Isolation in Clinical Dentistry: Part-5

Fig. 3.137, 3.138: Secure the clamp with a long strand of floss tied on it. This helps prevent any accidental aspiration or ingestion. The floss should be tied and secured with several rounds (left), as with a single round (right) there is a possibility for the knot loosening up.

Fig. 3.139: Mark an ‘x’ on the 1st quadrant area of the dam sheet prior to punching holes. This helps maintain its orientation and avoids confusion when adapting the frame.
Fig. 3.140 shows properly punched holes on left and improper or incompletely punched holes on the right.

Fig. 3.142: Glycerine gel or any water soluble lubricant applied on the inner side of the rubber dam sheet or tooth helps to slip the dam sheet into interdental areas with ease.

Fig. 3.143-3.145: When using floss to push the dam sheet into tight interdental contacts, do not position the floss over the rubber dam sheet (top). Instead, pull the sheet either to the mesial or distal of the contact (middle, bottom) and then push it apically. This prevents the floss from causing an accidental tear in the dam sheet.

Fig. 3.146, 3.147: After the dam has been pushed interdentally, do not pull the floss out upwards, as this may cause the dam sheet to pull out with it. Instead, it helps to slide the floss along its length, either bucally or lingually. This ensures that the dam stays secure in its place.

Fig. 3.148, 3.149: A simple fold of dam sheet below patient’s nose can keep the airway free from obstruction by the dam sheet, thereby improving patient comfort and acceptance.

Fig. 3.150, 3.151: After removal from patient’s mouth, check the rubber dam sheet thoroughly against a light source (left), as small pieces can tear and remain stuck in areas of tight interdental contacts (right).

Fig. 3.152: As the name suggests, here one tooth alone is isolated from the rest of the hard and soft tissues of the oral cavity.

Fig. 3.153: Here an additional clamp is placed on top of the dam (without hole) on a tooth anterior to the one being treated. This improves orientation and access to the target tooth.

Fig. 3.154: Multiple tooth isolation.

Fig 3.155, 3.156: This is especially true for amalgam, which emits mercury vapors upon grinding. Additionally, secondary caries under amalgam restorations are often in close approximation with pulpal tissues and in the unfortunate episode of pulp exposure, rubber dam isolation helps protect the tooth from salivary contamination.

Fig. 3.157: To achieve this, a matrix band retained with an interproximal wedge is recommended

Fig. 3.158: Additionally, a ring can be used for building the correct proximal contacts and contours.

Fig. 3.159-3.162: In cases where the carious margin is very close to subgingival tissue, it helps to place the rubber dam clamp on a tooth distal to the one being treated. This allows for the matrix band to be positioned on the tooth in question with relative ease and without any interference from the clamp.

Fig. 3.163: If the case is suitable for DME, the rubber dam assembly is placed with the clamp on a tooth distal to the one being treated.
Fig. 3.164: Next, the gingival margin is retracted using a floss tie (explained on page 88). Teflon tape or retraction cord is used if the proximal gingival margin requires further retraction.
Fig. 3.165: Following this, all infected caries is carefully removed from the floor and adjacent walls using hand instruments (spoon excavator) and/or slow speed burs with utmost care to prevent iatrogenic pulpal exposure (if vital).
Fig. 3.166: The Automatrix or Garrison matrix is then adapted to the tooth. Next, wedge is placed interdentally, in order to secure the matrix band and to adapt it to the tooth while ensuring a leak proof margin.
Fig. 3.167: Regular bonding procedures are then performed to relocate the margin coronally.

Fig. 3.168, 3.169: Note the presence of a metal cast post and core assembly with sub-ginigval caries along the distal margin.

Fig. 3.170-3.172: In the double matrix technique, the first matrix should be stabilized first followed by the second matrix band that is placed inside the first one and pushed. Following this, Teflon is squeezed between the two matrices to seal the gap and provide pressure adaptation along the distal margin of the tooth.

Fig. 3.173, 3.174: Conventional bonding procedures are then undertaken to restore the missing distal wall.

Fig. 3.175-3.177: In situations where deep margin elevation is to be performed in conjunction with a surgical crown lengthening procedure, he rubber dam assembly is placed while the flap is still open. This provides the desired access and isolation to produce predictable results with relative ease. In this case, the matrix-in-matrix technique was used to restore the wall with composite and the tooth was subsequently restored with an overlay type prosthesis.

Fig. 3.178: A 212 clamp used for isolation of a lateral incisor showing sub-gingival defect from external root resorption. In such cases, where an external approach is used to repair the defect in conjunction with a muco-periosteal flap, absolute isolation is of paramount importance for a successful outcome. Teflon or gingival retraction cords should be used to improve isolation when indicated.

Fig. 3.179: In this case, a 212 clamp was sectioned and used to isolate the severely compromised left central incisor. Optionally, a number 0, 1 or B4 clamp can be used provided it can be stabilized over the tooth structure.