The gastrointestinal system
C. Simon Herrington in Muir's Textbook of Pathology, 2020
The teeth consist of three specialized mineralized tissues with underlying soft-tissue pulp (Figure 10.1). Dentine is a thick layer of tubular, calcified, collagenous tissue that surrounds the pulp. On the crown of the tooth, the dentine is covered by enamel, an acellular tissue consisting largely of calcium apatite crystals in a delicate organic matrix. Cementum overlies the root dentine. At the apex of each root is one or more foramina through which vessels and nerves enter the pulp. The teeth are attached to the jaws by the periodontium, a specialized supportive complex comprising cementum, the periodontal ligament, alveolar bone, and gingiva. The deciduous or ‘baby’ teeth erupt within the first few years of life and total 20 in number. From 6 years of age, additional permanent teeth erupt and the deciduous teeth are gradually replaced by permanent successors to give a full adult complement of 32 teeth by the late teens.
Thermal stimulation of dentinal tubules
J. Belinha, R.M. Natal Jorge, J.C. Reis Campos, Mário A.P. Vaz, João Manuel, R.S. Tavares in Biodental Engineering V, 2019
The geometry of dentine presents micro tubules with variable dimensions and densities. According to Coutinho et al (2007), dentine can be subdivided into four different classes, depending on the number and shape of the tubules. Dentine presents a heterogeneous structure but the morphology is almost regular. This work considers the study of the region near the cusps (class II). Dentine can be directly exposed to high or low temperature, when the tooth is under restoration or due to gingival retraction. This temperature variation can induce pain into the patient. Thermal stimuli is normally used in clinical dentistry as a means of evaluating teeth vitality. Thermal stimuli using both heating and cooling are used as diagnostic to distinguish between a normal, inflamed or necrotic pulp. Some receptor neurons of the pulp are situated in the region of the pulpodentinal junction, being these receptors the first sensory structures to respond to external thermal stimulation.
The Role of Dentistry in Cardiovascular Health and General Well-Being
Stephen T. Sinatra, Mark C. Houston in Nutritional and Integrative Strategies in Cardiovascular Medicine, 2015
To appreciate why root-canaled teeth can be so dangerous, it is important to understand the process. A root canal is the removal of the pulpal tissue from the hollow tube within the root(s) of the tooth. This pulp is composed of nerves, blood, and lymphatic tissue. Dentists are taught to medicate the canal of the tooth during the root canal procedure to minimize the amount of bacteria left behind. The canal is usually packed with a latex material called gutta-percha, which supposedly seals off the canal. The underlying assumption is that the body will be able to tolerate a tooth that now contains a minimal amount of bacteria. The criteria for success are that a tooth does not hurt and that it appears normal on an x-ray. If it were just the pulp that was infected, a better outcome could be expected. However, the tooth’s dentin, the tooth material that surrounds the pulp, is composed of literally millions of tiny tubules. These tubules exist to transport nutrients to the entire tooth. Although we think of tooth enamel as a hard and impenetrable material, it is actually made up of thousands of microscopic tubules. In fact, the dentin comprises so many tubules that if the tubules in your small lower front tooth were laid out end to end, it is estimated that they would form a line approximately 3 miles long.
Reduced mesiodistal tooth dimension in individuals with osteogenesis imperfecta: a cross-sectional study
Published in Acta Odontologica Scandinavica, 2021
L. Staun Larsen, K. J. Thuesen, H. Gjørup, J. D. Hald, M. Væth, M. Dalstra, D. Haubek
In addition to OI, some individuals are diagnosed with dentinogenesis imperfecta (DI) as part of the same genetic disorder. A diagnosis of DI is established clinically by a characteristic greyish-blue to brown discolouration (opalescent) as well as pulp obliterations of the teeth [7,8]. The discolouration is due to the underlying affected dentine only, though, the enamel is fragile given this abnormality. Structurally, dentine is composed of hydroxyapatite crystals and an organic phase composed almost entirely of collagen type-1 and water. Depending on the impact of DI, the impaired collagen may affect the outer contours of the tooth and the dimension of the tooth crown. Furthermore, malocclusion in terms of mandibular overjet and open bite is a common trait in patients with OI [9–12]. In a recent study, individuals with OI were shown to have more severe malocclusions than a control group, including a potential increased risk of crowding of maxillary incisors [13]. Previous studies have demonstrated crowding in the dental arches to be positively correlated with mesiodistal dimension of teeth [14–17]. Thus, it might be hypothesised that the mesiodistal dimension of teeth is increased in patients with OI, compared to healthy individuals. This is in contradiction to the hypothesised reduced tooth dimension due to the impaired collagen. Potentially, deviations in dimension might have restorative implications.
Evaluation of patients’ perception of gingival recession, its impact on oral health-related quality of life, and acceptance of treatment plan
Published in Acta Odontologica Scandinavica, 2020
Merve Yılmaz, Bahar Füsun Oduncuoğlu, Mediha Nur Nişancı Yılmaz
Dentine exposure by gingival recession and/or loss of enamel is generally accepted as a predisposing factor for dentine hypersensitivity [30]. The answer of how could an appropriate stimulus applied to dentine surface evokes an instantaneous painful response has not been clearly stated [31]. In this study, the existence of hypersensitivity was evaluated by an air-blast test and recession sites were also examined with a dental explorer. Evaporative, thermal and tactile tests have been used clinically to replicate and confirm the patients’ sensitivity pain in response to chemical, thermal, tactile or osmotic stimuli [32]. Selecting the appropriate stimulus which can evoke a response is another issue to concern. Of these pain provocation tests, generally air-blast and/or tactile tests are used [33], although studies of these tests revealed less effective results when compared to one to another [34,35]. Thus, application of at least two different stimuli is recommended [36]. On the other hand, it should be kept in mind that assessment of dentine hypersensitivity always has a subjective basis and depends on the patients’ reaction to different stimuli which may be affected by patients’ pain perception, psychological and emotional factors [37]. The air-blast test and examination of recession sites with an explorer seemed to be effective to provoke a stimulus in this study however; application of another and/or additional test(s) and requesting the responses on a standard scale would have revealed the dentine hypersensitivity more clearly and would have decreased the subjectivity of the results.
Oral lesions associated with daily use of snus, a moist smokeless tobacco product. A cross-sectional study among Norwegian adolescents
Published in Acta Odontologica Scandinavica, 2023
Simen E. Kopperud, Vibeke Ansteinsson, Ibrahimu Mdala, Rune Becher, Håkon Valen
Several adverse health outcomes, such as cancer, adverse effects on pregnancy, and cardiovascular events have been associated with the use of snus [3]. Use of snus may also lead to local changes in the oral mucousa, so-called snus induced lesions, in the area where the snus is placed [4]. These changes are commonly seen as white and/or red changes with or without furrows, which can be graded according to their clinical appearance [5]. Reversibility of the lesions are reported when the individual stops using snus [6,7]. However, one study reported that not all lesions disappeared six months after quitting, specifically among users of nicotine replacement therapy [8]. Use of snus can also cause irreversible retraction of the gingiva and may lead to local periodontal changes (loss of supporting tissue) in the area where the snus is placed [9,10]. Thus, root cement and root dentin may be exposed, which may lead to tooth hyper sensibility. Although sparse data are available, previous studies have not shown any significant association between the use of snus and periodontal disease (general loss of dental supporting tissue) [11–13].