Prof. Asaad Javaid BDS, MCPS,MDS Dept of Restorative Dental Sciences College of Dentistry, Alzulfi Majmaa University

, Non Carious Tooth Defects

Learning objectives Describe meaning of non carious tooth defects List various non carious tooth defects Define and identify amelogenesis and dentinogenesis imperfecta Describe and identify non hereditary enamel hypoplasia

Learning objectives Define tooth wear Describe various terms used in tooth wear List causes of attrition, abrasion, abfraction and erosion Describe clinical problems associated with tooth wear

Definition Defects which are present in mineralized tissues of a tooth congenetically or produced later in life else than carious defects

Types Developmental Traumatic Wear

DEVELOPMENTAL TOOTH DEFECTS

Amelogenesis imperfecta It causes teeth to be small, discolored, pitted or grooved and prone to rapid wear and breakage It can affect primary & permanent dentition

Dentinogenesis imperfecta It causes discoloration (blue-gray / yellow-brown) & translucency Teeth are weaker and prone to rapid wear, breakage, and loss It affects primary & permanent teeth Normal enamel attaches to defective dentine

Non hereditary enamel hypoplasia Enamel defect that results due to less than normal amount of enamel The missing enamel is localized, which results in small dents, grooves or pits on surface of affected tooth It makes the tooth surface very rough, and the defects are visible for being brown or yellow

Non hereditary enamel hypoplasia

TRAUMATIC TOOTH DEFECTS

Incomplete fracture An incomplete fracture not directly involving a vital pulp is termed a greenstick fracture This condition is very sensitive & patient can specify affected side of the mouth rather than affected tooth

Complete fracture A complete fracture not directly involving vital pulp Usually, pain is not associated with this condition unless the gingival border of the fractured segment is still held by periodontal tissue

Fracture involving pulp This condition always results in pulpal infection and severe pain If the tooth is restorable, immediate root canal therapy is indicated; otherwise the tooth should be extracted

TOOTH WEAR DEFECTS

Definition Wear is a natural process that occurs whenever two or more surfaces move in contact

Pathological tooth wear Normally, tooth surface loss does not need any treatment if its cause is removed on time otherwise level of wear becomes pathological and requires operative intervention

Reduced vertical height

Change in teeth appearance

Long term viability Tooth which have risk to long term viability due to progressive destruction

Pulp involvement

High wear rate Accelerated and high wear rate relative to age

Loss in posterior occlusal stability resulting in a- Increased tooth wear b- Mechanical failure of teeth restorations c- Hypermobility and drifting

TMJ dysfunction TMJ pain is a cycle of soreness and muscle spasms that occurs if bite is not aligned or if patient clenches or grinds the teeth People under stress clench and grind their teeth, either consciously or unconsciously Bruxism increases wear on TMJ and intensify pain

Interchangeable terms The terms “ tooth surface loss”, “tooth wear” and “worn out dentition” non- carious tooth loss” are interchangeable and embrace all the etiological conditions that cause tooth wear which occur in the absence of dental plaque and caries and trauma

Attrition It is mechanical wear of the incisal or occlusal surface as a result of functional or parafunctional movements of the mandible (tooth-to-tooth contacts) Attrition also includes proximal surface wear at the contact area because of physiologic tooth movement

Clinical features Affect primarily occlusal and incisal surfaces and proximal surfaces Well defined flattening of cusp tips and incisal edges and localized facets on occlusal or palatal surface are seen

If dentin involved if erosive factor is present, ‘cupping”or “grooves” form in the dentine The severity increase with age

Attrition of lower incisor teeth that meet palatal surfaces of maxillary incisors in excursive movements

Causes Parafunctional habits Developmental defects Coarse diet Lack of posterior support

LONGEST ENGLISH WORD FLOCCINAUCINIHILIPILIFICATIONISM

Abrasion Abrasion is abnormal tooth surface loss resulting from direct friction between teeth and external objects, or from friction between contacting teeth components in the presence of an abrasive medium

Causes 1- Vigorous horizontal tooth brushing 2- Nail biting, pen biting and pipe smoking 3- Denture clasps 4- Abrasive dentifrices 5- Hard tooth brushes

Clinical features “V” shaped cervical lesion Affect labial surfaces of prominent teeth, eg. Canines May affect teeth in the left side of right handers and vice versa

Abrasion Lesions

Abfraction It is a non carious cervical lesions caused by tensile stress generated from occlusal loading, and microfracture of cervical enamel rods Also known as “Idiopathic Erosion”

If occlusion is not ideal or if heavy occlusal trauma is present, significant lateral forces are generated, which cause the tooth to bend and create compressive and tensile stresses on tooth structure. The region under greatest tensile stresses is the fulcrum located around the cementoenamel junction. Tensile forces disrupt chemical bonds between hydroxyapatite crystals in enamel. MECHANISM

Pivot Point Forces working on teeth at any time

The stress corrosion theory is supported by number of observations: 1- Evidence of tensile forces created in cervical region 2- A high incidence in bruxist 3- Lesions can be found on only one tooth in one segment 4- Lesions found in subgingival regions

Abfraction lesion located subgingivally

Erosion Erosion is the progressive loss of hard dental tissues by chemical process not involving bacterial action

Causes 1- Dietary 2- Regurgitation 3- Environmental 4- Flow of saliva 5- Medications

Dietary erosion Citric acid in soft drinks and fruit juices Slimness: acidic sugar free drinks “Healthy eating”: fruits

Regurgitation Involuntary regurgitation: 1- gastrointestinal problems 2- Chronic alcoholism Voluntary regurgitation 1- Anorexia nervosa 2- Bulimia nervosa

Environmental Tooth wear caused by acid exposure in the environment or under occupation circumstances such as battery-making workers, picklers, miners Usually affect labial surfaces of maxillary and mandibular incisors

Saliva flow rate Saliva has a buffering and lubricating effect Reduced flow and rate: Xerostomia, Sogren syndrom, radiotherapy

Medicine Ascorbic acid tablets, Aspirin tablets, Effervescent vitamin C preparations, Medication that reduce salivary flow such as tricyclic antidepressants and antihypertensive

Clinical Features : Rounded less well defined margins than attrition Enamel has matted surface Dentine may be exposed with continuous erosion (Cupping) Palatal erosion related to intrinsic and extrinsic acids Increase in translucency of anterior teeth Cervical surfaces may be more prone to erosion because these areas close to the gingiva are less self- cleaning and food and beverages may be harboured on the tooth surface for longer periods of time

Bulimic patient Erosion of palatal surfaces

Clinical Problems associated with tooth wear Aesthetics loss of tooth structure Sensitivity and pain Inter-occlusal space: dento-alveolar compensation occurs in 80% of patients with tooth wear. I.e, free way space and resting facial height unaltered Patient compliance and expectations

Wear associated with bulimia

Management Immediate Therapy: Aimed to: 1- relieve sensitivity and pain 2- Identify aetiological factors 3- Protect remaining tooth tissue Aims can be achieved by: Diet analysis and counseling Consumption of erosive beverages in a proper manner Prescription of neutral sodium fluoride mouth rinse or gel Close fitting occlusal splint Restoration with composite or glass ionomer

Cervical Tooth Wear Management Not all lesions require restorations Restore if esthetic, sensitivity or structural concerns prevail Composite vs. glass ionomer. Lesion margins in enamel-microfine composite Lesion margins involve cementum or dentine-Dentine bonding with composite or GIC Deep cervical lesion-layered technique (GIC and composite)

Repaired with composite