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.

Pulp sensibility tests are routinely used in the diagnosis of dental disease. There are 2 general types:

- Thermal-- most commonly, ethyl chloride sprayed onto a small ball of cotton wool, which produces intense cold. Alternatively gutta percha can be heated to produce heat.

- Electrical pulp test-- electric pulp testing (EPT) has been available for over a century and used by dentists worldwide. It is used to determine the health of the pulp and pulp-related pain. It does not provide information on vascular supply to the pulp. EPT produces electrical stimuli that cause an ionic change across the neural membrane, inducing an action potential in myelinated nerves. The threshold of pain level will be determined by increasing the voltage. The requirements of an EPT are appropriate application method, careful interpretation of the results, and an appropriate stimulus. The tests must be done with tooth isolation and conduction media. EPT is not recommended for patients with orthodontic bands or crowned teeth. Key factors in testing are the enamel and dentine thickness and the number of nerve fibers underlying the pulp. Pulp nerve fibers respond to lower current intensities and a small number of pulpal afferents, creating neural responses when electrical stimulation is applied. EPTs may be unreliable and lead to false-positive and false-negative results. False-positive responses in teeth may be attributed to pulpal necrosis. Also, since pulpal and periodontal nerve thresholds may overlap, the periodontal nerves may give a false indication in tooth sensibility.

Possible explanations for false-positives include:

- Response caused by conduction of the current because of periodontal or gingival issues

- Breakdown products associated with pulp necrosis may be able to conduct electric current next to infected and hypersensitive pulp tissue

- Inflamed pulp tissue may still be present

- Metallic restorations or orthodontic gear are still present

Studies have indicated that there is little correlation between histopathological status of the pulp and clinical information. A negative EPT response showed localized necrosis in 25.7% of cases and 72% of cases. Thus, 97.7% of cases with a negative response to EPT indicated that a root canal treatment should be carried out.

The diagnosis of impaction can be made clinically if enough of the wisdom tooth is visible to determine its angulation, depth, and if the patient is old enough that further eruption or uprighting is unlikely. Wisdom teeth continue to move into adulthood (20–30 years old) due to eruption and then continue some later movement owing to periodontal disease.

If the tooth cannot be assessed with clinical exam alone, the diagnosis is made using either a panoramic radiograph or cone-beam CT. Where unerupted wisdom teeth still have eruption potential several predictors are used to determine the chance of the teeth becoming impacted. The ratio of space between the tooth crown length and the amount of space available, the angle of the teeth compared to the other teeth are the two most commonly used predictors, with the space ratio being the most accurate. Despite the capacity for movement into early adulthood, the likelihood that the tooth will become impacted can be predicted when the ratio of space available to the length of the crown of the tooth is under 1.

"Relative dentin abrasivity" ("RDA") is a standardised measurement of the abrasive effect that the components of the toothpaste have on a tooth.

The RDA scale was developed by the American Dental Association (ADA). The RDA scale compares toothpaste abrasivity to standard abrasive materials and measures the depth of cut at an average of 1 millimetre per 100,000 brush strokes onto dentine. This comparison generates abrasive values for the dentifrices that would be safe for daily use. In vitro dental studies showed a positive correlation between the highest RDAs and greater dentin wear.

Since 1998, the RDA value is set by the standards DIN EN ISO 11609. Currently, the claim on products such as toothpaste are not regulated by law, however a dentifrice is required to have a level lower than 250 to be considered safe and before being given the ADA seal of approval. The values obtained depend on the size, quantity and surface structure of abrasive used in toothpastes.

While the RDA score has been shown to have a statistically significant correlation to the presence of abrasion, it is not the only contributing factor to consider. Other factors such as the amount of pressure used whilst brushing, the type, thickness and dispersion of bristle in the toothbrush and the time spent brushing are other factors that contribute to dental abrasion.

The diagnosis of DH may be challenging. It is a diagnosis of exclusion, reached once all other possible explanations for the pain have been ruled out. A thorough patient history and clinical examination are required. The examination includes a pain provocation test by blasting air from a dental instrument onto the sensitive area, or gentle scratching with a dental probe. If a negative result for the pain provocation test occurs, no treatment for dentinal hypersensitivity is indicated and another diagnosis should be sought, such as other causes of orofacial pain.

Inflammation of the dental pulp, termed pulpitis, produces true hypersensitivity of the nerves in the dental pulp. Pulpitis is classified as "irreversible" when pulpal inflammation will irreversibly progress to pulpal necrosis due to compression of the venous microcirculation and tissue ischemia, and "reversible" when the pulp is still capable of returning to a healthy, non-inflamed state, although usually dental treatment is required for this. Irreversible pulpitis is readily distinguishable from DH. There is poorly localized, severe pain which is aggravated by thermal stimuli, and which continues after the stimulus is removed. There also is typically spontaneous pain without any stimulus. Reversible pulpitis may not be so readily distinguishable from DH, however usually there will be some obvious sign such as a carious cavity, crack, etc. which indicates pulpitis. In contrast to pulpitis, the pain of DH is short and sharp.

There is no standard to screen for wisdom teeth. It has been suggested, absent evidence to support routinely retaining or removing wisdom teeth, that evaluation with panoramic radiograph, starting between the ages of 16 and 25 be completed every 3 years. Once there is the possibility of the teeth developing disease, then a discussion about the operative risks versus long-term risk of retention with an oral and maxillofacial surgeon or other clinician trained to evaluate wisdom teeth is recommended. These recommendations are based on expert opinion level evidence. Screening at a younger age may be required if the second molars (the "12-year molars") fail to erupt as ectopic positioning of the wisdom teeth can prevent their eruption. Radiographs can be avoided if the majority of the tooth is visible in the mouth.

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.

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.

The presentation of caries is highly variable. However, the risk factors and stages of development are similar. Initially, it may appear as a small chalky area (smooth surface caries), which may eventually develop into a large cavitation. Sometimes caries may be directly visible. However other methods of detection such as X-rays are used for less visible areas of teeth and to judge the extent of destruction. Lasers for detecting caries allow detection without ionizing radiation and are now used for detection of interproximal decay (between the teeth). Disclosing solutions are also used during tooth restoration to minimize the chance of recurrence.

Primary diagnosis involves inspection of all visible tooth surfaces using a good light source, dental mirror and explorer. Dental radiographs (X-rays) may show dental caries before it is otherwise visible, in particular caries between the teeth. Large areas of dental caries are often apparent to the naked eye, but smaller lesions can be difficult to identify. Visual and tactile inspection along with radiographs are employed frequently among dentists, in particular to diagnose pit and fissure caries. Early, uncavitated caries is often diagnosed by blowing air across the suspect surface, which removes moisture and changes the optical properties of the unmineralized enamel.

Some dental researchers have cautioned against the use of dental explorers to find caries, in particular sharp ended explorers. In cases where a small area of tooth has begun demineralizing but has not yet cavitated, the pressure from the dental explorer could cause a cavity. Since the carious process is reversible before a cavity is present, it may be possible to arrest caries with fluoride and remineralize the tooth surface. When a cavity is present, a restoration will be needed to replace the lost tooth structure.

At times, pit and fissure caries may be difficult to detect. Bacteria can penetrate the enamel to reach dentin, but then the outer surface may remineralize, especially if fluoride is present. These caries, sometimes referred to as "hidden caries", will still be visible on X-ray radiographs, but visual examination of the tooth would show the enamel intact or minimally perforated.

The differential diagnosis for dental caries includes dental fluorosis and developmental defects of the tooth including hypomineralization of the tooth and hypoplasia of the tooth.

The early carious lesion is characterized by demineralization of the tooth surface, altering the tooth's optical properties. Technology utilizing laser speckle image (LSI) techniques may provide a diagnostic aid to detect early carious lesions.

MIH examination should be carried out on clean, wet teeth. The ideal age for examination is when the child is 8 years old - the age where all permanent first molars and most of the incisors are erupted. The permanent first molar will also still be in a comparatively sound condition without excessive post-eruption breakdown. Judgements of each individual teeth should be recorded, aiding the correct diagnosis of the condition.

There is currently a lack of standardisation in the scoring system and severity indices used to record the diagnosis of MIH. Various systems commonly employed in studies include:

- Modified Defect of Dental Enamel (DDE) Index: This set of criteria allows for enamel defects to be detected, enabling a distinction between demarcated and diffused opacities.

- European Academy of Paediatric Dentistry (EAPD) judgement criteria: This set of criteria was developed in 2003 to standardise classifications for use in epidemiological studies. However, while it allows the categorisation of the enamel condition, it does not address the severity of the enamel condition.

- Molar Hypomineralisation Severity Index (MHSI): This set of criteria has been developed to address deficiencies in indices concerning the severity of hypomineralisation. It is based on both the clinical characteristics of hypomineralised defects and the EAPD judgement criteria.

Personal hygiene care consists of proper brushing and flossing daily. The purpose of oral hygiene is to minimize any etiologic agents of disease in the mouth. The primary focus of brushing and flossing is to remove and prevent the formation of plaque or dental biofilm. Plaque consists mostly of bacteria. As the amount of bacterial plaque increases, the tooth is more vulnerable to dental caries when carbohydrates in the food are left on teeth after every meal or snack. A toothbrush can be used to remove plaque on accessible surfaces, but not between teeth or inside pits and fissures on chewing surfaces. When used correctly, dental floss removes plaque from areas that could otherwise develop proximal caries but only if the depth of sulcus has not been compromised. Other adjunct oral hygiene aids include interdental brushes, water picks, and mouthwashes.

However oral hygiene is probably more effective at preventing gum disease (periodontal disease) than tooth decay. Food is forced inside pits and fissures under chewing pressure, leading to carbohydrate-fueled acid demineralisation where the brush, fluoride toothpaste, and saliva have no access to remove trapped food, neutralise acid, or remineralise demineralised tooth like on other more accessible tooth surfaces. (Occlusal caries accounts for between 80 and 90% of caries in children (Weintraub, 2001).) Higher concentrations of fluoride (>1,000 ppm) in toothpaste also helps prevents tooth decay, with the effect increasing with concentration. Chewing fibre like celery after eating forces saliva inside trapped food to dilute any carbohydrate like sugar, neutralise acid and remineralise demineralised tooth. The teeth at highest risk for carious lesions are the permanent first and second molars due to length of time in oral cavity and presence of complex surface anatomy.

Professional hygiene care consists of regular dental examinations and professional prophylaxis (cleaning). Sometimes, complete plaque removal is difficult, and a dentist or dental hygienist may be needed. Along with oral hygiene, radiographs may be taken at dental visits to detect possible dental caries development in high-risk areas of the mouth (e.g. "bitewing" X-rays which visualize the crowns of the back teeth).

Dentin hypersensitivity may affect individuals' quality of life. Over time, the dentin-pulp complex may adapt to the decreased insulation by laying down tertiary dentin, thereby increasing the thickness between the pulp and the exposed dentin surface and lessening the symptoms of hypersensitivity. Similar process such as formation of a smear layer (e.g. from toothbrushing) and dentin sclerosis. These physiologic repair mechanisms are likely to occur with or without any form of treatment, but they take time.

Once the pulp has become inflamed, the tooth can be diagnostically divided into two categories.

- Reversible pulpitis

- Irreversible pulpitis

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.

It is recommended to parents and caregivers to take their children to a dental professional for examination as soon as the first few teeth start to erupt into the oral cavity

. The dental professional will assess all the present dentition for early carious demineralization and may provide recommendations to the parents or caregivers the best way to prevent ECC and what actions to take.

Studies suggest that children who have attended visits within the first few years of life (an early preventive dental visit) potentially experience less dental related issues and incur lower dental related costs throughout their lives.

Based on the optical changes induced in eroded tissue by the lesions, in 2015 Koshoji "et al." also demonstrated in a novel method that using laser speckle images (LSI) it is possible to acquire information on the microstructure of the enamel and detect minimal changes, such as early non-carious lesions. To produce the erosion, the samples were divided into four groups and immersed in 30 ml of a cola-based beverage (pH approximately 2.5) at room temperature. A representative image of the samples under white and laser illumination shows that although there are visible stains in the left portion of each sample due the dye from the cola beverage, structural changes are difficult to assess with the naked eye.

To differentiate the sound and eroded tissues, contrast analysis was performed of the speckle patterns in the images. Since this analysis is, in its essence, the ratio of the standard deviation and average intensity, the LASCA map of the lesion is generally higher than in sound tissue. This phenomenon is demonstrated in the LASCA maps which show the greater prevalence of dark blue on the right side, indicating sound tissue, and lower prevalence on the left side, indicating eroded tissue. The contrast ratio of the LASCA maps demonstrates that laser speckle images are sensitive to even small changes in the microstructure of the surface.

Erosion is highly prevalent in people of all ages. However, an objective diagnostic procedure is still needed, thus the study of the laser speckle imaging for tooth enamel may provide the first low cost objective diagnostic method for this disease. The analysis of laser speckle imaging in the spatial domain is a powerful diagnostic technique that provides information on the surface microstructure of tooth enamel after an acid etching procedure using patterns and LASCA maps. In an erosion model, these patterns are associated with mineral loss from the enamel. This method has proven sensitive to 10 minutes of acid etching on tooth enamel, which is a lesion so incipient that is not likely to be detected in clinical practice even by a trained dentist, besides it is also sensitive to the erosion progression.

The diagnosis of cracked tooth syndrome is notoriously difficult even for experienced clinicians. The features are highly variable and may mimic sinusitis, temporomandibular disorders, headaches, ear pain, or atypical facial pain/atypical odontalgia (persistent idiopathic facial pain).

When diagnosing cracked tooth syndrome, a dentist takes many factors into consideration. A bite-test is commonly performed to confirm the diagnosis, in which the patient bites down on either a Q-tip, cotton roll, or an instrument called a Tooth Slooth.

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.

In order for successful treatment of abrasion to occur, the aetiology first needs to be identified. The most accurate way of doing so is completing a thorough medical, dental, social and diet history. All aspects needs to be investigated as in many cases the cause of abrasion can be multi-factorial. Once a definitive diagnosis is completed the appropriate treatment can commence.

Treatment for abrasion can present in varying difficulties depending on the current degree or progress caused by the abrasion. Abrasion often presents in conjunction with other dental conditions such as attrition, decay and erosion however the below treatment is for abrasion alone. Successful treatment focuses on the prevention and progression on the condition and modifies the current habit/s instigating the condition.

On eruption of the first primary tooth in a child, tooth brushing and cleaning should be performed by an adult. This is important as the plaque that attaches to the surface of the tooth has bacteria that have the ability to cause caries (decay) on the tooth surface.

It is recommended to brush children’s teeth using a soft bristled, age and size appropriate toothbrush and age appropriate toothpaste twice daily, however children below the age of two usually don’t require toothpaste. These researches also suggest that it is suitable to brush children’s teeth until they reach the approximate age of 6; where they will begin to learn adequate dexterity and cognition needed for adequate brushing by themselves. It is encouraged to watch children brushing their teeth until they are competently able to brush appropriately alone.

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.

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.

Aetiology of CTS is multifactorial, the causative factors include:

- previous restorative procedures.

- occlusal factors

- developmental conditions/anatomical considerations.

- trauma

- others, e.g, aging dentition or presence of lingual tongue studs.

Most commonly involved teeth are mandibular molars followed by maxillary premolars, maxillary molars and maxillary premolars. in a recent audit, mandibular first molar thought to be most affected by CTS possibly due to the wedging effect of opposing pointy, protruding maxillary mesio-palatal cusp onto the mandibular molar central fissure.

Treatment for TRs is limited to tooth extraction because the lesion is progressive. Amputation of the tooth crown without root removal has also been advocated in cases demonstrated on a radiograph to be type 2 resorption without associated periodontal or endodontic disease because the roots are being replaced by bone. However, X-rays are recommended prior to this treatment to document root resorption and lack of the periodontal ligament.

Tooth restoration is not recommended because resorption of the tooth will continue underneath the restoration. Use of alendronate has been studied to prevent TRs and decrease progression of existing lesions.

Treatment options include antibiotic therapy (not a permanent solution), endodontic (root canal) therapy, or extraction.