to illuminate cracks, and the usual intraoral photography using strobe light emission is not useful to make records of cracks in most cases. In the present study, a method for taking pictures to record tooth crown cracks was newly developed using LED as a light source, and applied to patients with traumatized teeth in the dental clinic. The results were as follows: 1. Cracks on the tooth surface could be confirmed with the LEDs of all the colors used in this study. However, the blue LED enabled cracks in the incisal edge part to be more easily confirmed, and the white LED enabled cracks in the cervical part to be more easily confirmed. 2. Cracks of multiple modalities on the tooth surface was illuminated more often when the LED light was emitted at 45 degrees to the axis of the tooth than 90 degrees. 3. The light exposure field became wider by the use of the LED of diameter 5 mm than that of diameter 3 mm. However, the LED of diameter 3 mm was more favorable than that of diameter 5 mm for the observation of the cracks because the former could more easily change the direction of light emission.

Two new schemes for classifying propagating cracks in human tooth structure

Currently, the dental profession has no comprehensive classification method or scheme to identify the many types of propagating cracks in human tooth structure. This article presents two new and practical classification systems that encompass numerous types of cracks. The first is the more simplified--the Surface and Position Classification System. The second and more comprehensive system is the Directional Crack Propagation System.

Cracked tooth syndrome: diagnosis, treatment and correlation between symptoms and post-extraction findings

Although the cracked tooth syndrome has been known for over twenty years, it frequently remains undiagnosed because the condition is not sufficiently well recognized. Cracked tooth syndrome has been defined as an incomplete fracture of the dentine in a vital posterior tooth, and must be distinguished from a split tooth. A diagnosis can often be made by means of the history, and must be confirmed by reproducing the patient's symptoms. The ideal treatment consists of applying a stainless steel band to the tooth, with cessation of symptoms confirming the diagnosis, followed by a full coverage restoration. Case histories illustrating the syndrome are presented, and a further case is reported where a diagnosis of cracked tooth syndrome was made, and the tooth extracted, sectioned and stained to show the nature of the cracks and their relationship to the pulp.

The cracked tooth syndrome: additional findings

The results of this study add to the previous findings on the cracked tooth syndrome. Treatment to prevent further cracking is a must. Dentists should be aware of the syndrome and, after making the diagnosis, initiate necessary treatment.

The cracked-tooth syndrome and fractured posterior cusp

1. Even from such a small sample as that reported in this study, it is evident that the fractured cusp and cracked-tooth syndrome are common problems. The large number of fractured cusps compared to the cracked-tooth syndrome suggests that some of the cases of fractured cusp could have been diagnosed earlier. 2. It is most important that dentists be aware of the cracked-tooth syndrome in order to relieve the patient's discomfort, prevent the possible eventual loss of the pulp or tooth, and avoid unnecessary and possibly damaging treatment for misdiagnosed facial pain. 3. Conservation of tooth structure in restorative procedures is most necessary in order to prevent the cracked-tooth syndrome or fractured posterior cusp.

The undiagnosed split-root syndrome

The split-root syndrome is an often misdiagnosed painful condition. The major causes of the splits have been discussed. In addition, classical symptoms associated with this syndrome have been illustrated by two case reports to facilitate the syndrome's recognition.