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New classification of periodontal and peri-implant diseases

News introduced by the new classification of periodontal and peri-implant diseases.

classification of periodontal and peri-implant diseases
This article deals with the novelties introduced by the new classification of periodontal and peri-implant diseases. This new classification, which was created under the auspices of the American Association of Periodontology and the European Federation of Periodontology -the two world reference entities in periodontics-, was made with the ambition of providing all professionals with a standard and global language on periodontal and peri-implant conditions and pathologies; and, furthermore, it aims to remain among us for a long time, allowing the incorporation of future knowledge and evidence without the need to develop a new classification.

Periodontics has changed a lot in the last few years. Our knowledge about periodontal pathologies has evolved at a dizzying speed, and the irruption of peri-implant pathologies has forced us to focus on them. Therefore, it was necessary to incorporate this new knowledge into a new classification to facilitate its application to daily clinical practice. It has been complex and laborious work, but with the new classification, we have tried to achieve very ambitious challenges:

  • 1. A classification of all. The new classification was created under the supervision of the two world reference institutions in Periodontology, the American Association of Periodontology and the European Federation of Periodontology. Both organizations met in Chicago from November 9th to 11th to a significant representation of researchers and clinicians of world reference with the mission of proposing, developing, and approving a new classification. Although this meeting was only the high point of a work that began to be developed in 2015.

  • 2. Classification for all. It was born to provide all professionals with a standard and global language on periodontal and peri-implant conditions and pathologies. It is the ideal way to facilitate the diagnosis of the pathologies for all clinicians to determine the corresponding prognosis and treatment. At the same time, all researchers, when designing their studies, use the same definitions and variables. A common and global language will allow the comparison of different studies more simply, obtaining more significant knowledge about the prevalence, etiology, pathogenesis, natural history, and treatment of the other periodontal and peri-implant conditions and diseases.

  • 3. A classification to last. This new classification was born with the ambition of wanting to remain among us for a long time since it has been designed so that minor modifications can be made or subgroups added, allowing us to incorporate future knowledge and evidence without the need to develop a new classification.


The new classification tries to clarify many concepts and presents quite exciting novelties. Therefore, it is advisable to make a detailed review of the latest aspects.

The first significant novelty is that peri-implant conditions and diseases are incorporated into the classification. So the type is divided into two main groups: periodontal conditions, illnesses, peri-implant conditions, and disorders (See Table 1).

The review of the new classification by periodontal conditions and diseases is started. The first thing that stands out is that it includes only three general subgroups:

1. Periodontal health, gingival conditions, and diseases

2. Periodontitis.

3. Other conditions that affect the periodontium.

1. Periodontal health, gingival conditions, and diseases

The first subgroup describes gingival conditions and diseases, but an exciting novelty is that it first focuses on defining periodontal health and describing the variants that may exist. Of course, health has to be diagnosed, and the new classification wants to highlight this fact.

The importance of defining periodontal health lies in the fact that it is a necessary concept to be able to establish, for example, when an idea and an acceptable, successful result are achieved after the execution of periodontal treatment or to categorize the prevalence of gingival diseases in the population among many other utilities.

Based on the World Health Organization's (WHO) definition of health, periodontal health can be defined as a state free of inflammatory periodontal disease that allows the individual to have normal function and avoid the consequences (mental or physical) caused by having or having had the disease. Therefore, periodontal health is based on the absence of illness not only in patients who have not suffered from the disease but also includes patients who have had a history of successful treatment of gingivitis and periodontitis or other periodontal conditions and have been able to maintain their dentition without signs of clinical gingival inflammation.

In addition, it highlights that it has to be assessed both from a global point of view, i.e., considering the patient, and from an individual location. If a site is considered individually, the classification differentiates between pristine clinical health, which would be the ideal situation free of inflammation, and relatively infrequent gingival clinical health, which describes the most common problem and is the existence of a level of immune surveillance compatible with health. This means that at a histological level, we will find an inflammatory infiltrate composed mainly of neutrophils in the periodontal tissues, which is responsible for maintaining homeostasis with the biofilm. The fact that this inflammatory infiltration is compatible with health is highlighted.

This clinical health can be presented in three well-differentiated situations:

  • a. In an intact periodontium, that is, where there is no loss of insertion and bone.

  • b. In a Reduced Periodontium, that is to say, insertion and bone loss. Depending on the cause that has caused this loss, a distinction is made between

  • b.1 A patient with stable periodontitis. The loss of insertion and bone is because the patient has suffered periodontitis, has had successful treatment, and is durable.
  • b.2 Non-periodontal patient. Patients who present insertion and bone loss from other causes, such as patients with gingival recessions or patients who have undergone coronary lengthening surgery.

The clinical parameters that define clinical gingival health are the absence of bleeding on probing, erythema, edema, and symptoms on the part of the patient. The clinical parameter par excellence to differentiate gingival health and inflammation is bleeding on probing and must be evaluated as the proportion of locations that bleed when stimulated with a standardized probe and with a controlled force (0.25 N) in the apical part of the sulcus and in six areas, in all the teeth present in the mouth.
From an epidemiological point of view, a distinction is made between isolated inflamed sites and a case of gingivitis. Patients with gingival health present less than 10% of areas that bleed with probing depths of 3 mm or less. This is true for both intact and reduced periodontium. However, a distinction is made in patients with reduced periodontium due to periodontitis. In these patients, the concept of periodontal stability is introduced and defined, characterized by having carried out a treatment that has been successful through the control of systemic and local risk factors, achieving minimum percentages of bleeding on probing (less than 10%), that there is no probing depth of 4 mm or more excellent with bleeding, that it has optimally improved in other clinical parameters and that the progressive periodontal destruction has been stopped.

Similar to previous classifications, gingival diseases are divided into two large groups :

Gingivitis induced by dental biofilm.
Gingivitis not induced by dental biofilm
Dental biofilm-induced gingivitis is the inflammatory lesion resulting from the interaction between dental biofilm and the patient's immune-inflammatory response. It is contained within the gum and does not extend to periodontal insertion (cement, periodontal ligament, and alveolar bone). The inflammation does not extend beyond the mucogingival line and is reversible by reducing plaque levels at the gingival margin.

The range of plaque buildup needed to induce gingival inflammation and its impact on the extent, severity, and progression in specific locations and the entire mouth vary between individuals. This variation depends on local, predisposing, and systemic risk factors also called modifying characteristics. For this reason, three subtypes are created: plaque-induced gingivitis, plaque-only gingivitis, gingivitis mediated by local and systemic risk factors, and drug-associated gingival enlargement.

What is new in the classification is incorporating a much more detailed form of these local and systemic risk factors. The local or predisposing factors would be all those that favor plaque retention, either by facilitating the adherence and maturation of the biofilm or by increasing the difficulty of its removal by mechanical means, for example, the overflowing margins of restorations on teeth and oral dryness.
Systemic or modifying factors would be those characteristics present in a patient which negatively influence the immune-inflammatory response to dental biofilm, causing an exaggerated response or "hyper" inflammation. These factors are tobacco, metabolic factors such as hyperglycemia, nutritional factors such as vitamin C deficiency, pharmacological factors (prescribed, non-prescribed or recreational), hormonal factors, and different hematological conditions.

Like the concept of health, gingivitis can affect an intact or reduced periodontium in either a non-periodontal patient or a periodontal patient after successful treatment. The clinical parameter to make the diagnosis is bleeding on probing. Therefore, from an epidemiological point of view, a diagnosis of gingivitis in a patient with an intact or reduced non-periodontal periodontium is determined when there are 10% or more locations with bleeding on probing and a probing depth of less than or equal to 3 mm. When the percentage of bleeding is between 10-30% of locations, it is called localized gingivitis. It is called generalized gingivitis, with a rate greater than 30% of sites with bleeding on catheterization.

The importance is given to the fact that a case of periodontitis cannot be defined as a case of gingivitis, i.e., a patient with a history of periodontitis with gingival inflammation is still a case of periodontitis. Gingivitis is a significant risk factor and a necessary prerequisite for periodontitis. The management of gingivitis is the basis of the primary prevention of periodontitis.
Gingivitis not influenced by dental biofilm includes a variety of conditions that are not caused by biofilm and do not resolve after mechanical treatment. Such lesions may be manifestations of systemic diseases or be located in the oral cavity. Although these lesions are not caused by dental biofilm, the severity of the images usually depends on the accumulation of plaque and subsequent gingival inflammation