Another sort of conditional, the counterfactual conditional, has a stronger connection with causality, yet even counterfactual statements are not all examples of causality. Consider the following two statements:

If A were a triangle, then A would have three sides. If switch S were thrown, then bulb B would light.In the first case, it would not be correct to say that As being a triangle caused it to have three sides, since the relationship between triangularity and three-sidedness is that of definition. The property of having three sides actually determines As state as a triangle. Nonetheless, even when interpreted counterfactually, the first statement is true. An early version of Aristotles "four cause" theory is described as recognizing "essential cause". In this version of the theory, that the closed polygon has three sides is said to be the "essential cause" of its being a triangle. This use of the word cause is of course now far obsolete. Nevertheless, it is within the scope of ordinary language to say that it is essential to a triangle that it has three sides. A full grasp of the concept of conditionals is important to understanding the literature on causality. In everyday language, loose conditional statements are often enough made, and need to be interpreted carefully. Questionable cause
Fallacies of questionable cause, also known as causal fallacies, non-causa pro causa (Latin for "non-cause for cause"), or false cause, are informal fallacies where a cause is incorrectly identified. Theories
Counterfactual theories
Counterfactual theories define causation in terms of a counterfactual relation.
Following this procedure, the gingival cuff tightens around the tooth, which may be enough to trap the bacteria left in the pocket. A gingival retraction cord which is accidentally left in situ is an occasional cause of a periodontal abscess. Penetrating injury to the gingiva--for example, with a toothbrush bristle, fishbone, toothpick or periodontal instrument--may inoculate bacteria into the tissues. Trauma to the tissues, such as serious impact on a tooth or excessive pressure exerted on teeth during orthodontic treatment, can be a possible cause as well. Occlusal overload may also be involved in the development of a periodontal abscess, but this is rare and usually occurs in combination with other factors. Bruxism is a common cause of excessive occlusal forces. Systemic immune factors such as diabetes can predispose a person to the formation of periodontal abscesses. Perforation of a root canal during endodontic therapy can also lead to a periodontal abscess which if left untreated could become "prolonged" ultimately rupture then enter the blood stream and could lead to serious situations such as endocarditis. Diagnosis
Periodontal abscesses may be difficult to distinguish from periapical abscesses. Since the management of a periodontal abscess is different from a periapical abscess, this differentiation is important to make (see Dental abscess#Diagnostic approach) For example, root canal therapy is unnecessary and has no impact on pain in a periodontal abscess. Classification
There are four types of abscesses that can involve the periodontal tissues:
Gingival abscess—a localized, purulent infection involves only the soft gum tissue near the marginal gingiva or the interdental papilla.