Temporary Teeth Caries Treatment

Uncomplicated Caries of Temporary Teeth: Treatment Overview

Treatmentfor uncomplicated caries in temporary teeth primarily involves restorative procedures. This entailsthe removal of all altered dental tissues affected by caries, followed by the application of an appropriate restoration material suitable for temporary teeth.

Class I Cavity Preparation forAmalgam

Class I cavities involve the pits and fissures on the occlusal surfaces of posterior teeth. Proper preparation is crucial for amalgam restorations.

Cavity Form and Outline:

• The cavity form must include all pits and fissures affected by caries.

• Enamel ridges (oblique and transversal) should bemaintained if they are not undermined, as this improves the tooth's resistance.

• Unsustainable enamel, meaning enamel lacking underlying dentin support, must be removed to prevent fracture.

• The cavity outline should besmooth and flowing, avoiding sharp or abrupt angles to distribute stress evenly.

Cavity Walls and Retention:

• The buccal (B) and oral (O) walls of the cavity should be convergent towards the occlusal surface. This angulation helps to improve the retention of the amalgam restoration.

• The mesial (M) and distal (D) walls of the cavity should be flat at the level of the marginal ridges. This ensures that the marginal ridges are not undermined, preserving their structural integrity.

Access and Depth:

• Creating access to the carious lesion can be done using diamond burs, specifically round burs, or a pear-shaped bur like the no. 330.

• The cavity depth should be 0.5 mm into the dentin, or approximately1.5 mm from the enamel surface. Burs such as the no. 330 or 169L are suitable for achieving this depth.

• Inverted cone burs are not recommended for cavity preparation in temporary teeth due to their aggressive cutting nature which can lead to pulpal exposure.

• The cavity floor should be slightly rounded or concave towards the occlusal surface. This helps in stress distribution and can be achieved using a no. 330 bur, a large-diameter spherical bur, or excavators.

Internal and Cavo-Surface Angles:

• All internal angles of the cavity should be rounded using spherical burs or excavators. Rounded angles reduce stress concentration within the tooth structure and amalgam.

• The cavo-surface angle, which is the angle formed between the cavity walls and the external occlusal surface, shouldideally be 90 degrees. This provides an optimal bulk of amalgam at the margin, enhancing its strength and durability.

Key Features of Class I Cavity Preparation:

1. Dentin depth: Approximately 0.5 mm.

2. Roundedangles: Internal angles should be smooth and rounded.

3. Concave floor: The pulpal floor should be slightly curved.

4. 90-degree cavo-surface angle: Essential for restorative material strength.

Extensions for Class I Caries:

• Buccal (B) or palatal (P) grooves and fossae with carious lesions may require extensions of the main Class I cavity outline.

• A dovetail extension may be employed for the palatal surface of an upper second molar.

• A tear-shape extension or ovoid extension may be used for the buccal surface of a lower second molar.

Class II Cavity Preparation for Amalgam

Class II cavities involve one or both proximal surfaces of posterior teeth and require a more complex preparation encompassingan occlusal cavity, a proximal cavity (the box), and an isthmus connecting them.

The Occlusal Cavity:

• The occlusal portion of a Class II cavity generally follows the same preparation rules as a Class I cavity.

• Maximum cavity depthshould be 1.5 mm to avoid pulpal involvement.

• Aim to create a single occlusal retention cavity, simplifying the preparation and restoration.

• Avoid excessive preventive extension to prevent weakening the tooth and potential fracture of thin walls.

• Supplementary retentionmethods are typically avoided in temporary teeth as they can compromise pulp vitality.

The Proximal Cavity (The Box/Vertical Cavity):

• The base of the proximal cavity should be larger than its occlusal opening to facilitate retention and removal of carious tissue.

• The vertical walls of the proximal box should ideally be convergent towards the occlusal surface for improved retention.

• The gingival wall should be slightly concave to follow the contours of the tooth.

• The preventive extension of the buccal and oral wallsshould reach the self-cleaning areas to prevent recurrence of caries.

• Ideally, the axial wall should be 0.5 mm into the dentin, providing adequate resistance form.

• The gingival threshold should be positioned at the level of the gingiva or slightlybeneath it, perpendicular to the long axis of the tooth.

• The gingival threshold should be slightly inclined towards the vertical parapulpal wall and have a mesiodistal (MD) depth of approximately 1 mm.

The Isthmus:

• The isthmus, which connects the occlusal and proximal portions of the cavity, should be broad to ensure sufficient bulk of amalgam for strength.

• An ideal isthmus width is approximately half () of the intercuspal width of the tooth.

• It is crucial to avoid an isthmus that is too narrow or has sharp angles, as these can create stress points leading to amalgam fracture.

Key Takeaways for Temporary Teeth Caries Treatment

• Restorative treatment is the standard approach, involving meticulous removal of carious tissue.

• For Class I cavities, emphasis is on including all pits/fissures, maintaining enamel ridges, smooth outlines, convergent walls for retention, and specific depth guidelines.

• Burs like no. 330 are frequently used; inverted cone burs are contraindicated.

• Rounded internal angles and a 90-degree cavo-surface angle are critical for amalgam longevity.

• Class II cavities require careful coordination between the occlusal and proximal components, with the proximal box having specific parameters for walls, floor, and gingival threshold.

• The isthmus must be sufficiently wide (ideally half the intercuspal width) and free of sharp angles to prevent fracture of the restoration.