Periodontal Bony Defects and Regenerative Therapies

Introduction:

Periodontal infections may not only lead to attachment loss, but if not treated, eventually tooth loss may occur. Though many patients know that this disease process can be interrupted or reversible when treated by regular dental follow-ups, oral prophylaxis, and chemical or mechanical plaque control, all of these can help arrest the progression of periodontal disease. In addition, patient awareness regarding the importance of oral health by seeking professional help can aid in preserving the dentition.

What Is the Pathophysiology of Bony Defects?

Before digging into the pathophysiology of bony defects, it is essential to know these terms:

• Intrabony - Inside the crest.

• Sprabony - Above the bone crest.

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When periodontal disease occurs, attachment loss can proceed in through intrabony defects. In this way, the base of the pocket is situated apical or below the bone wall. This is in opposition to the fact that a suprabony pocket develops with the base of the defect being coronal to the bone crest. Research shows that intrabony defects are more amenable to bone regeneration than suprabony defects. This is because when the amount of bone adjacent to the pocket increases, the bone available forms the matrix and aids further in new bone formation.

What Are Intrabony Defects?

The periodontal pocket can be surrounded by bone on one, two, or three sides. In terms of clinical attachment level gain as well as for reducing the probing pocket depth (PPD), surgical approaches or open flap debridement have proven beneficial in treating deep periodontal intrabony pockets (classified as PPD ≥ 6 mm). The walls of the intrabony defect can be located on the facial, lingual, or proximal sides of the exposed root surface. Also, the pocket itself can be visualized on the facial, lingual, or proximal surfaces. This can lead to combinations of these parameters occurring as intrabony defects. These defects remain relative to the tooth, wherein the number of osseous walls is considered dependent upon where the risk for periodontal microbial breakdown remains.

The interproximal areas may be involved most often as these are the least accessible areas that are difficult for daily removal of bacterial plaque.

What Are the Regenerative Therapies Used to Treat Periodontal Bony Defects?

Guided tissue regeneration and enamel matrix derivative are the primary modalities discussed below and are considered the gold standard treatment in regenerative periodontal therapy.

Guided Tissue Regeneration (GTR): Periodontal intrabony defects are usually predictably treated by periodontists and implantologists through guided tissue regeneration or GTR while planning dental implants. The dentist will primarily elevate the flap and remove the granulation tissue. Then a membrane is placed between the gingival surface and the cleaned root surface to cover the defect area completely. Finally, the repositioning of the flap is done that should be ideally sutured tension-free. The cells originating from the intact periodontal ligament are mainly allowed to form or condense the root surface resulting in regeneration of the periodontal structures (root cementum, periodontal ligament and alveolar bone) that are lost.

Enamel Matrix Derivatives (EMD): These are materials implicated by research or have been indicated to be effective in sites with more than 6 mm of periodontal probing depth (PPD) or sites associated with an observable radiographic vertical bone loss greater than 3 mm. According to dental research, histological data demonstrates that the use of EMD helps induce the formation of root cementum, periodontal ligament, and alveolar bone that are useful for periodontal health improvement over a while.

What Are Contained and Non-contained Defects?

The morphology of these defects is essential for the success of periodontal treatment.

• Self-contained intrabony defects are primarily narrowed by intact osseous walls, also called 3-wall defects. These are indicated for regenerative treatment by using a barrier membrane if needed.

• Unlike contained bony defects, the non-contained intrabony defects (1- or 2-wall defects) require soft tissue support. Therefore, for one walled to two walled defects, different kinds of bone grafts may be recommended by the periodontist with the use of a barrier membrane or EMD (enamel matrix derivative), respectively.

What Are the Risk Factors for Wound Healing?

The main factors that increase the risk for wound healing are discussed below:

• Systemic Conditions or Compromised Immunity - In patients with several systemic disorders and poor immune systems, the successful osseous regeneration is significantly impacted. For example, in insulin-dependent diabetes, the patient`s immune system is impaired, leading to failure in long-term regeneration therapy. In general, patients with a history of either diabetes or hypertension have poor wound healing. Tissue repair is also slow when immunity is impaired, as these risk factors reduce the prognosis for successful bone regeneration.

• Tobacco Usage - In the last few years, cigarette smoking has been implicated as having an adverse or detrimental effect on bone regeneration therapies. Therefore, patient history of smoking should be elicited by the dentist or the periodontist, and awareness among patients about smoking cessation post regenerative periodontal therapy is a must. This is essential for patient education that smoking is the leading risk factor for significantly lowering the prognosis of periodontal regenerative therapy.

Conclusion:

To conclude, the dental surgeon or the periodontist thus plays a pivotal role in assessing periodontal health for resolving either these intraosseous or extraosseous bony defects by providing various periodontal treatments. In addition, dentists are credible sources of therapeutic information, enabling patients to make good choices in time for proper oral health. A successful prognosis forms the basis of all periodontal therapies, which depend on the patient’s good oral hygiene before and after surgery. Good systemic health is also vital for success.