Gingivitis is a category of periodontal disease in which there is no loss of bone but inflammation and bleeding are present.

Each tooth is divided into four gingival units (mesial, distal, buccal, and lingual) and given a score from 0-3 based on the gingival index. The four scores are then averaged to give each tooth a single score.

The diagnosis of the periodontal disease gingivitis is done by a dentist. The diagnosis is based on clinical assessment data acquired during a comprehensive periodontal exam. Either a registered dental hygienist or a dentist may perform the comprehensive periodontal exam but the data interpretation and diagnosis are done by the dentist. The comprehensive periodontal exam consists of a visual exam, a series of radiographs, probing of the gingiva, determining the extent of current or past damage to the periodontium and a comprehensive review of the medical and dental histories.

Current research shows that activity levels of the following enzymes in saliva samples are associated with periodontal destruction: aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma glutamyl transferase (GGT), alkaline phosphatase (ALP), and acid phosphatase (ACP). Therefore, these enzyme biomarkers may be used to aid in the diagnosis and treatment of gingivitis and periodontitis.

A dental hygienist or dentist will check for the symptoms of gingivitis, and may also examine the amount of plaque in the oral cavity. A dental hygienist or dentist will also look for signs of periodontitis using X-rays or periodontal probing as well as other methods.

If gingivitis is not responsive to treatment, referral to a periodontist (a specialist in diseases of the gingiva and bone around teeth and dental implants) for further treatment may be necessary.

Daily oral hygiene measures to prevent periodontal disease include:

- Brushing properly on a regular basis (at least twice daily), with the patient attempting to direct the toothbrush bristles underneath the gumline, helps disrupt the bacterial-mycotic growth and formation of subgingival plaque.

- Flossing daily and using interdental brushes (if the space between teeth is large enough), as well as cleaning behind the last tooth, the third molar, in each quarter

- Using an antiseptic mouthwash: Chlorhexidine gluconate-based mouthwash in combination with careful oral hygiene may cure gingivitis, although they cannot reverse any attachment loss due to periodontitis.

- Using periodontal trays to maintain dentist-prescribed medications at the source of the disease: The use of trays allows the medication to stay in place long enough to penetrate the biofilms where the microorganism are found.

- Regular dental check-ups and professional teeth cleaning as required: Dental check-ups serve to monitor the person's oral hygiene methods and levels of attachment around teeth, identify any early signs of periodontitis, and monitor response to treatment.

- Microscopic evaluation of biofilm may serve as a guide to regaining commensal health flora.

Typically, dental hygienists (or dentists) use special instruments to clean (debride) teeth below the gumline and disrupt any plaque growing below the gumline. This is a standard treatment to prevent any further progress of established periodontitis. Studies show that after such a professional cleaning (periodontal debridement), microbial plaque tends to grow back to precleaning levels after about three to four months. Nonetheless, the continued stabilization of a patient's periodontal state depends largely, if not primarily, on the patient's oral hygiene at home, as well as on the go. Without daily oral hygiene, periodontal disease will not be overcome, especially if the patient has a history of extensive periodontal disease.

Periodontal disease and tooth loss are associated with an increased risk, in male patients, of cancer.

Contributing causes may be high alcohol consumption or a diet low in antioxidants.

There are two main methods of detecting dental plaque in the oral cavity: through the application of a disclosing gel or tablet, and/or visually through observation. Plaque detection is usually detected clinically by plaque disclosing agents. Disclosing agents contain dye which turns bright red to indicate plaque build-up.

It is important for an individual to be aware of what to look for when doing a self-assessment for dental plaque. It is important to be aware that everyone has dental plaque, however, the severity of the build-up and the consequences of not removing the plaque can vary.

An examination by the dentist or dental hygienist should be sufficient to rule out the issues such as malnutrition and puberty. Additional corresponding diagnosis tests to certain potential disease may be required. This includes oral glucose tolerance test for diabetes mellitus, blood studies, human gonadotrophin levels for pregnancy, and X-rays for teeth and jaw bones.

In order to determine the periodontal health of a patient, the dentist or dental hygienist records the sulcular depths of the gingiva and observes any bleeding on probing. This is often accomplished with the use of a periodontal probe. Alternatively, dental floss may also be used to assess the Gingival bleeding index. It is used as an initial evaluation on patient's periodontal health especially to measure gingivitis. The number of bleeding sites is used to calculate the gingival bleeding score.

Peer-reviewed dental literature thoroughly establishes that bleeding on probing is a poor positive predictor of periodontal disease, but conversely lack of bleeding is a very strong negative predictor. The clinical interpretation of this research is that while BOP presence may not indicate periodontal disease, continued absence of BOP is a strong predictor (approximately 98%) of continued periodontal health.

Gingivitis can be prevented through regular oral hygiene that includes daily brushing and flossing. Hydrogen peroxide, saline, alcohol or chlorhexidine mouth washes may also be employed. In a 2004 clinical study, the beneficial effect of hydrogen peroxide on gingivitis has been highlighted.

Rigorous plaque control programs along with periodontal scaling and curettage also have proved to be helpful, although according to the American Dental Association, periodontal scaling and root planing are considered as a treatment for periodontal disease, not as a preventive treatment for periodontal disease. In a 1997 review of effectiveness data, the U.S. Food and Drug Administration (FDA) found clear evidence showing that toothpaste containing triclosan was effective in preventing gingivitis.

Plaque disclosing products, also known as disclosants, make plaque clinically visible. Clean surfaces of the teeth do not absorb the disclosant, only rough surfaces. Plaque disclosing gels can be either completed at home or in the dental clinic. Before using these at home or in the dental clinic check with your general practitioners for any allergies to iodine, food colouring or any other ingredients that may be present in these products. These gels provide a visual aid in assessing plaque biofilm presence and can also show the maturity of the dental plaque.

Diagnosis is usually clinical. Smear for fusospirochaetal bacteria and leukocytes; blood picture occasionally. The important differentiation is with acute leukaemia or herpetic stomatitis.

The cornerstone of successful periodontal treatment starts with establishing excellent oral hygiene. This includes twice-daily brushing with daily flossing. Also, the use of an interdental brush is helpful if space between the teeth allows. For smaller spaces, products such as narrow picks with soft rubber bristles provide excellent manual cleaning. Persons with dexterity problems, such as arthritis, may find oral hygiene to be difficult and may require more frequent professional care and/or the use of a powered toothbrush. Persons with periodontitis must realize it is a chronic inflammatory disease and a lifelong regimen of excellent hygiene and professional maintenance care with a dentist/hygienist or periodontist is required to maintain affected teeth.

Prevention of pericoronitis can be achieved by removing impacted third molars before they erupt into the mouth, or through preemptive operculectomy. A treatment controversy exists about the necessity and timing of the removal of asymptomatic, disease-free impacted wisdom teeth which prevents pericoronitis. Proponents of early extraction cite the cumulative risk for extraction over time, the high probability that wisdom teeth will eventually decay or develop gum disease and costs of monitoring to retained wisdom teeth. Advocates for retaining wisdom teeth cite the risk and costs of unnecessary operations and the ability to monitor the disease through clinical exam and radiographs.

Treatment includes irrigation and debridement of necrotic areas (areas of dead and/or dying gum tissue), oral hygiene instruction and the uses of mouth rinses and pain medication. If there is systemic involvement, then oral antibiotics may be given, such as metronidazole. As these diseases are often associated with systemic medical issues, proper management of the systemic disorders is appropriate.

Any tooth that is identified, in either the history of pain or base clinical exam, as a source for toothache may undergo further testing for vitality of the dental pulp, infection, fractures, or periodontitis. These tests may include:

- Pulp sensitivity tests, usually carried out with a cotton wool sprayed with ethyl chloride to serve as a cold stimulus, or with an electric pulp tester. The air spray from a three-in-one syringe may also be used to demonstrate areas of dentin hypersensitivity. Heat tests can also be applied with hot Gutta-percha. A healthy tooth will feel the cold but the pain will be mild and disappear once the stimulus is removed. The accuracy of these tests has been reported as 86% for cold testing, 81% for electric pulp testing, and 71% for heat testing. Because of the lack of test sensitivity, a second symptom should be present or a positive test before making a diagnosis.

- Radiographs utilized to find dental caries and bone loss laterally or at the apex.

- Assessment of biting on individual teeth (which sometimes helps to localize the problem) or the separate cusps (may help to detect cracked cusp syndrome).

Less commonly used tests might include trans-illumination (to detect congestion of the maxillary sinus or to highlight a crack in a tooth), dyes (to help visualize a crack), a test cavity, selective anaesthesia and laser doppler flowmetry.

Systemic antibiotics such as amoxicillin or metronidazole are sometimes used in addition to debridement based treatments.

"Systemic antimicrobials in conjunction with scaling and root planing (SRP), can offer an additional benefit over SRP alone in the treatment of periodontitis, in terms of clinical attachment loss (CAL) and probing pocket depth (PPD) change, and reduced risk of additional CAL loss. However, differences in study methodology and lack of data precluded an adequate and complete pooling of data for a more comprehensive analyses. It was difficult to establish definitive conclusions, although patients with deep pockets, progressive or 'active' disease, or specific microbiological profile, can benefit more from this adjunctive therapy."

There is professional agreement among dentists that smoking cessation and good oral hygiene are key to effective treatment and positive outcomes for patients.

The typical initial treatment known to be effective is scaling and root planing (SRP) to mechanically debride the depths of the periodontal pocket and disrupt the biofilm present. This is done using a powered ultrasonic or sonic scaler and/or unpowered hand instruments.

"In patients with chronic periodontitis, subgingival debridement (in conjunction with supragingival plaque control) is an effective treatment in reducing probing pocket depth and improving the clinical attachment level. In fact it is more effective than supragingival plaque control alone".

Full mouth disinfection protocols are favoured by some clinicians. There is no evidence that full mouth disinfection or full mouth scaling protocols improve the outcome when compared to standard mechanical scaling and root planing.

Open flap debridement is used by some practitioners particularly in deeper pocket areas. The advantages of this approach is better visualization of the root surface to be cleaned. This must be weighed against the risks of surgery. Open flap surgery is more effective than non-surgical periodontal therapy in deep pocketing : "Both scaling and root planing alone and scaling and root planing combined with flap procedure are effective methods for the treatment of chronic periodontitis in terms of attachment level gain and reduction in gingival inflammation. In the treatment of deep pockets open flap debridement results in greater PPD reduction and clinical attachment gain."

Guided tissue regeneration (GTR) using PTFE membranes is favoured by some practitioners, despite its cost and complexity: "GTR has a greater effect on probing measures of periodontal treatment than open flap debridement, including improved attachment gain, reduced pocket depth, less increase in gingival recession and more gain in hard tissue probing at re-entry surgery. However there is marked variability between studies and the clinical relevance of these changes is unknown. As a result, it is difficult to draw general conclusions about the clinical benefit of GTR. Whilst there is evidence that GTR can demonstrate a significant improvement over conventional open flap surgery, the factors affecting outcomes are unclear from the literature and these might include study conduct issues such as bias. Therefore, patients and health professionals need to consider the predictability of the technique compared with other methods of treatment before making final decisions on use."

Enamel matrix derivative (EMD) is favoured by some practitioners despite its high cost: "One year after its application, EMD significantly improved probing attachment levels (1.1 mm) and probing pocket depth reduction (0.9 mm) when compared to a placebo or control, however, the high degree of heterogeneity observed among trials suggests that results have to be interpreted with great caution. In addition, a sensitivity analysis indicated that the overall treatment effect might be overestimated. The actual clinical advantages of using EMD are unknown. With the exception of significantly more postoperative complications in the GTR group, there was no evidence of clinically important differences between GTR and EMD. Bone substitutes may be associated with less gingival recession than EMD."

If there is persistent continuation of inflammation and bleeding, a prescription of antiplaque rinse would be useful.

The presence of dental plaque or infection beneath an inflamed operculum without other obvious causes of pain will often lead to a pericoronitis diagnosis; therefore, elimination of other pain and inflammation causes is essential. For pericoronal infection to occur, the affected tooth must be exposed to the oral cavity, which can be difficult to detect if the exposure is hidden beneath thick tissue or behind an adjacent tooth. Severe swelling and restricted mouth opening may limit examination of the area. Radiographs can be used to rule out other causes of pain and to properly assess the prognosis for further eruption of the affected tooth.

Sometimes a "migratory abscess" of the buccal sulcus occurs with pericoronal infection, where pus from the lower third molar region tracks forwards in the submucosal plane, between the body of the mandible and the attachment of the buccinator muscle to the mandible. In this scenario, pus may spontaneously discharge via an intra-oral sinus located over the mandibular second or first molar, or even the second premolar.

Similar causes of pain, some which can occur in conjunction with pericoronitis may include:

- Dental caries (tooth decay) of the wisdom tooth and of the distal surface of the second molar is common. Tooth decay may cause pulpitis (toothache) to occur in the same region, and this may cause pulp necrosis and the formation of a periapical abscess associated with either tooth.

- Food can also become stuck between the wisdom tooth and the tooth in front, termed food packing, and cause acute inflammation in a periodontal pocket when the bacteria become trapped. A periodontal abscess may even form by this mechanism.

- Pain associated with temporomandibular joint disorder and myofascial pain also often occurs in the same region as pericoronitis. They are easily missed diagnoses in the presence of mild and chronic pericoronitis, and the latter may not be contributing greatly to the individual's pain (see table).

It is rare for pericoronitis to occur in association with both lower third molars at the same time, despite the fact that many young people will have both lower wisdom teeth partially erupted. Therefore, bilateral pain from the lower third molar region is unlikely to be caused by pericoronitis and more likely to be muscular in origin.

Since most toothache is the result of plaque-related diseases, such as tooth decay and periodontal disease, the majority of cases could be prevented by avoidance of a cariogenic diet and maintenance of good oral hygiene. That is, reduction in the number times that refined sugars are consumed per day and brushing the teeth twice a day with fluoride toothpaste and flossing. Regular visits to a dentist also increases the likelihood that problems are detected early and averted before toothache occurs. Dental trauma could also be significantly reduced by routine use of mouthguards in contact sports.

Dry socket typically causes pain on the second to fourth day following a dental extraction. Other causes of post extraction pain usually occur immediately after the anesthesia/analgesia has worn off, (e.g., normal pain from surgical trauma or mandibular fracture) or has a more delayed onset (e.g., osteomyelitis, which typically causes pain several weeks following an extraction). Examination typically involves gentle irrigation with warm saline and probing of the socket to establish the diagnosis. Sometimes part of the root of the tooth or a piece of bone fractures off and is retained in the socket. This can be another cause of pain in a socket, and causes delayed healing. A dental radiograph (x-ray) may be indicated to demonstrate such a suspected fragment.

Recent advances have seen the introduction of platelet derived growth factor (PDGF) infused bone graft material. This material is usually combined with the cellular matrix to form a soft bone paste that is then covered by the allograft. The development of this type of bone and tissue cellular matrix (also known as ortho filler) results in greater osseointegration with the patient's healthy bone and soft tissue.

Healing from such procedures requires 2–4 weeks. After a few months the results can be evaluated and in some cases the new tissue needs to be reshaped in a very minor procedure to get an optimal result. In cases where recession is not accompanied by periodontal bone loss, complete or near complete coverage of the recession area is achievable.

Depending on the shape of the gum recession and the levels of bone around the teeth, areas of gum recession can be regenerated with new gum tissue using a variety of gum grafting "periodontal plastic surgery" procedures performed by a specialist in periodontics (a periodontist). These procedures are typically completed under local anesthesia with or without conscious sedation, as the patient prefers. This may involve repositioning of adjacent gum tissue to cover the recession (called a pedicle graft) or use of a free graft of gingival or connective tissue from the roof of the mouth (called a "free gingival graft" or a Subepithelial connective tissue graft). Alternatively, a material called acellular dermal matrix (processed donated human skin allograft) may be used instead of tissue from the patient's own palate.

A systematic review reported that there is some evidence that rinsing with chlorhexidine (0.12% or 0.2%) or placing chlorhexidine gel (0.2%) in the sockets of extracted teeth reduces the frequency of dry socket. Another systematic review concluded that there is evidence that prophylactic antibiotics reduce the risk of dry socket (and infection and pain) following third molar extractions of wisdom teeth, however their use is associated with an increase in mild and transient adverse effects. The authors questioned whether treating 12 patients with antibiotics to prevent one infection would do more harm overall than good, in view of the potential side effects and also of antibiotic resistance. Nevertheless, there is evidence that in individuals who are at clear risk may benefit from antibiotics. There is also evidence that antifibrinolytic agents applied to the socket after the extraction may reduce the risk of dry socket.

Some dentists and oral surgeons routinely debride the bony walls of the socket to encourage hemorrhage (bleeding) in the belief that this reduces the incidence of dry socket, but there is no evidence to support this practice. It has been suggested that dental extractions in females taking oral contraceptives be scheduled on days without estrogen supplementation (typically days 23–28 of the menstrual cycle). It has also been suggested that teeth to be extracted be scaled prior to the procedure.

Prevention of alveolar osteitis can be exacted by following post-operative instructions, including:

1. Taking any recommended medications

2. Avoiding intake of hot fluids for one to two days. Hot fluids raise the local blood flow and thus interfere with organization of the clot. Therefore, cold fluids and foods are encouraged, which facilitate clot formation and prevent its disintegration.

3. Avoiding smoking. It reduces the blood supply, leading to tissue ischemia, reduced tissue perfusion and eventually higher incidence of painful socket.

4. Avoiding drinking through a straw or spitting forcefully as this creates a negative pressure within the oral cavity leading to an increased chance of blood clot instability.

The Kennedy classification quantifies partial edentulism. An outline is covered at the removable partial denture article.

Angular chielitis is normally a diagnosis made clinically. If the sore is unilateral, rather than bilateral, this suggests a local factor ("e.g.", trauma) or a split syphilitic papule. Angular cheilitis caused by mandibular overclosure, drooling, and other irritants is usually bilateral.

The lesions are normally swabbed to detect if Candida or pathogenic bacterial species may be present. Persons with angular cheilitis who wear dentures often also will have their denture swabbed in addition. A complete blood count (full blood count) may be indicated, including assessment of the levels of iron, ferritin, vitamin B12 (and possibly other B vitamins), and folate.

Dental plaque accumulates at the surfaces when proper cleaning and maintaining is not done. There is inflammation due to the bacteria released from the toxins. calculus forms and if not removed, causes this disease.

Angular cheilitis could be considered to be a type of cheilitis or stomatitis. Where Candida species are involved, angular cheilitis is classed as a type of oral candidiasis, specifically a primary (group I) Candida-associated lesion. This form angular cheilitis which is caused by Candida is sometimes termed "Candida-associated angular cheilitis", or less commonly, "monilial perlèche". Angular cheilitis can also be classified as acute (sudden, short-lived appearance of the condition) or chronic (lasts a long time or keeps returning), or refractory (the condition persists despite attempts to treat it).

Oral and maxillofacial pathology, previously termed oral pathology, is a speciality involved with the diagnosis and study of the causes and effects of diseases affecting the oral and maxillofacial regions (i.e. the mouth, the jaws and the face). It can be considered a speciality of dentistry and pathology. Oral pathology is a closely allied speciality with oral and maxillofacial surgery and oral medicine.

The clinical evaluation and diagnosis of oral mucosal diseases are in the scope of oral & maxillofacial pathology specialists and oral medicine practitioners, both disciplines of dentistry.

When a microscopic evaluation is needed, a biopsy is taken, and microscopically observed by a pathologist. The American Dental Association uses the term oral and maxillofacial pathology, and describes it as "the specialty of dentistry and pathology which deals with the nature, identification, and management of diseases affecting the oral and maxillofacial regions. It is a science that investigates the causes, processes and effects of these diseases."

In some parts of the world, oral and maxillofacial pathologists take on responsibilities in forensic odontology.