Horizontal crack in molar

Root fractures,[ 3 , 48 ] which are often catastrophic fractures,[ 49 ] can result from caries in root structure or from roots containing intra-canal retainers[ 2 , 50 ] where the tooth lacks ferrule tooth structure, which results in a post putting more stress on the root. One study[ 53 ] showed that the volume and weight of roots are greater factors for increasing root fracture resistance compared to the mesial-disal or buccal-lingual dimensions of roots.

If a dentist decides to permanently restore a cracked tooth with a direct restoration,[ 24 , 58 , 59 , 60 , 61 ] the dentist may want to adjust[ 62 , 63 , 64 ] the bio-mechanical circumstances of the tooth to increase the tooth's resistance to further cracking. If the dentist decides to crown[ 65 , 66 ] the tooth, the dentist may also want to adjust the tooth to stabilize the tooth bio-mechanically in the days or weeks prior to the crown preparation appointment.

Such stabilization may be accomplished by reducing, on the cracked tooth, the steep inclines[ 67 ] of any nonfunctional or guiding cusps that are in deep overbite with opposing teeth ideally without exposing dentin , or smoothing the pointy plunger cusps of opposing teeth that are occluding into the cracked tooth, to reduce tensile forces on the tooth.

The dentist should maintain the overjet of the maxillary posterior buccal cusps with the mandibular posterior buccal cusps, to prevent cheek-biting that may result from lack of overjet.

Ideally, centric contacts should not be removed with such adjustments since this may result in other teeth in the arch re-equilibrating to a different occlusal force distribution.

Furthermore, if the opposing tooth occludes only into the cracked tooth, removing centric contacts may induce the opposing tooth to extrude back into occlusion with the cracked tooth. If a partially fractured tooth is not in occlusion or is opposed by a denture tooth, the tooth may last indefinitely.

If the patient is young, relatively few years may have been required until an observed fracture plane developed, implying a faster rate of fracture propagation, potentially justifying crown treatment. A tooth may present with a cusp fractured off and a large restoration that occupies most of the marginal ridge areas and the tooth structure occlusal to the pulp chamber roof [ Figure 9 ].

Here, the natural tooth structure was unable to accept the force load of retaining the restoration without developing a cusp fracture; with the cusp gone, the remainder of the tooth must now accept a larger force load to retain the restoration, which may eventually result in another cusp fracture. A radiograph may show a restoration that is deep in an occlusal-to-apical direction [ Figure 11 ], where there is minimal height of tooth structure from the gingival interface level of the tooth to the apical level of the restoration.

A crown and possibly a post may be needed to retain the supra-gingival restoration. However, if the restoration has a buccal or lingual component that reaches the CEJ area of the tooth, then the restoration, on the radiograph, may appear deeper than it is in reality. A radiograph of a maxillary molar that contains minimal remaining coronal tooth structure that can help to retain the large mesial-occlusal-distal restoration.

The remaining tooth structure is under higher stress levels from retaining the restoration. Part of the distal aspect of the remaining tooth structure fractured, showing that the remaining tooth structure is not strong enough to retain this direct restoration without developing cracks. A dentist may be tempted to drill out a crack line until the dentist has reached healthy tooth structure, and then place a direct restoration, to seal the tooth structure.

However, a crown may be needed to prevent the original causes of the crack from causing further crack propagation. Such crack line drilling should be done with a thin bur to ensure a conservative, narrow drilling width that preserves dentin, with microscopes ensuring that the dentist does not drill past the apical extent of the fracture plane. A crown prevents flexure of weakened supra-gingival tooth structures thereby slowing or stopping the rate of fracture plane expansion , by transferring the stresses of occlusal forces to the cross section of tooth structure circumscribed by the margin of the crown; this cross section subsequently resists occlusal forces.

Various categorizations[ 5 , 36 , 44 , 70 ] and terminologies[ 1 , 10 , 13 , 37 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 ] have been proposed to describe the phenomenon of cracked teeth. There is no universal agreement among dentists concerning which of these descriptive systems is definitively correct,[ 83 ] perhaps due to the inconsistency of symptoms and the seemingly random shapes of fracture planes as they appear clinically.

This article proposes describing cracked teeth based on what structures are intersected by stress planes or fracture planes. A comprehensive review of all of the historical descriptions is beyond the scope of this article, although a few comments are presented here. Furthermore, cracked teeth symptoms are inconsistent,[ 15 , 18 , 84 , 85 , 86 , 87 ] a fact that Cameron acknowledged. This information is arguably best provided by describing a cracked tooth stress plane based on what tooth structures a partial fracture of that stress plane intersects or would intersect if the stress plane completely fractured.

Microscopes facilitate observation of microscopic crack lines that may show minimal color contrasts against a desiccated tooth surface [ Figure 12 ], without needing trans-illumination or dyes to observe crack lines. Microscopically precise tactile sensation permits verification of a crack by associating the tactile sensation of an explorer tip falling into a cleft with the microscopic point on a crack line where the tip is located.

Microscopes permit detecting microscopic amounts of debris in the cleft,[ 5 ] or microscopic differences, in the respective directions of movement, of separate tooth structures shifting independently of one another around a cleft [ Figure 13 ]. Stripping a microscopically thin layer from a surface with a deep craze line may reveal uncracked underlying tooth structure, indicating that the crack is superficial. A sensitive premolar shows a cleft and a microscopically thin crack line, with a minimal color contrast with surrounding tooth structure.

Microscopes permit accurate visual estimation of the steepness of cuspal inclines, and allow precise observation of where a pointy lingual plunger cusp occludes into an opposing tooth, and observation if a microscopic crack line is developing around this contact area.

Microscopic amounts of chalky white or beige discoloration underneath a cusp can be indicative of caries under the cusp, which sometimes can be overlying a fracture plane. Microscopes facilitate observing microscopic gaps or elevations of restoration margins, which may indicate cracks. Microscopes improve the ability to understand the dimensions of foreshortened surfaces. This facilitates observing a marginal ridge crack from an occlusal viewing vantage point, to assess how closely to the gingiva the crack has propagated.

Using microscopes and co-axial illumination, a dentist may drill an exploratory column through a crack line, to observe the depth at which the crack line disappears, or to assess if the crack line extends into the pulp chamber roof. Sometimes, such exploratory drilling may be necessary to allow a dentist to discover that an asymptomatic tooth has a fracture plane that extends into the pulp chamber.

Discovering this allows a dentist to diagnose that this asymptomatic tooth has a necrotic nerve. Although such exploratory drilling is not necessarily superior to thermal, and electric pulp testing for diagnosing a necrotic nerve, such exploratory drilling may be a useful diagnostic adjunct if the thermal and electric pulp testing results are inconclusive.

If a fracture plane extends into the pulp chamber floor, this could hinder endodontic sealing of the chamber, although endodontic treatment may last indefinitely. If the fracture plane clefts the pulp chamber floor, the fracture may be catastrophic. The periodontal and biomechanical prognoses of a cracked tooth depend on what aspects of the tooth structure are intersected by a partial fracture of a stress plane, or would be intersected if the stress plane completely fractured [ Table 1 ].

The dentist should assess if the fracture plane seems to be expanding at a rate that is fast enough to justify crowning the tooth in the near future, if a crown is needed to stop the factors that seem to be causing fracture plane expansion, if the tooth would be biomechanically stable after crowning, and if an endodontic procedure is needed and is capable of hermetically sealing the cracked tooth. Source of Support: Nil.

Conflict of Interest: None declared. National Center for Biotechnology Information , U. Journal List Eur J Dent v. Eur J Dent. John S. Mamoun 1 and Donato Napoletano 2. Author information Copyright and License information Disclaimer. Correspondence: Dr. Mamoun Email: moc. This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3. This article has been cited by other articles in PMC. Abstract This article reviews the diagnosis and treatment of cracked teeth, and explores common clinical examples of cracked teeth, such as cusp fractures, fractures into tooth furcations, and root fractures.

Keywords: Crack propagation, cracked tooth syndrome, microscopes, tooth fractures. Open in a separate window. Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. A molar with a class II restoration and a crack in the untouched marginal ridge. Figure 6. This maxillary molar with a class II restoration was sensitive.

Figure 7. CUSPAL STRESS PLANES A cuspal stress plane is a stress plane, the perimeter of which is located approximately apical to one cusp, or apical to two or more connected cusps, where the axial aspect of the stress plane may intersect the pulp chamber walls or roof but does not intersect the pulp chamber floor , and where the lateral aspect of the stress plane intersects the external buccal or lingual tooth surface, and possibly a root, and may be located subgingivally.

Figure 8. Figure 9. Figure A periodontal probe in the premolar separates the cracked piece. Table 1 Crack types and possible treatment choices. Footnotes Source of Support: Nil. Ellis SG. Incomplete tooth fracture — Proposal for a new definition. In 85 percent of the teeth, this healing remained unchanged throughout the control period with no post-healing complication. At 10 years there was an 80 percent survival rate.

The highest frequency of tooth loss 70 percent was with teeth that had cervical fracture locations. So, if you remove the teeth with cervical fracture locations, the year success rate rose to 88 percent. This finding makes sense if you consider that the nearer the fracture is to the osseous crest, the less root is present in bone to support the crown of the tooth.

Looking at the image below, we can see that the fractured central incisor is still functional and serviceable at 13 years. Click this link to read more dentistry articles by Dr. Gregg Kinzer. The crack may extend through one marginal ridge or may extend through both proximal surfaces. The vertical depth of the crack is also variable. The crack may be entirely contained within the crown of the tooth, or it may extend vertically into the root portion of the tooth. A cracked tooth is more centered, occlusally, than a fractured cusp.

Also, because a cracked tooth may progress apically, rather than laterally, there is a greater chance of pulpal and periapical pathosis.

The location and extent of the crack may be difficult to determine. Some cracks are easily seen with magnification, or because they are stained from bacterial migration. Additionally, some cracks are identified with a dental explorer because they have caused a true separation of the enamel. However, the extent of the crack on the surface enamel does not correlate directly to the extent of the crack apically. Patient symptoms are variable, as well.

Others will not exhibit any symptoms. Excessive occlusal forces are a contributing factor to creating tooth cracks. Weakened tooth structure from existing restorations also contributes to tooth cracks. Undermined cusps and marginal ridges create an environment for cracks to occur. Removal of old restorations is recommended for evaluation of crack extent and depth. There are numerous diagnostic tests available for cracked tooth situations.

Removing old restorations in the presence of a crack is a starting point. Magnification is paramount for aiding in evaluation of the extent of the crack. The crack may be visualized extending along the pulpal floor from mesial to distal. This is a pathognomonic sign of root fracture to be discussed next.

Pulp vitality and patient symptoms will aid in determining the extent of the crack. Tooth cracks are highly variable in extent and symptoms. Cracked tooth treatment is variable and is dependent on crack extent, operator experience, judgment and patient symptoms.

There are no definitive restorative recommendations in the literature about treatment of cracked teeth. Proper diagnosis and preventive strategies are recommended for the treatment of cracked teeth. Obviously, root canal treatment is possible if pulpal and periapical symptoms dictate need. But cracked tooth treatment may be as limited as replacement of a direct restoration to full or partial cuspal coverage. Depending upon the crack extent and depth and structural integrity of the remaining tooth, the restoring dentist must decide what mode of treatment is appropriate.

The dentists experience will play a role as to whether or not and to what extent the cracked tooth is maintained and restored. Cracked tooth prognosis is always questionable.

There is always the possibility that the crack will progress, even if cuspal coverage is performed. Limiting the amount of tooth flexure is the goal with bite adjustment and cuspal protection.

But the micro-movement of tooth function can contribute to crack propagation over the long term. Not all cracked teeth are destined to fail. But depending on patient circumstances, occlusal stability and patient cooperation, a cracked tooth may eventually fail. Removing damaging habits for example, by providing a night guard and controlling bruxism , covering cusps and counseling patents on the variability of cracked tooth treatment are recommended preventive strategies.

In cases of cracked teeth, the patient should be informed of the questionable prognosis associated with this condition. It typically extends through both marginal ridges and the proximal surfaces to the proximal root.

A split tooth is the end result of a cracked tooth evolution! The tooth segments are entirely separated. The split may occur suddenly, but is typically the result of the long-term growth from an incomplete crack.

Again, damaging habits, such as bruxism, parafunction, ice chewing, etc. I would have thought for sure to extract the tooth. Thanks for going through this case, very informative. Yes I did irrigate with sodium hypochlorite and in this case, there was no mobility. But, yes I would expect it to decrease. Irrigation should always be delicate. Hi Sonia, Thank you for this blog.

I am learning so much endo from you that I never did in any of the seminars I had attended before. Thank u for sharing your knowledge with us. Keep going! Is there anyway to save it? I can attach xrays for yr reference. I am sorry that you are going through this. Unfortunately, this needs a thorough examination that I cannot provide you at this time.

Please seek out a consultation from a local endodontist if you still have questions. Hello doc! In cases of horizontal root fracture how would one be able to know if composite and wire splinting or intraradicular splinting would work better? Hey there! You always want to use a physiological splint, so I always use a fishing line! Hello Sonia, I am scheduled to remove my front tooth next week and replace it with a dental implant. My dentist noticed a horizontal fracture at the root of my crowned tooth.

I experienced pain along with a bubble just above the tooth on my gumline a year ago. I was treated with an antibiotic then sent to an endodontist. The endodontist sent me to a periodontist who says removal is my only option. I have no pain whatsoever.

The antibiotic cleared the infection. My dentist and the periodontist said the infection has not gone away because the sore on my gum line is still present. They all said the only way to get rid of the infection is to remove the tooth where the source of infection is. I have no pain and the tooth is stable. Can it be saved in your opinion?

Can I just do nothing? They mentioned the longer I wait I risk bone loss. Please help me. Hi there. Unfortunately, without the proper data, I cannot help you adequately.