Dentin or dentine is a calcified tissue of the body and, along with enamel, cementum, and pulp, is one of the four major components of teeth. It is usually covered by enamel on the crown and cementum on the root and surrounds the entire pulp. By volume, 45% of dentin consists of the mineral hydroxyapatite, 33% is organic material, and 22% is water. Yellow in appearance, it greatly affects the color of a tooth due to the translucency of enamel. Dentin, which is less mineralized and less brittle than enamel, is necessary for the support of enamel. Dentin rates approximately 3 on the Mohs scale of mineral hardness. There are two main characteristics which distinguish dentin from enamel: firstly, dentin forms throughout life; secondly, dentin is sensitive and can become hypersensitive to changes in temperature due to the sensory function of odontoblasts, especially when enamel recedes and dentin channels become exposed.
Tooth whitening or tooth bleaching is the process of lightening the color of human teeth. Whitening is often desirable when teeth become yellowed over time for a number of reasons, and can be achieved by changing the intrinsic or extrinsic color of the tooth enamel. The chemical degradation of the chromogens within or on the tooth is termed as bleaching.
The pulp is the connective tissue, nerves, blood vessels, and odontoblasts that comprise the innermost layer of a tooth. The pulp's activity and signalling processes regulate its behaviour.
Epidermal growth factor (EGF) is a protein that stimulates cell growth and differentiation by binding to its receptor, EGFR. Human EGF is 6-kDa and has 53 amino acid residues and three intramolecular disulfide bonds.
Abrasion is the non-carious, mechanical wear of tooth from interaction with objects other than tooth-tooth contact. It most commonly affects the premolars and canines, usually along the cervical margins. Based on clinical surveys, studies have shown that abrasion is the most common but not the sole aetiological factor for development of non-carious cervical lesions (NCCL) and is most frequently caused by incorrect toothbrushing technique.
The enamel organ, also known as the dental organ, is a cellular aggregation seen in a developing tooth and it lies above the dental papilla. The enamel organ which is differentiated from the primitive oral epithelium lining the stomodeum. The enamel organ is responsible for the formation of enamel, initiation of dentine formation, establishment of the shape of a tooth's crown, and establishment of the dentoenamel junction.
Pulpitis is inflammation of dental pulp tissue. The pulp contains the blood vessels, the nerves, and connective tissue inside a tooth and provides the tooth's blood and nutrients. Pulpitis is mainly caused by bacterial infection which itself is a secondary development of caries. It manifests itself in the form of a toothache.
Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people.
Dentin hypersensitivity is dental pain which is sharp in character and of short duration, arising from exposed dentin surfaces in response to stimuli, typically thermal, evaporative, tactile, osmotic, chemical or electrical; and which cannot be ascribed to any other dental disease.
An odontoma, also known as an odontome, is a benign tumour linked to tooth development. Specifically, it is a dental hamartoma, meaning that it is composed of normal dental tissue that has grown in an irregular way. It includes both odontogenic hard and soft tissues. As with normal tooth development, odontomas stop growing once mature which makes them benign.
In dentistry, the hydrodynamic or fluid movement theory is one of three main theories developed to explain dentine hypersensitivity, which is a sharp, transient pain arising from stimuli exposure. It states that different types of stimuli act on exposed dentine, causing increased fluid flow through the dentinal tubules. In response to this movement, mechanoreceptors on the pulp nerves trigger the acute, temporary pain of dentine hypersensitivity.
Pulpotomy is a minimally invasive procedure performed in children on a primary tooth with extensive caries but without evidence of root pathology. The minimally invasive endodontic techniques of vital pulp therapy (VPT) are based on improved understanding of the capacity of pulp (nerve) tissues to heal and regenerate plus the availability of advanced endodontic materials. During the caries removal, this results in a carious or mechanical pulp exposure (bleeding) from the cavity. During pulpotomy, the inflamed/diseased pulp tissue is removed from the coronal pulp chamber of the tooth leaving healthy pulp tissue which is dressed with a long-term clinically successful medicament that maintains the survival of the pulp and promotes repair. There are various types of medicament placed above the vital pulp such as Buckley's Solution of formocresol, ferric sulfate, calcium hydroxide or mineral trioxide aggregate (MTA). MTA is a more recent material used for pulpotomies with a high rate of success, better than formocresol or ferric sulfate. It is also recommended to be the preferred pulpotomy agent in the future. After the coronal pulp chamber is filled, the tooth is restored with a filling material that seals the tooth from microleakage, such as a stainless steel crown which is the most effective long-term restoration. However, if there is sufficient remaining supporting tooth structure, other filling materials such as amalgam or composite resin can provide a functional alternative when the primary tooth has a life span of two years or less. The medium- to long-term treatment outcomes of pulpotomy in symptomatic permanent teeth with caries, especially in young people, indicate that pulpotomy can be a potential alternative to root canal therapy (RCT).
Dental pulp stem cells (DPSCs) are stem cells present in the dental pulp, which is the soft living tissue within teeth. DPSCs can be collected from dental pulp by means of a non-invasive practice. It can be performed with an adult after simple extraction or to the young after surgical extraction of wisdom teeth. They are pluripotent, as they can form embryoid body-like structures (EBs) in vitro and teratoma-like structures that contained tissues derived from all three embryonic germ layers when injected in nude mice. DPSCs can differentiate in vitro into tissues that have similar characteristics to mesoderm, endoderm and ectoderm layers. They can differentiate into many cell types, such as odontoblasts, neural progenitors, osteoblasts, chondrocytes, and adipocytes. DPSCs were found to be able to differentiate into adipocytes and neural-like cells. These cells can be obtained from postnatal teeth, wisdom teeth, and deciduous teeth, providing researchers with a non-invasive method of extracting stem cells. The different cell populations, however, differ in certain aspects of their growth rate in culture, marker gene expression and cell differentiation, although the extent to which these differences can be attributed to tissue of origin, function or culture conditions remains unclear. As a result, DPSCs have been thought of as an extremely promising source of cells used in endogenous tissue engineering.
Pulp necrosis is a clinical diagnostic category indicating the death of cells and tissues in the pulp chamber of a tooth with or without bacterial invasion. It is often the end result of many cases of dental trauma, caries and irreversible pulpitis.
Dental pulpal testing is a clinical and diagnostic aid used in dentistry to help establish the health of the dental pulp within the pulp chamber and root canals of a tooth. Such investigations are important in aiding dentists in devising a treatment plan for the tooth being tested.
Dental trauma refers to trauma (injury) to the teeth and/or periodontium, and nearby soft tissues such as the lips, tongue, etc. The study of dental trauma is called dental traumatology.
Pulp stones are nodular, calcified masses appearing in either or both the coronal and root portion of the pulp organ in teeth. Pulp stones are not painful unless they impinge on nerves.
Regenerative endodontic procedures is defined as biologically based procedures designed to replace damaged structures such as dentin, root structures, and cells of the pulp-dentin complex. This new treatment modality aims to promote normal function of the pulp. It has become an alternative to heal apical periodontitis. Regenerative endodontics is the extension of root canal therapy. Conventional root canal therapy cleans and fills the pulp chamber with biologically inert material after destruction of the pulp due to dental caries, congenital deformity or trauma. Regenerative endodontics instead seeks to replace live tissue in the pulp chamber. The ultimate goal of regenerative endodontic procedures is to regenerate the tissues and the normal function of the dentin-pulp complex.
Pulp capping is a technique used in dental restorations to prevent the dental pulp from necrosis, after being exposed, or nearly exposed during a cavity preparation, from a traumatic injury, or by a deep cavity that reaches the center of the tooth causing the pulp to die. When dental caries is removed from a tooth, all or most of the infected and softened enamel and dentin are removed. This can lead to the pulp of the tooth either being exposed or nearly exposed which causes pulpitis (inflammation). Pulpitis, in turn, can become irreversible, leading to pain and pulp necrosis, and necessitating either root canal treatment or extraction. The ultimate goal of pulp capping or stepwise caries removal is to protect a healthy dental pulp and avoid the need for root canal therapy.
Atraumatic restorative treatment (ART) is a method for cleaning out tooth decay from teeth using only hand instruments and placing a filling. It does not use rotary dental instruments to prepare the tooth and can be performed in settings with no access to dental equipment. No drilling or local anaesthetic injections are required. ART is considered a conservative approach, not only because it removes the decayed tissue with hand instruments, avoiding removing more tissue necessary which preserves as much tooth structure as possible, but also because it avoids pulp irritation and minimises patient discomfort. ART can be used for small, medium and deep cavities caused by dental caries.
