Large Amalgam Restoration UL6

The plastic restoration in the UL6 has failed. There is evidence of secondary caries undermining the enamel of the remaining mesiopalatal and distobuccal cusps. Cracks are also present within the enamel.

Flexidam [Coltene Whaledent] is applied and sealed with dental tape 

Amalgam Removal

The existing amalgam restoration is removed and an assessment of the cavity is made. There is gross caries together with evidence of a previous lining in the deeper portions of the cavity.

The cavity is disinfected with 5% NaOCl for one minute. This is to the reduce bacterial load prior to caries removal proper.

Caries Removal

The more heavily contaminated peripheral caries is removed. The precision of both hand and rotary instruments is improved under the microscope.

The cavity is periodically disinfected with 5% NaOCl to reduce the numbers of viable bacteria. Bur changes are made to avoid contamination of the deeper portions of the cavity with infected dentine.

A better assessment of the lining is now possible. It is felt that the lining covers a previous exposure.

Assessment Of The Cavity X10

With removal of the caries under X10 magnification the cavity is assessed. As anticipated the lining had been placed over the site of a previous exposure.

Note that the colour of the dentine does not reflect its state of demineralisation or infectivity.

Under the microscope: Tactile feedback through instruments is still required to assess the degree of demineralisation of the dentine.

Assessment Of The Dentinopulpal Complex X24

Under highest power a microexposure is revealed on the distoaxial wall of the cavity. There appears to be some limited blood supply to the fibrotic pulp associated with the distobuccal pulp horn. Coronal to this there are heavy tertiary dentine deposits [darker orange].

The distopalatal pulp horn is entirely occluded with tertiary dentine.

Pulp Biopsy

Following further disinfection with 5% NaOCL for one minute, with a sterile bur access is made to the pulp space.

The limited viability of the distobuccal pulp horn can be observed by the limited haemorrhaging from the pulpal tissues. The pulp occupying the palatal root canal is entirely avascular.

Without this level of magnification it is not possible to record the pulpal status. Clinical observation with the microscope dictate that this tooth undergo endodontic therapy.

Endodontic Treatment

With the diagnosis of a non-viable dentinopulpal complex, in preference to an unsuccessful pulp capping procedure, the UL6 is endodontically treated.

Note the presence of two mesiobuccal root canals with two distinct portals of exit.