- Talon cusps.
- Pitted, grooved amelogenesis imperfecta (with sensitivity).
- Enamel pearls or root grooves.
Examples of iatrogenic factors include:
- Orthodontic appliances.
- Partial dentures.
- Ledges and overhangs on poorly fitting preformed metal crowns.
- Ledges and overhangs from intracoronal restorations.
11.9.2 General risk factors
General risk factors for periodontal disease may have a genetic basis, with certain
inherited conditions possessing periodontal manifestations (e.g. Papillon Lefevre
Syndrome). The genetic conditions are dealt with previously in this chapter. There are
also metabolic, haematological, and environmental risk factors within the general
category. A full discussion of each is outwith the scope of this chapter, so the two
most prevalent examples of general risk factors, diabetes mellitus and smoking will be
discussed.
Diabetes mellitus
Children with Type I diabetes with poor diabetic control are at risk of developing
periodontal disease. The link appears not to be directly with the level of plaque
control but to the presence of systemic complications, such as retinal and renal
problems. The overall severity of periodontal disease may increase with increasing
duration of the diabetes. There are a number of factors which may contribute to a
child's risk status. They may be inherited or secondary to high levels of blood glucose
(hyperglycaemia).
These can be outlined as:
- Defective polymorphonuclear leucocyte function (chemotaxis, phagocytosis, and
adherence); - Disordered collagen metabolism (gingival fibroblasts produce less collagen and the
polymorphonuclear leucocytes produce more of the enzyme collagenase than in non-
diabetics). This results in poor wound healing; - The hyperglycaemic state may favour certain inflammatory mediators and increase
oxygen radical production by macrophages.
Tobacco smoking
Smoking is now thought to be a significant environmental risk factor for periodontal
disease. Smokers have 3-6 times the level of periodontal disease when compared with
non-smokers and young people are thought to be more vulnerable. Often, the signs of
disease are masked because nicotine and other tobacco products cause
vasoconstriction, reducing the blood supply to the gingivae and lowering the tendency
to bleed.