Notches on Teeth: Evaluation and Treatment of Non-Carious Cervical Lesions

John J. Maggio, DDS Clinical Assistant Professor Department of Restorative Dentistry SUNY at Buffalo, School of Dental Medicine [email protected]

CHARACTERISTICS OF NON-CARIOUS CERVICAL LESIONS

Two general shapes:

WEDGE SAUCER

from Aw et al, 2002

- Concave, with no sharp angles. - Angular, V-shaped, with flattened floor. - The V-shaped lesions seem to be more prevalent. - These two lesions may have different causes and processes.

1 Research shows that: • NCCL’s occur in 5% to 85% of patients. • The first premolar is the most affected . • Two thirds of lesions are found in the maxilla. • The average lesion is 1 to 2 mm deep.

These lesions: • increase in size with age • increase in number with age • are found more often on FACIAL surfaces than LINGUAL surfaces

IMPLICATIONS & SIGNIFICANCE OF NON-CARIOUS CERVICAL LESIONS

These lesions can affect - tooth sensitivity - plaque retention - caries incidence - structural integrity - pulp vitality

ETIOLOGY OF NON-CARIOUS CERVICAL LESIONS

Why is it important to know what causes these lesions? 1. Knowing the cause could help us slow progression of current lesions and prevent new ones. 2. Knowing the cause could help us decide how/if to treat them.

UNTIL WE KNOW OTHERWISE, WE HAVE TO ASSUME THAT WHATEVER CAUSED THESE LESIONS IS STILL CAUSING THEM.

OCCLUSION / ABFRACTION & NON-CARIOUS CERVICAL LESIONS abfraction = “breaking away”

Brandini et al, 2012: There was a correlation between NCCL’s and: - tooth clenching - nail biting - TMD diagnosis Maxillary premolar NCCL’s were associated with tooth clenching. Mandibular canine NCCL’s were associated with nail biting.

2 TOOTHBRUSHING & NON-CARIOUS CERVICAL LESIONS

TOOTHBRUSHING FACTORS COULD INCLUDE: • Frequency • Forcefulness • Faulty technique • Filament stiffness • Abrasive - We have probably overemphasized bristle stiffness and underemphasized toothpaste abrasiveness.

ACID EROSION & NON-CARIOUS CERVICAL LESIONS

- “Biocorrosion” is a more accurate term than “erosion”. - This phenomenon is more complex than originally thought. - Acid erosion is classified as: - Intrinsic • Bulimia • Reflux • Regurgitation - Extrinsic • Occupational acid exposure • Carbohydrated soft drinks • Fruit juices - Any food or drink with a pH lower than 5.5 can demineralize teeth. - EROSION CAUSED BY FOOD & DRINK: • most commonly affected are the labial and lingual surfaces of the maxillary anterior teeth • A drink is carried on the tongue and pressed against the palate during swallowing. Therefore lower teeth are shielded. • The erosive effect of a drink is short-lived (a few seconds, as opposed to 30 min for caries). • Saliva stimulated by the drink neutralizes whatever remains on the tongue in a few minutes. • To prevent erosion, the drink would have to be chased with water within 30 seconds. • As the drink is sipped, the erosion continues. • “Diet” drinks with no fermentable carbohydrates cause erosion, but not caries. EROSION AND : • Fluoride cannot remineralize eroded tooth structure. • Fluoride cannot prevent erosion. EROSION AND DRY MOUTH: • A reduced salivary flow is an aggravating factor. • Without healthy buffering, acid will remain longer. • Drinking, and sipping, should be assumed to be very erosive in these patients.

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. Wear from occlusion Erosion creates occurs in a plane, sharp, chipped with shallow dentin enamel edges, wear, often in the and deeply direction of cupped dentin on tooth-to-tooth incisal or occlusal movement. surfaces.

THE MULTIFACTORIAL NATURE OF NON-CARIOUS CERVICAL LESIONS Litonjua et al, 2003: The authors recommend the term “NONCARIOUS CERVICAL LESION” (NCCL), since “erosion”, “” and “abfraction” imply a single etiology, which is most likely not the case.

Aw et al, 2002: - NCCL’s appear to have a multifactorial etiology. - Any one of the three (erosion, abrasion, abfraction) can be the catalyst, with the others contributing synergistically. - One of the three may be the predominant factor, depending on the patient.

These mechanisms can occur - synergistically, - sequentially, OR - alternately

EXAMPLE Erosive cervical lesions could be worsened by tooth brushing. If the patient bruxes, or has an occlusal interference, the lesions now become Corrosive-Abrasive Abfractive.

IDENTIFYING & MANAGING ACID IN NON-CARIOUS CERVICAL LESIONS

ACID SCREENING AND COUNSELING: 1. INTRINSIC - Ask if patient ever has, or has had, stomach acid in their mouth. - Ask GERD patients if they take their medication. - Ask patients who claim no GERD if they have ever been tested. 2. EXTRINSIC - Ask patient if they have any occupational exposure to acid. - Ask about diet. - Include drinks AND foods. - Include foods/drinks patients might not think are acidic. - Focus on number of exposures and exposure time. - Recommend drinking with a straw. - Avoid tooth brushing for one hour after acid exposure.

4 MANAGING TOOTHBRUSHING & NON-CARIOUS CERVICAL LESIONS

TOOTHBRUSH SCREENING AND COUNSELING: 1. “Show me how you brush.” Correct a “horizontal” technique. 2. “How hard do you brush?” Teach gentle, circular motion. 3. “How often do you brush?” Advise patients on frequency. Use only water after two times? 4. “Do you use a soft, medium or hard ?” Ask patient to switch to soft, but advise that it’s not enough. 5. “How much toothpaste do you use?” Teach “pea-size”. 6. “Where do you start brushing?” Recommend alternating, OR Recommend beginning with occlusals.

There is no correlation between forceful brushing and plaque removal.

MANAGING OCCLUSAL FACTORS IN NON-CARIOUS CERVICAL LESIONS

OCCLUSAL SCREENING AND TREATMENT: 1. Ask about “biting” habits 2. Ask about clenching/grinding 3. Ask about TMD pain 4. Examine occlusal scheme 5. Look for wear facets 6. Mark static and excursive contacts 7. Occlusal adjustment? 8. Occlusal Splint?

INDICATIONS FOR RESTORATION OF NON-CARIOUS CERVICAL LESIONS

The recommendation to restore a tooth affected with a NCCL should depend upon the following factors: • Inability to eliminate or greatly reduce the rate of lesion progression through elimination of etiologic factors • Esthetic unacceptability of the lesion to the patient • Hypersensitivity to mechanical stimulation, cold liquids, food, and air • Threat to the strength and integrity of the tooth because of the lesion's depth • Food or plaque trap • That area will receive a partial denture clasp • High caries risk patient

5 RESTORATION OF NON-CARIOUS CERVICAL LESIONS - These lesions are CHALLENGING to restore. - These restorations are the LEAST RETENTIVE.

RESTORATIVE CHALLENGES: • subgingival extent • difficult to isolate • gingival margin on dentin

NCCL’s are challenging to restore: - restoration loss - gingival excess - recurrent caries

AMALGAM & NON-CARIOUS CERVICAL LESIONS Amalgam is of little use in restoring NCCL’s.

RESIN COMPOSITE & NON-CARIOUS CERVICAL LESIONS RESIN COMPOSITE CHALLENGES • (sub)gingival extent • difficult to isolate • not much enamel to bond • gingival margin on dentin • sclerotic dentin

FLOWABLE COMPOSITE: - Flowable composites exhibit more voids and bubbles and more microleakage than conventional composites. - A flowable composites must be used with a compatible bonding agent. - It is a good idea to use a flowable composite and a conventional composite from the same company/product line. - Flowable resins as liners have not be shown definitively to improve the clinical performance of a resin composite restoration.

ADHESIVE TYPE:

Clinical dentin bonding studies are performed on NCCL’s: - There is not much enamel to bond, so the bond to dentin is being tested. - The preparation is not retentive, so the bond to dentin is being tested.

In clinical bonding studies: - Dentin is not roughened. - No retention is placed. - No bevel is placed.

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- Clinical studies show that composite restorations of NCCL’s utilizing three-step etch-and-rinse adhesives (4th generation) have the best retention. - Many studies show that the next most retentive adhesive for these lesions is the two-step self-etching adhesive (6th generation). - The BEST retention in NCCL’s is RESIN-MODIFIED GLASS IONOMER. - For self-etching adhesives, “Selective acid-etching of the enamel margins enhanced the performance of the two-step self-etch adhesive in terms of marginal discoloration and marginal adaptation at the enamel side.” (Can Say et al, 2013)

TIPS FOR COMPOSITE IN NCCL’S 1. Consider placing a wide bevel. 2. If you are using an etch-and-rinse adhesive, etch well beyond the lesion. 3. If you are using a self-etching adhesive, consider selectively etching the enamel. 4. If possible, use a rubber dam. 5. Use a #12 scalpel - NOT a handpiece - to trim the gingival margin. (A scalpel is the safest option for the gingiva, the root and the margin.)

The preferred restorative approaches in order (for NCCL’s) are: - RMGI - RMGI liner, with composite overlay - Composite with bonding agent (Tyas, 1995)

7 GLASS IONOMER & NON-CARIOUS CERVICAL LESIONS Glass ionomers have better retention rates than composite, but all other qualities are better with resin composite.

GLASS IONOMER ADVANTAGES • coefficient of expansion close to tooth structure • low setting shrinkage • inherent chemical bond to enamel & dentin • good marginal sealing • little microleakage • good retention rates • have the best retention for nccl’s (RMGI) • biocompatible • cariostatic

GLASS IONOMER WEAKNESSES • technically demanding • very sensitive to changes in water content • short working time • long setting time • margins look inferior to resin and amalgam • not as polishable as resin and amalgam • wear more than resin and amalgam • not as esthetic as resin

WHY USE A CONDITIONER? 1. The weak acid removes the smear layer, allowing the chemical bond to occur. 2. Mild demineralization creates micro-porosities and increases surface area. 3. “ phase” formation: Polyalkenoic acid reacts chemically with hydroxyapetite to form tags.

GLASS INOMER HANDLING: MOISTURE - Don’t over-dry prep before placement. - Keep field free of excess water while placing. - Don’t dry while finishing. - Coat with a sealer after polishing. - Don’t dry a glass ionomer while evaluating it.

While placing a glass ionomer material: 1. The material should be injected in way that provides close contact with the tooth. 2. The material should only be manipulated while it is still shiny and flowable. 3. If the material becomes dull and hard and begins to pull away from the preparation, it should be removed and replaced.

8 RMGI ADVANTAGES OVER CONVENTIONAL GI • longer working time • set on demand (light) • less sensitive to water • better compressive, tensile & flexural strengths • better wear resistance • better marginal adaptation • even less microleakage • more esthetic • just as much fluoride release & recharge

While manipulating a glass ionomer material: 1. You can clean your instrument with WATER or ALCOHOL, but you should not contact the material with water or alcohol, as they can destroy the chemistry of the material. 2. You could place a small amount of the GI sealer on your instrument to avoid sticking to the material.

SANDWICHES & NON-CARIOUS CERVICAL LESIONS

TISSUE MANAGEMENT FOR NON-CARIOUS CERVICAL LESIONS - rubber dam - retraction cord - (electrosurgery / laser) - flap surgery

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