By Marcel Alves Avelino de Paiva, Dayane Franco Barros Mangueira Leite, Isabela Albuquerque Passos Farias, Antônio de Pádua Cavalcante Costa and also Fábio Correia Sampaio

Submitted: June 8 hours 2017Reviewed: September 28th 2017Published: December 20th 2017

DOI: 10.5772/

Dental caries is a multifactor an illness affecting a significant number of people throughout the world. However, in recent years the widespread access of fluoride and other precautionary measures have resulted in a decline in the prevalence of caries amongst children and young adults. Currently, the is welcomed that most carious dental lesions are limited to specific anatomical sites. The aim of this chapter is to evaluation the influence of dentist anatomy on dental caries advancement while taking right into account recent findings in cariology. Occlusal fissures in the first permanent molar are usually the an initial sites in the irreversible dentition to build caries. An increased risk of caries is additionally found in proximal contacting surfaces between two surrounding teeth. Moreover, a partly erupted tooth, which go not take part in mastication, is likewise at hazard for caries due to the fact that it may carry out a more favorable atmosphere for bacterial build-up than a fully erupted tooth. Bacter biofilm top top the this is frequently a high risk caries environment. Expertise anatomical dental functions is of good importance because that guiding oral health and wellness hygiene and preventive measures. Finally, the advance of dental obstacle plays vital role in dentist caries risk.

You are watching: What is the name of the area where adjacent teeth physically touch


bacterial biofilmdental anatomydental cariesdental morphologytooth surfaces

1. Introduction

Dental caries affect a far-ranging number of populaces throughout the human being as a multifactor condition that is by and huge regarded as the most typical chronic condition worldwide <1>. That is estimated that 90% the dental difficulties are due to caries. However, the ubiquity of dental caries is variable and may be attached to social aspects, education level, income, and also dietary habits.

The an illness known together dental caries is generally identified as a “localized destruction of vulnerable dental difficult tissues through acidic byproducts from bacterial fermentation of dietary carbohydrates” <1>. In this definition, two necessary etiological factors are presented: dietary carbohydrates and also bacterial fermentation both require clarification worrying their modus operandi, and also “localized destruction” of dental tough tissues is likewise a issue to be studied.

A remarkable study on diet and prevalence entailing dental caries is perform 60 years earlier by Gustafsson and also co-workers <2>. Except the current perspectives concerning ethical issues when conducting clinical trials, the Vipeholm study clearly showed that dental caries are strongly tied to the accessibility of polished sugar. This was specifically evident for sugar intake in between meals. The is essential to allude out the at the time, the scientific ar was skeptical worrying the preventive impacts of reductions of sugar intake top top the formation of caries <3>. The idea the caries is not just a sugar-driven disease, yet actually is a sugar-disease, has been strongly protected <4>. Suspect this hypothesis, specific researchers regard dietary sugars as the main cause for the advancement and facility of caries.

In enhancement to sugar, the development of caries is clearly dependent on dental plaque activity. Current advances concerning the process of dental degeneration have shown that so-called “dental plaque” is in fact a “dental biofilm” <5>. The dental biofilm principle supports the idea of an organized microbial community. Thus, a adjust in nomenclature is not simply toward a brand-new name, yet represents true theoretical modifications in number of aspects. Today, bacterial biofilm is related to as a type of microcosm the bacteria and fungi both living and also competing within a complex matrix. In stimulate to assistance this point of view, caries is no longer seen as related to a solitary bacterium species. For numerous years, Streptococcus mutansthe most relevant sugar-fermenting, acidogenic species was regarded as the main causative certified dealer of dental caries. However, recent investigations have presented that dental caries are concerned a far-reaching and diverse ecosystem and surprisingly, S. Mutansis just a small fraction of the bacterial community <5>. It is likewise important to take into consideration that in most situations, the microorganisms of the dental biofilm room not pathogenic. In fact, certain bacteria are necessary due to the fact that a “healthy” biofilm forms naturally ~ above teeth and also helps come avoid emigration by exogenous species. If polished sugar is available, bacterial mountain production increases resulting in an prompt pH drop. Demineralization takes location in one acidic environment. Frequent cariogenic challenges result in mineral loss and development of carious lesions. Bacterial mountain production and its after-effects for the delicate balance between de- and re-mineralization had usually been assumed to be ecological phenomena <5, 6>. However, as currently noted, it is the communal life itself as created by this multiple microorganisms that collectively promotes carious lesion development.

Though dental caries is common in numerous populations the the world, over there is one evident decrease in the ubiquity of caries in many countries. This was quickly observed in industrialized and also developing nations. The main reasons for this decline in caries is concerned two factors: (a) the widespread usage of fluoridated products, an especially through the effective arrival of fluoride in toothpastes and also (b) separation, personal, instance commitment to oral hygiene habits, in other words, an ext people maintain reasonably great levels of oral hygiene transparent their resides <7, 8>. However surprisingly, in plenty of countries where decreases in caries were observed, sugar intake stayed stable <9, 10>.

The prevalence of dental caries is typically measured through epidemiological indexes such together the DMFT.This index quantifies dentist caries based on the variety of carious or decayed (D), absent (M), or to fill (F), teeth (T). The DMFT index does not administer information regarding carious attack severity, nor does it administer useful information worrying the surfaces of teeth wherein carious lesions occur. Therefore, the epidemiological index DMFS (decayed, missing, and also filled by surface), and other creates of measurement have been proposed <11>.

This decline in caries has actually raised specific interesting obstacles for dental professionals. For numerous individuals that the exact same age, the progression of carious lesions is no longer as fast as previously recorded. Thus, merely recording caries together a cavitated lesion is no longer the examine or clinical assessment finish point. Further, there is currently confusion in the terminology used in plenty of studies handling caries (e.g., “caries diagnosis” versus “carious lesions detection”) <11, 12>.

Dental caries deserve to be score in assorted levels that severity varying from white spot lesions to full cavitation. Caries diagnosis have the right to be thought about a multiple step procedure, starting with identification of the candidate lesion (caries detection), followed by evaluate of lesion severity, and also finally, decision of lesion task <12>. These are the main components guiding the facility of an ideal treatment plan (operative or non-operative) for modern primary or second caries management. Caries danger assessment, diagnosis, and synthesis (combining and also interpreting findings) are thought about to be the chief domains in Cariology, and the communication of clinical decision-making <13>.

Currently, all research study in dental caries prevention, development or treatment have to on one hand, consider the affect of fluoride ~ above the general decrease in caries, and also on the other hand advice the most relevant etiological factors. A third point concerning staying clear of dental caries must additionally be considered: a great understanding of dentist anatomy. Complete recovery the tooth role can just be achieved if a great knowledge of dental anatomy is applied. In addition, the science of dentist anatomy is also important for expertise carious risk to a certain tooth, or to particular areas in ~ the mouth <14>.

Dental caries is a disease mediated by biofilm and also pH that affects people from everywhere the world. Street intake patterns are likewise important and also may explain why some human being have an ext caries 보다 others. Caries may also impact socially vulnerable individuals an ext than those who have the right to afford to maintain oral restroom habits. As caries disproportionally affect certain groups of individuals, the exact same is true for details groups that teeth. Why do caries affect molars more than incisors? Why room caries much more prevalent in occlusal surfaces as contrasted to free and smooth surfaces? This is whereby dental anatomy and also caries meet. The aim of this thing is to review details features of dentist anatomy and also their affect on the development of dentist caries.


2. Ethics of cariology: dentist caries reviewed

Cariology is normally known together the examine of dentist caries or tooth decay. Yet for plenty of dental students, cariology is no a true clinical science, because it is (at least in many cases) presented just at the beginning of the undergraduate course, or merely as a research study project. However, recent developments provide brand-new perspectives come this field. Cariology is no confined to dental caries alone. Cariology includes research in dental tough tissues, dentist wear (erosive/non-erosive), and also dental tough tissue disorders <13>. This broader view of cariology opens new perspectives in dental education and also research, being a strong motive for enhancing diagnostic skills, when treating and also preventing carious lesions in more effective means <15, 16>.

2.1. Dentist caries

Dental caries is ubiquitous worldwide. That is a sugar-driven, biofilm-dependent, multifactor disease, and also in many aspects a dynamic process. The continuous presence that pathogenic dental biofilms is the key etiological aspect for demineralization and as declared before, certain reports give focus to diet sugars as the main reason for dental caries <4, 17, 18, 19>. However, other etiological components cannot it is in neglected <20>. Because that instance, the presence of street alone top top a free biofilm dental surface ar will not an outcome in dental caries. Dental caries outcomes from a transition inlocal setting acidity advocated by microbial management on a tooth surface. Mineral ns on a tooth surface ar is so subtle in the start that even very sensitive techniques are unable to show when a carious dentist lesion has started. Constant mineral casualty eventually come to be a pit or a small cavitation <21>.

The significant factors associated in the dental caries mechanism are well understood. Presently, that is embraced that dental biofilms pat a main role in dentist caries. Dental caries appear on the tooth only where dentist biofilms are found. That is also true that demineralization is furious by pathogen produced acids, and also the degree of mineral ns is directly modulated by both the visibility and task of these dental biofilms. Demineralization deserve to be interrupted or went back toward remineralization (a mineral restore process) as soon as the biofilm is one of two people partial or entirely removed <22>. This is a time-dependent facility process not a single event. Dental caries is always described as a chronic and progressive demineralization of difficult tissues that occurs in tooth surfaces underneath a microorganism layer.

The pathogenesis of dental caries is pushed by the facility of a dental biofilm and also formation of one acidogenic setting <20, 21, 22, 23, 24>. Constant de-mineralization events as result of repeated cycles that lactic acid production will eventually cause severe dissolved of the this enamel or dentin. As a result, white spots begin to appear underneath pathogenic biofilms. In many cases, the process takes several months, but it can occur in couple of weeks if the tooth surface ar is exposed to too much cariogenic challenges. Interestingly, simply as the microbial composition of dental biofilms can transition as pushed by diet, or v biofilm removal (oral hygiene), the microbial ar can additionally vary indigenous site-to-site within the mouth, as in between individuals.

Clinical microbiology studies have demonstrated the Mutans streptococci, especially S. Mutans, are more prevalent in kids who have actually experienced dentist caries throughout childhood <21>. Yet no all children who develop caries are colonized with Mutans streptococci. The observations administer a clean indication that dental caries are a an outcome of a very facility process influenced by the interplay of countless variables such as oral microbiota, saliva, dietary patterns, and oral hygiene behavior <25, 26>. The many recent agreement is that microbial diversity appears to be reduced in diseased than in healthy and balanced individuals and also may reflect the ecological pressure of lowered ecological pH <27>.

In enhancement to the distinctions in microbial patterns between healthy and disease individuals, a recent observation in kids showed that biofilms additionally differ follow to the site of the this <28>. In various other words, the eco-friendly pH within dental biofilms deserve to differ follow to its place on the tooth. This script supports observations that dental morphology contributes to pathogenic biofilm development at details tooth sites, and since outstanding enzymes reach free-surface biofilms much more easily 보다 those situated in dentist fissures; the connection becomes even much more complex. Yet, it have the right to be concluded the for dental caries there space predilection sites.

3. Dental morphology

Human dentist anatomy presents many instances of biologic variation, and for future dentist educational plan a greater variety of examples of dental morphology variation should be used. The usage of herbal teeth for to teach is very important, yet natural images deserve to also aid <29>. A straightforward investigation right into the exterior morphology that the person tooth clearly shows three unique parts:Crown: the top component of the tooth spanned in its exterior layer through enamel tissue. That is the only part you can typically see as soon as someone is smiling, despite a small part of it may be covered by the gums. The form of the tooth’s crown identify its function. The incisors and also canine this are very sharp and also chisel-shaped for cutting; premolars and molars have actually two or much more cusps because that grinding. The coronal component of the person tooth is composed of two tough tissues: enamel and dentin, this has the dentist pulp, situated in the crown.

Gumline: this is the component of the tooth in between the crown and also the root. It is whereby the gums satisfy the crown and the cementoenamel junction is located. This heat (also well-known as the cervical line) is easily visible to the nude eye due to the color difference between enamel and cementum.

Root: this is the component of the tooth the is embedded in the bone. The source of a tooth makes up around two-third that its totality structure. That is extended with cementum.

These three components of human being teeth play unique functions in ~ the dental cavity (Figure 1). Your anatomical features, size, and also shapes are directly related come their capacity to tear and crush the food. Incisor and also canine crowns have 4 surfaces and also a ridge (a straight elevation on the surface of a tooth), whereas premolar and molar crowns have five surfaces. The surfaces are called according to their positions and functions. Interestingly, teeth exposed to very strong masticatory pressures require better support area. This describes why molars have three roots, conversely, incisors have actually only one. In the dental environment, biting and chewing room very complicated phenomena i beg your pardon are also connected to the form, size, and also shape the the teeth <30, 31>.


Figure 1.

Dental tooth major anatomical parts. (A) Crown; (B) cervical line; (C) root.

Human teeth existing anatomical details concerned their specific duty during mastication, with depressions, elevations, concavities, and convexities. Native the view of anatomical features, the crown that a tooth have the right to be divide as having retentive and also non-retentive areas.

The line the separates these areas is dubbed the equatorial line. This is an imaginary heat that can be drawn by circling the many convex surfaces of a tooth: the lingual, buccal, and also proximal (Figure 2).


Figure 2.

The equatorial heat of a tooth. (A) Non-retentive area; (B) equatorial line; (C) retentive area.

Considering homologous teeth, the equatorial and also occlusal molar locations (surfaces close come equatorial lines) are on average bigger in males 보다 in females, though equatorial and also occlusal outlines the homologous left and also right molars in ~ both sex, and also arch (maxillary and mandibular) room similar, gift without size and also shape distinctions <32>.

The vestibular (buccal) and lingual edge heights (curvature crest) are important to divert and prevent food from getting stuck in the gingival sulcus. The stakes curvature is the anatomical allude on this crown whereby a parallel line attracted toward the middle-root axis heat touches the biggest convexity (protuberance). Contact areas between 2 teeth are recognized as proximal contour heights. The opportunity of food impactation at this points is a issue of concern. In healthy individuals or in many cases, point out of call between any tooth and any surrounding tooth readjust with time. In young persons, the call points of freshly erupted teeth room true contact points. In adults, after numerous years of small and regular movements, the tooth surfaces deserve to be flattered due to the fact that of mastication. It has been estimated that in an adult mouth that 40years that age, around 10mm of enamel have been worn off because of the contact area wear <30, 31>.

Certain major anatomical functions encountered when studying dentist morphology room presented in Table 1.

Anatomical featuresDefinition
CuspElevation or mound ~ above the crown that makes up a divisional part of the occlusal surface ofthetooth
TubercleSmaller elevation on some section of the crown developed by an extra formation of enamel
CingulumAlso well-known as “girdle” (Latim) is the lingual lobe of one anterior tooth. It makes up the mass of the cervical third of the lingual surface. That is convexity mesiodistally resembles a girdle encircling the lingual surface ar at the cervical third
RidgeLinear elevation on the surface ar of a tooth and is named according to its place (e.g., buccal ridge, incisal ridge, marginal ridge). Marginal ridges space those rounded borders of the enamel that kind the mesial and distal margins of the occlusal surfaces of premolars and molars and also the mesial and also distal margins of the lingual surfaces of the incisors and canines
SulcusLong depression or valley in the surface of a tooth in between ridges and cusps. A sulcus has actually a developmental groove in ~ the junction the its inclines
GrooveLinear channel or sulcus
FossaDepression ~ above the this surface
EmbrasuresOpen spaces in between teeth and also around a contact (e.g., occlusal (incisal) embrasures, buccal and lingual embrasures and gingival embrasures)

4. Dental anatomy and caries

Klein and Palmer were the an initial investigators to clearly describe relationships in between dental caries and also the assorted morphological tooth types <32, 33>. Your work detailed the an extremely useful details that mandibular molars were much an ext susceptible to carious attack than mandibular canines and also incisors. Although it seems obvious currently, this details was collected when many American cities had a high ubiquity of caries, and also the upper incisors were frequently affected by carious lesions. For the time, these relationship were rather obscure. Today, the seems obvious that occlusal surface irregularities have the right to facilitate biofilm advancement and eventually an outcome in carious lesions.

Depressions and grooves in the this are constantly anatomical clues of issue for dental caries (Figure 3). Because that the clinician, good individual sport is discovered in the occlusal areas of the teeth, however these occlusal areas and proximal contact points are normally the main emphasis of clinical examinations. The sulci of person teeth are generally V-shaped, and also though in most cases, the toothbrush bristles deserve to remove a good portion of biofilms in this area, details debris and also microbial biofilm will continue to be attached to the deeper components of the sulcus.


Figure 3.

Tooth depressions are always anatomical points for dental caries.

Certain researchers usage the term “groove-fossa system” (Figure 4A) once describing depressions in the occlusal component of a tooth the is vulnerable to dentist caries <34>. This is of details importance in Pedodontics for identifying risk locations for caries in deciduous this and an initial permanent molars. The pit formed by junction the developmental grooves is a an extremely interesting anatomical attribute in the molar occlusal surface; a very “tricky” area because that dental caries on the occlusal surface.


Figure 4.

(A) The “groove-fossa system” the a posterior tooth. (B) The accessory cusp in an top molar tooth.

Hidden caries is a term offered to define occlusal dentine caries that are missed upon intuitive examination <35>. In most hidden caries cases, a tiny open cavity is located in between grooves. Basically, the suggest occurs at the convergence the occlusal surface ridges that terminate at a main point in the bottom the the depression. The is a junction that grooves, also regarded together a little physiological-anatomical depression, and also easy come verify together an attractive ar for bacter growth. Together a result of constant deep demineralization, a cavity can show up below the resistant enamel. In general, its opening (aperture that the lesion) synchronizes to a small pit formed in the central fossa in between the triangle ridge and also the transverse ridge <35>.

The fifth cusp in the top molars (also known as the Carabelli trait) is frequently observed throughout dental examination. It has received countless different names together as: Carabelli trait, Carabelli tubercle, molar tubercle, enamel elevation, 5th cusp, accessory cusp, mesiopalatal prominence, and tuberculum anomalum <36>. That is much less prevalent in Asians, however is most typical in europeans 85% or White Caucasians. Carious lesions are likewise frequently observed at this site (Figure 4B).

A an extremely special landmark ~ above mandibular first molars is the mesiobuccal groove. It is a sort of sulcus that stretches from the occlusal surface ar to the buccal surface, and is frequently neglected throughout dental exams. Although periodically rather shallow, this narrow groove deserve to harbor a small but active bacterial ar which can easily provoke cavitation.

Microbial colonization is intended in locations where food impactation is frequent. Thus, every proximal locations below the contact suggest are favorable sites for food retention, biofilm advancement and caries. The reality is that together, every one of the teeth groups (incisors, canines, premolars and also molars) occupational harmonically toward breaking under food. After ~ a an excellent meal, it is evident that the anatomical functions of the teeth have worked together harmonically because that biting, crushing, and also chewing foodstuffs. However, the shapes of the teeth and their position in the dental cavity may reveal details gaps wherein food deserve to accumulate. Various other variables must additionally be thought about such as the wellness status that the gums and also the duration of tooth eruption.

Normal tooth eruption, breakthrough and dental occlusion fads reveal large variations. However, details common occasions are expected such together slow and irregular eruption of very first molars in youngsters and third molar eruption in adolescents and adults. The morphology that a tooth and its eruption time may lug a specific importance because that the advance of dental caries. Because of favorable problems for plaque build-up (biofilm formation), erupting teeth are an ext likely to construct dental caries. Further, there is also solid evidence the tooth anatomy may impact the likelihood of caries formation. Yet, exactly how deep is the connection between these variables?

A very interesting examine investigated the morphology of erupting third mandibular person molars including histological caries features and whether the morphology of interlobal grooves influences specific pathogen viability <37>. A total of 116 buccolingual sections of 22 this were examined, and the mesiodistal interlobal groove to be classified together either “fissure-like” or “groove-like”. “Fissures” were less prone come caries 보다 “grooves”. Viable microbe were seen at the entrance as well as in the interiors the the “grooves”. In “fissures” viable microorganisms were generally observed in ~ the entrance, when in the interiors microorganisms were much less viable or dead. The writer concluded the the inner morphology of interlobal grooves influences bacterial development conditions, and also determines locations for caries progression within a groove-fossa system.

The formation of a microbial biofilms on this is magnified by organic retention factors, i m sorry can likewise render remove by method of dental hygiene more difficult. Particular relevant retention determinants for biofilms top top the cervical 3rd and root include: supra- and subgingival calculi; cementoenamel junctions and enamel projections; furcation entrances and irregularities; cervical and root surface caries; and also tooth crowding in the arch. <38>.

Without suitable brushing and also flossing, microbial biofilms and also tartar can build up in ~ the gumline, resulting in gingivitis and also gum disease. If the margin that the gum tissue that surrounds the this wears away, the root surface ar is exposed and caries are most likely to develop. This is called gum recession, a facility process wherein the gums pulls back and the gum line changes. As soon as gum recession occurs, “pockets” or gaps kind between the teeth and the gum line. Under this influence, the teeth deserve to be severely damaged, and may ultimately result in this loss.

See more: Are Nonmetals Good Conductors Of Electricity ? Metals And Non

Human teeth existing a varied and complex morphology v bases in the innumerous anatomical characteristics listed for by your grooves, fissures, and also sulci. Particular teeth unexpectedly reveal risk areas in subtle and also hidden structures. For instance, the lingual pit in lateral top incisors must frequently be revitalized due come caries, because that in addition to its own morphology; the tooth has its surrounding tooth creating the embrasures and also contact points; an antagonist tooth the can pressure food and also debris toward the grooves, fissures, and sulci. Finally, the cervical third of the proximal surface is surrounded by the gums. This is a an extremely special area where open smooth surface may also present dentist caries, a spot wherein biofilms space not attached to any details anatomical feature. Microbial biofilms can type and build in plenty of anatomical tooth sites or also on complimentary smooth surface (cervical third) when problems are favorable. Table 2 presents the predilection sites for dental caries by tooth group.