Risk factors for periodontal disease – The expression risk in this context means that, in the presence of a given factor, injury to or loss of periodontal tissue is a possibility. Risk factors may be local or systemic in nature.
Local contributing risk factors for periodontal disease fall into two general categories: Anatomic or iatrogenic. They share in common their ability to either facilitate bacterial plaque, and therefore calculus, accumulation/retention or their ability to interfere with plaque/calculus removal.
The local anatomic risk factors for periodontal disease include:
1. Furcation anatomy. In many instances, the entrance of bifurcations or trifurcations is restricted enough to limit access for mechanical root instrumentation. Once access to the intrafurcal space has been achieved, concavities in the furcal aspects of molar roots will limit instrumentation as well.
2. Intermediate bifurcation ridges extending from the mesial furcation surface of the distal root across the roof of the bifurcation to the distal surface of the mesial root of mandibular molars. These common anatomic deformities interfere with a patient’s ability to effectively remove plaque biofilm which are one of the risk factors for periodontal disease.
3. Cervical enamel projections (CEP). CEPs are tooth developmental deformities of the CEJ found on molars. These risk factors for periodontal disease are classified according to their involvement in tooth furcations. A Grade I CEP presents with minimal projection of enamel toward the entrance of the furaction. A Grade II CEP approximates the entrance of the furcation, and the tip of a Grade Ill CEP is well within the furcation.
4. Palato-gingival grooves (PGG). POGs are tooth developmental deformities of maxillary central and lateral incisors. They begin in lingual pits and extend vertically onto root surfaces. PGGs could, on rare occasions, extend to the root apex. PGGs are commonly associated risk factors for periodontal disease with increased gingival inflammation, plaque accumulation, and probing depth.
5. Open contacts and food impaction. Open contacts between teeth may be anatomical in origin, iatrogenic in origin, or be due to caries and pathologic migration of periodontally involved teeth. Food impaction is defined as the forceful wedging of food between teeth.
Any other accumulation of food or food debris around teeth should be categorized as food retention and is probably less threatening to the periodontium. Food impaction and subsequent retention may contribute to root caries in individuals who do not perform proper oral hygiene interdentally.
Open contacts by themselves probably do not contribute to periodontal pathology, but, in the presence of food impaction, open contacts have been associated with periodontal destruction. This may be particularly noticeable risk factors for periodontal disease where the progress of disease is in its early stages or particularly obvious where periodontitis is isolated to sites of open contacts/food impaction.
6. Other anatomic risk factors for periodontal disease are: The width of the space between teeth and root proximity (so-called kissing roots).
The latrogenic risk factors for periodontal disease are:
1. Overhanging dental restorations. Since dental restorations remain the mainstay of dental practice, it is not surprising that overhanging dental restorations are arguably the most common form of latrogeny to affect marginal periodontal health. Overhanging and improperly placed dental restorations are risk factors for periodontal disease and can be physically irritating, be plaque retentive, foster the growth of periodontal pathogens, alter the morphology of the interdental space, and violate the dentogingival junction (see 2 below). By virtue of their roughness and overall bulk, they may also interfere with interdental plaque control.
2. Violation of the “biologic width” is one of the risk factors for periodontal disease. After overhanging restorations, iatrogenic invasion of the biologic width may be the next more serious insult to the periodontium a dentist can make. The impact of this insult is usually permanent as the margins of dental restorations are inevitably placed in the wake of the insult. The biologic width is one of nature’s constant dimensional risk factors for periodontal disease.
It is most constant within individuals and less constant between individuals. If it is injured, it will repair. If however, restorative materials render the invasion of the biologic width permanent, periodontitis will produce apical migration of the junctional epithehum, resorption of crestal alveolar bone, loss of periodontal attachment, and possible vertical osseous defects. A new biologic width will repair a few mms apical to its original position on the tooth. This represents a net loss of attachment on the tooth. This is one of the risk factors for periodontal disease.
3. Open contacts and food impaction related to inadequate restorative dentistry. The impact of food impaction through open contacts created by iatrogeny offers the same threat to the periodontium as food impaction associated with open contacts that have resulted from growth and development or occlusal wear.
4. Occlusal traumatism associated with inadequate dentistry in 1, 2, and 3 above.
5. Additional local iatrogenic risk factors for periodontal disease include: Removable partial dentures and over dentures, fixed bridges, removal of third molar teeth in older adults, placement of fixed orthodontic appliances, and orthodontic movement of periodontally involved teeth.