Cracked tooth: Diagnosis and Adhesive Treatment
Cracks in teeth may occur in both the horizontal and vertical directions, involving the crown and/or root. The etiology is generally a result of occlusal forces and iatrogenic procedures.
Crown and crown-root fractures are usually incomplete fractures commencing in the crown of the posterior teeth and extending towards the cemento-enamel junction, or apically into the root. At first, this may become apparent in the form of a fine, superficial fracture line, and in later stages it may develop into a continuous crack, eventually causing the tooth to split.
Vertical root fractures are longitudinally orientated fractures of the root that extend from the root canal to the periodontium. Vertical root fractures most commonly occur in root canal treated teeth and among patients over 40 years old.
During a routine clinical check up, the dentist should pay attention to crack lines, especially in the posterior region. A cracked tooth is often detected too late, when a patient visits with symptoms of pain.
Classification of fractures.
The term longitudinal fracture typically describes fractures that extend vertically over time. These linear fractures tend to grow and change, as opposed to those resulting from impact trauma.
In dental literature there is a lot of misunderstanding about the terminology of fractures. The American Society of Endodontics divided longitudinal tooth fractures into five groups.
The first four groups originate in the crown of the tooth, and the last in the root. There are distinct delineations, as fractured cusps and vertical root fractures imply a complete or incomplete break of the tooth; craze lines and cracked teeth are only incomplete breaks in teeth; and split teeth are only complete breaks in teeth.
Group I: Craze lines
Group II: Fractured Cusp
Group III: Cracked Tooth
Group IV: Split Tooth
Group V: Vertical Root Fracture:
Case ReportMaxillary right upper second molar with a clear crack line. The cold vitality test with carbon dioxide snow (CO2 – Odontotest, Fricar A.G., Zurich, Switzerland) showed sensitive reaction of the pulp typical for the vital pulp, and the tooth was not sensitive during percussion test. The radiograph did not show an inflammatory lesion (Fig 2). A 43-year-old male patient presented in the dental office with typical symptoms of a cracked maxillary right upper second molar. The following clinical symptoms were recorded during patient anamnesis: – increased pain when consuming cold food or drink - sharp pain when biting, as the applied occlusal force increased - pain on release of pressure when eating fibrous foods - pain increased during the act of tooth grindin. The clinical examination with magnification (Zeiss loops 4.0) showed a clear crack line extending through the distal marginal ridge (Fig 1).
Fig 1.?Maxillary right upper second molar with a clear crack line. ??The cold vitality test with carbon dioxide snow (CO2 – Odontotest, Fricar A.G., Zurich, Switzerland) showed sensitive reaction of the pulp typical for the vital pulp, and the tooth was not sensitive during percussion test. The radiograph did not show an inflammatory lesion (Fig 2).
Fig 2. ?The radiagraph of the tooth 17 ?The purpose of the treatment was to immediately stop the crack extension obtaining adhesive composite indirect restoration with total cusp coverage. ??At the same appointment, the tooth was prepared for indirect composite onlay with complete cusp coverage, using the burs from Indirect Style (Fig 3).?
Fig 3.?The set of burs for indirect restorations (Indirect Style).??? In the first stage of preparation, the depth grooves (Fig 4 a, b) were made on the occlusal surface in order to ensure sufficient space for the composite material (2.0 mm).?
Fig 4 a The depth grooves on the occlusal surface of the tooth 17?
Fig 4b ?The depth grooves on the occlusal surface of the tooth 17
Then the occlusal surface was leveled and the mesio-proximal contact point was released. The demineralized dentin tissues present inside the disto-occlusal crack line (Fig 5) were carefully removed (Fig 6), and the dentin was immediately sealed with bonding agent.
Fig 5 ?At the bottom of the crack line, demineralized dentin was visible.
Fig 6? The situation immediately after removal of demineralized dentin. The deepest part of the cavity was restored with fiber reinforced composite resin (Ever X Posterior, GC) in order to level the bottom of the preparation (Fig 7).
Fig 7 . ?The bottom of the crack line covered with fiber reinforced composite resin (Ever X Posterior, GC)???The aim of the dentin sealing with fiber composite resin material was also to stop the crack propagation, by means of short fibers incorporated in the material sub-structure.?An impression was taken with polyether precision impression paste (Impregum, 3 M ESPE) and sent to the laboratory in order to manufacture an indirect composite restoration. ?One week later the composite onlay (Enamel Plus, Micerium) was checked on the model and in the mouth of the patient, with regards to the color, marginal adaptation and contact point (Fig 8 a).
Fig 8 a?Indirect composite onlay fabricated in the laboratory (dental tech.: Roman Fr?czek)? The internal surface of the onlay was adhesively prepared by sandblasting with 50 µm aluminium oxide (Fig 8 b), followed by silane and adhesive application.
Fig 8 b ?The internal surface of the composite onlay, sandblasted with 50 µm aluminium oxide??
Tooth 17 was isolated with a rubber dam, and enamel and dentin were sandblasted with 50 µm aluminium oxide. Both enamel and dentin were etched (Fig 9), thoroughly rinsed with water spray, and dried delicately (Fig 10), and adhesive (EnaBond) was applied meticulously (Fig 11).
Fig 9.?Enamel and dentin were etched with orthophosphoric acid…
Fig 10? …then thoroughly rinsed with water spray, and dried delicately
Fig 11? … and adhesive (EnaBond) was applied meticulously.?? Composite onlay was cemented with light curing composite material (Enamel Plus, Micerium) heated to the temperature of 45-50 °C (EnaHeat, Micerium) (Fig 12).?
Fig 12 The indirect composite onlay was luted with light curing composite resin, heated to the temperature of 45-50 °C? ?All polymerized composite overhangs were removed with a scalpel, with the rubber dam in place (Fig 13).
The clinical situation after polymerization of the luting composite resin and overhangs removal. ?? After rubber dam removal, the restoration was checked for any occlusal and functional adjustments (Fig 14).?
Fig 14 ?The clinical outcome of the composite onlay after occlusal adjustments.? ?The patients follow-up appointment, one week later, did not reveal any pain and the pulp reaction was correct on the vitality test (cold). Because, an increased occlusal activity was suspected as the main cause of the tooth crack, the patient was scheduled for deprogrammation with a Kois Deprogrammer for four weeks. Then the occlusal equilibration was obtained in order to remove all premature contacts. Finally the patient received a Michigan maxillary occlusal splint according to Kois modifications for continuous use while sleeping period.
The 12-month follow up can be seen on Fig 15.
Fig 15 ?The 12- month follow up of the cracked tooth 17, restored with indirect composite onlay.