Tooth wear Flashcards
What is the incidence of adults and children’s tooth wear?
Adults 77% have some form of wear anteriorly (2% severe)
> 50% children have wear on primary incisors
Describe attrition
Tooth to tooth contact parafunctional habits
Lesions on occlusal and incisal contacting surfaces
Early appearance of polished facet on cusp and flattening
Restorations show same wear as teeth
Describe abrasion
Wear of tooth structure through abnormal mechanical process independent of occlusion - foreign injection such as tooth brushing.
Site and pattern of tooth loss related to abrasive element
Manifests as notching on incisal edges with v shaped or rounded lesions o premolars and canines
Describe erosion
Tooth surface loss by chemical process that does not include bacterial action
Most common cause of tooth wear.
Enamel had loss of surface detail - flat and smooth
Exposed dentine causing cupping of occlusal surfaces of molars and incisal edges
Restorations stand proud on teeth
What are the differences of the clinical presentations of extrinsic and intrinsic erosion on the teeth?
Extrinsic:
- buccal surfaces of maxillary teeth and occlusal surfaces of mandibular posterior teeth
Intrinsic:
- palatal surfaces of maxillary dentition
- lower teeth are protected by tongue
Describe abfraction
Loss of hard tissue from eccentric occlusal forces leading to compressive tensile stresses at cervical fulcrum area of the teeth.
Cracks in tooth surface which causes tooth substance to chip out along with v shaped tooth loss where tooth is under tension.
Classical sharp rim at ACJ
What is the BEWE examination?
Score 0: no erosive wear
Score 1: initial loss of surface texture
Score 2: distinct defect, hard tissue loss <50% of surface
Score 3: hard tissue loss >50% of surface area
Risk level: None: less than or equal to 2 Low: 3-8 Medium: 9-13 High: 14+
What are the 2 commonly used indices for wear?
BEWE
Smith and knight index
What space is required in dentition for conventional crowns, adhesive on lays, adhesive veneers and composites?
Conventional PBC: 2mm
Adhesive on lays: 1mm
Adhesive veneers: 0.7mm
Composite: 1-2mm
What is the Dahl technique?
Technique used to gain inter occlusal space in cases of localised tooth wear without tooth reduction over period of 3-6 months.
Appliance is placed anteriorly increasing OVD by 2-3mm over time posterior teeth erupt into occlusion and anterior teeth then have space to be restored to normal height and new OVD.
When is the Dahl technique contraindicated?
TMJ problems Post orthodontic Tx Patients on bisphosphonates Dental implants Existing conventional bridges
What dental material has the best 5yr survival in class V cavities?
RMGIC as less moisture sensitive at gingival margin
