There is evidence for association between dental infection and several systemic conditions including: central and peripheral vascular disease, diabetes, poor birth outcomes and aspiration pneumonia.1–6 Although mechanisms are unclear, some animal and human intervention studies suggest a causative contribution of oral infection to these systemic conditions,2,7–14 so that improved control of dental infection may reduce the burden of separate systemic disease. Dental infection also contributes substantially to preventable hospitalisation.15,16 Despite these broad health implications, dental services are not included in Australia's Medicare universal health insurance system, and the cost of private dental services significantly limits access.17
In November 2007 the Enhanced Primary Care Dental Initiative, which provided limited dental funding, was expanded to become the Medicare Chronic Disease Dental Scheme (CDDS). Under the CDDS, eligible patients may receive Medicare benefits of up to $4,250 for eligible services provided under the CDDS during two consecutive calendar years. Eligibility for CDDS is determined by general medical practitioners, who identify the presence of a chronic systemic disease that may be adversely affected by the patient's dental condition. Medical practitioners are required to prepare multidisciplinary care plans including dental treatment, in order for patients to access the CDDS.
Although the Federal Government elected in December 2007 indicated cessation of CDDS, the scheme has continued with the support of the Senate. The public availability of data on CDDS service provision provides an unprecedented opportunity to examine patterns of private dental service heavily subsidised by the Australian Federal Government via Medicare.
A brief review of common dental disease and treatment is necessary. Caries involves bacterial invasion and destruction of tooth structure, and is treated by removal of infected tissue followed by ‘filling’ with dental restorations. In untreated caries, bacteria invade the vascular dental pulp with an eventual spread to bone at the root apex (Figure 1). The spread of infection to soft tissues may be followed by life-threatening sepsis. Restorations may be either direct into teeth, or alternatively ‘indirect restorations’ cemented into place after preparation using plaster models. Direct restorations may be of amalgam, mostly used in posterior teeth, or of adhesive tooth-coloured material. Although adhesive materials are aesthetically pleasing, amalgam has greater longevity.18,19 When tooth structure is severely compromised, it becomes necessary to ‘cut the tooth back’ to a thimble shape to accept indirectly prepared crowns enclosing the entire tooth surface (Figure 1). Inlays are smaller indirect restorations of gold or porcelain. Most restorations eventually require replacement accompanied by additional loss of tooth structure, so that a conservative approach is preferred. If caries infection has spread to the pulp or bone, the tooth must either be extracted, or an endodontic procedure performed to remove infected dental pulp and obturate the pulp chamber with a ‘root canal filling’ (Figure 1).
In periodontitis, irritant plaque destroys the periodontal ligament and bony tooth support with eventual tooth loss. Treatment includes improved oral hygiene, curettage, and surgical tissue remodelling.
When only some teeth are lost, they may be replaced using either bridges or partial dentures. A bridge consists of a false tooth ‘pontic’ held in place by two crowns on either side of the offending gap. While bridges are permanently cemented into place, partial dentures are removable and fixed by clasps grasping natural teeth. Denture clasps may be part of a cast metal framework, or alternatively just wires embedded in a resin base. Partial dentures with a cast metal framework are generally preferred over those with an acrylic base because of greater comfort and longevity. While any ill-fitting partial denture may traumatise gingiva and act as a plaque and food trap, these problems seem less pronounced when cast metal frameworks rather than acrylic bases are used.
When all teeth are lost, replacement is with a full denture. Osseointegrated implants may be used to anchor full dentures, partial dentures and also crowns or bridges.20
General dental practitioners and specialists deliver the full range of dental services, while prosthetists with dental technician background and additional clinical training are able to make dentures and denture repairs.
There has been public discussion of possible over-servicing in the CDDS,21–23 while the federally appointed National Health and Hospital Commission recently recommended a separate universal dental health insurance program,24,25 and the Greens political party has announced a policy of expanding the CDDS to include the entire population.26,27 This study aims to describe patterns of service delivered under the CDDS over the first 23 months of implementation, both in light of and to inform public discussion.