Periodontal Considerations in Restorative Dentistry

Aims of Periodontal Therapy

  • To arrest the disease process

  • Ideally, to regenerate lost tissues

  • To maintain periodontal health long-term

Result = Prevention of tooth loss

Periodontal Therapy as an Aid to Restorative Dentistry

  • Improves soft tissue management

  • Establishes stable gingival margin position

  • Contributes to aesthetics

  • Reduces tooth mobility

  • Compliance and response to treatment help establish prognosis

Inflamed Gingival Margin

  • Bleeds during operative procedures

  • Is unstable in its apico-coronal location

  • Gingival recession following non-surgical periodontal therapy

  • Gingival inflammation and papilla loss associated with a poorly fitting veneer and excess luting cement

    • Two weeks after the removal of veneer and debridement there has been further gingival recession

  • Periodontitis

    • Following non-surgical and surgical treatment there has been significant gingival recession

When planning restorations in the aesthetic zone, the position of the gingival margin is crucial.

The position of the gingival margin will be stable only if it is healthy.

Determinants of Gingival Margin Location

  • Presence or absence of inflammation

  • Biological width (2mm) – connective tissue of 1mm and junctional epithelium of 1mm (alveolar crest to gingival sulcus – supracrestial attachment)

The dimension of connective tissue to the gingival sulcus (3mm) cannot be reduced, it can be moved apically in its entirety.

Surgical Crown Lengthening is a Procedure in Which:

  • The biological width is relocated in an apical direction

  • To make the clinical crown longer

  • For instance, to improve aesthetics

Soft Tissue Harmony

  • Gingival display (1-4mm)

  • General gingival inclination (zenith from canines are parallel horizontal with interpapillary line and incisal plane)

  • Gingival outline and symmetry (upper gingiva in-line and lower gingiva below the line)

Increased gingival display = gingivectomy

Removing Gingival Tissue

  • Excision of soft tissue and bone

  • Move biological width apically

Restoration Margins

  • Should sit above the gingival margin

  • Anywhere within JE or connective tissue, will cause problems

Case: Through bone removal and manipulation of the mucoperiosteal flap the biological width has been relocated apically, allowing access to the crown margins and facilitating a return to tissue health

Crown Margins

  • Ensure the margins follow the shape of the tooth/gingiva to avoid going subgingivally in the approximal areas – DON’T CUT STRAIGHT ACROSS

  • Due to inflammation, we have lost some alveolar bone (to 3mm) so now we need the soft tissue to conform to that dimension by reducing the inflammation

    • The biological width can be accommodated between the crown margin and the bone

    • If the inflammation can be resolved, the crown margins will become accessible

“Well-fitting Provisional Restorations”

Problem – apical relocation of the gingival margin through the resolution of inflammation between the teeth can cause a ‘black triangle’

Healthy tissue + carefully located preparation margins = easy impression + reduced risk of disease

Overhanging Restorations

  • Jansson et al 1994 – periodontal pockets at proximal sites with marginal overhangs were significantly deeper compared to sites with metal restorations without overhangs

  • Prevented through the proper application of matrix bands

Keys to Periodontally Successful Restorations

  • Start with healthy tissue

  • Care with margin location and contour

  • Excellent provisional restorations

  • Facilitate plaque control

Patient with Missing Teeth

  • Is there a need to replace missing teeth?

  • With what should they be replaced with?

  • What are the problems in replacing missing teeth in patients with periodontitis?

Prognosis

  • How long do we expect these teeth to last?

  • Will more teeth be lost in the near future?

  • What will be the effect of any prosthesis on the prognosis for the teeth?

Support

  • Can we rely on the teeth for support for a restoration? (bridges/dentures, etc)

What are We Afraid of?

  • Abutments which are periodontally compromised will be “overloaded”
    Periodontitis will be made worse

    • Control the plaque

  • The teeth will be “loosened”

What’s Important?

  • Inflammation is controlled

  • Plaque control is not hindered

  • Forces on the teeth are controlled

Partial Dentures

  • Mucosa supported

  • Inflammation of the mucosa

  • Can be supported by teeth down the long axis with rest-seat preparations in crowns

RPDs

  • Effective tooth support

  • Clearance of gingival margins

  • Rigid connectors

Case:

  • Reduced but healthy periodontium

  • Extensive fixed bridge

    • Transmits forces down the long axis of the tooth

    • Cross-arch splinting

What about Implants?

  • Good implant survival in periodontitis patients can be achieved, but

  • Periodontitis patients are more likely to develop complications such as peri-implant mucositis and peri-implantitis

    • Warn patients of the risk

Conclusion

  • Effective treatment planning requires consideration of the role of the periodontal tissues

  • Healthy periodontal tissues make restorative dentistry easier and more predictable

  • Poorly designed restorations can adversely affect the health of the periodontium