Class I Cavity Preparation. Alaa Sabrah, BDS, MSD, PhD Nov,

Transcription

1 بسم اهلل الرحمن الرحيم Class I Cavity Preparation Alaa Sabrah, BDS, MSD, PhD Nov,

2 Goals and Objectives?Define class I carious lesion.1 Describe the clinical technique for treating class I?carious lesion.2 Describe the different steps of cavity preparation for.class I carious lesion for Amalgam restoration.3

3 Definition Class I (Pit and Fissure) - involves a pit or fissure on a posterior or anterior tooth

4 Grooves A groove is a linear channel on the surface of a tooth, usually at the junction of dental (lobes (cusps or ridges sulcus groove

5 Fissures A fissure is a developmental linear cleft, the result of incomplete fusion of the enamel of.adjoining dental lobes

6 Pit Pits are small pin-point depressions located at the junction of developmental grooves or at terminal of those grooves

7 ???????Why union failure of tooth lobes organic debris collects acid formation/ incubator effect area not self cleansing, eliminate geography susceptible tooth + bacteria+ food + time = caries toothbrush cannot reach bottom of groove

8 Caries Spread Diagram Pit and fissure Smooth Surface Enamel Dentin

9 :Indications Carious tooth structure in the occlusal fissures (or in facial or lingual pits) detected clinically and confirmed.with bitewing radiographs The replacement of a restoration that is defective beyond repair or associated with a recurrent caries.lesion

10 The objectives of treatment.to eliminate caries lesions To remove any enamel that has been undermined by.the caries process To preserve as much sound tooth structure as.possible To create a strong restoration that mimics the original sound tooth structure and allows little or no marginal.leakage

11 Clinical Technique Anesthesia (Pt comfort,.(decrease salivary flow Occlusal assessment (determine design, adjust.(the restoration function Isolation (visibility, better restoration.(quality.tooth preparation.pulp Protection.Restoration

12 G.V Black steps of cavity preparation Outline form Resistance form Retention form Convenience form Removal of remaining caries Finishing of walls and margins Cleansing of the cavity

13 Tooth Preparation Outline form.1 carious tooth (1) structure should be.eliminated margins should be (2) placed on sound tooth.structure

14 Tooth Preparation Outline form a bur (no.329 or 330) is used to cut through the enamel to gain access to.the carious dentin The preparation is widened to give access to all carious dentin and to remove any.unsupported enamel.no sharp angles Smooth Conservative.1 mm 1.6 Don t overextend prep into mesial or distal marginal ridges

15 Tooth Preparation When replacing a defective restoration (recurrent caries lesion), the outline form will be determined by The outline form of the old.restoration.additional carious lesion The resistance form.required.1.2.3

16 Tooth Preparation Resistance form.2 Adequate thickness for the restorative material Margins should be approximately 90.degrees Flat pulpal floor (resist forces directed in the.long axis of the tooth

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18 Tooth Preparation Retention form.3 opposing walls of Class 1 occlusal restorations should be parallel to each other or should converge slightly occlusally

19 Tooth Preparation :Convenience form Creating sufficient access to the carious lesion to :facilitate Visibility Instrumentation during cavity preparation and.restoration.4

20 Tooth Preparation Removal of remaining caries.5 Extension of the cavity should ensure that all caries has been removed.from the peripheral DEJ Best removed using spoon excavator or slow speed.round bur

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22 Tooth Preparation Finishing the walls and margins Finishing of the external walls and flares.6

23 FLARE terminal extensions: M/D/B/L parallel enamel rods to prevent fracture Retention will not be affected Retention is gained in central portion, bur design

24 Pulp Protection Cavity sealers Varnish Adhesive Sealers Cavity liners Cavity bases

25 .Direct Restorative Materials Amalgam Direct gold Composite resin (next (semester

26 Outline form of class I on different teeth

27 Outline form of class I on different teeth

28 Outline form of class I on different teeth

29 Outline form of class I on different teeth

30 Outline form of class I on different teeth

31 Amalgam Placement Set-up Assemble instruments Amalgam carrier, condensers, carvers, burnishers, explorer, and mirror Amalgam capsules and dappen dish Triturator

32 Amalgam Placement Check Triturator settings Place amalgam capsule in triturator properly and triturate

33 Amalgam Placement

34 Amalgam Placement Empty amalgam into dappen dish Load amalgam into carrier

35 Amalgam Placement Dispense amalgam into preparation Condense, pre-carve burnish, carve and post-carve burnish amalgam

36 Amalgam Placement Carve and post-carve burnish amalgam

37 Amalgam Placement Condense & pre-carve burnish

38 Amalgam Placement Evaluate completed amalgam restoration

39 Amalgam Placement Discard of excess amalgam properly If defective: remove immediately,use instruments or slow speed handpiece if necessary REMEMBER: newly set amalgam will cut very easily with handpiece

40 تم بحمد اهلل