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The Continuum of Dental Caries--Evidence for a Dynamic Disease Process


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The eventual outcome of dental caries is determined by the dynamic balance between pathological factors that lead to demineralization and protective factors that lead to remineralization. Pathological factors include acidogenic bacteria, inhibition of salivary function, and frequency of ingestion of fermentable carbohydrates. Protective factors include salivary flow, numerous salivary components, antibacterials (both natural and applied), fluoride from extrinsic sources, and selected dietary components. Intervention in the caries process can occur at any stage, either naturally or by the insertion of some procedure or treatment. Dental caries covers the continuum from the first atomic level of demineralization, through the initial enamel or root lesion, through dentinal involvement, to eventual cavitation. The dynamic balance between demineralization and remineralization determines the end result. The disease is reversible, if detected early enough. Since demineralization can be quantified at early stages, before frank cavitation, intervention methods can be tested by short-term clinical trials.
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he process of dental caries is now well-understood, although there are many details
yet to be determined. Studies over approximately the last 20 to 30 years have
clarified the mechanisms of demineralization and remineralization and also elucidated
a great deal of the complex microbiology of the process (Loesche, 1986; ten Cate and
Featherstone, 1991). However, clinical trials are still conducted with the endpoint
being frank cavitation as measured and examined by standard criteria (Radike, 1972).
This endpoint of the caries process comes after months or years of decay progression
and is itself a rather crude measure. A great deal of time and effort has been spent in
modeling dental caries, both in the laboratory and utilizing the human mouth as a
laboratory, as well as in a range of animal models (ten Cate and Featherstone, 1991;
Featherstone, 1995; ten Cate and Mundorff-Shrestha, 1995; Zero, 1995). The
definitive proof, of course, of any product designed to intervene or reverse caries is the
so-called "clinical trial". With the in-depth understanding that we now have of the
dental caries process, it is possible to design measures for the detection of dental caries
at a much earlier stage and to assess the efficacy of therapeutic procedures to prevent
progression or, even better, reverse the process. However, there has been debate about
whether early caries turns into eventual cavitation, whether the different types of
caries are comparable, and whether the various modeling methods are predictive
(Featherstone, 1995). The purpose of the present paper is to present a brief review of
the continuum of dental caries and the evidence for caries being a dynamic disease
The categories of dental caries that are mostly considered by clinicians and researchers
are smooth-surface caries, pit and fissure caries, enamel caries, dentinal caries,
secondary caries, early childhood caries, and root caries. Other subdivisions may also
be considered and described clinically or histologically. The basic mechanism of dental
caries, as described in the next section, is the same for all of these so-called "types of
caries". Mineral is lost through attack by acid generated by bacteria. This is
demineralization. If demineralization continues, a cavity eventually occurs in whatever
form and in whatever position on the teeth in the mouth. The natural body repair
mechanism for dental caries is remineralization related primarily to minerals from
saliva diffusing back into the porous subsurface region of the caries lesion
(Featherstone, 2000). The physical treatment methodologies for restorative dentistry are
obviously different, depending on the location, extent, and seriousness of the decay.
However, the basic mechanistic principles are the same for all of the above-mentioned
categories of dental caries.
Dental caries is a simple process in concept, but complicated in detail. In outline, the
caries mechanism can be described as follows (Featherstone, 2000):
(1) Acidogenic (acid-producing) oral plaque bacteria ferment carbohydrates that
are taken into the mouth, thereby producing organic acids, including lactic,
formic, acetic, and propionic.
(2) These acids diffuse into the enamel (Featherstone, 1983), dentin, or
cementum, partially dissolving the mineral crystals (composed of carbonated
hydroxyapatite (LeGeros, 1991) as they travel.
(3) Mineral (calcium and phosphate) diffuses out of the tooth, leading eventually
The eventual outcome of dental caries is determined by
the dynamic balance between pathological factors that
lead to demineralization and protective factors that lead
to remineralization. Pathological factors include
acidogenic bacteria, inhibition of salivary function, and
frequency of ingestion of fermentable carbohydrates.
Protective factors include salivary flow, numerous
salivary components, antibacterials (both natural and
applied), fluoride from extrinsic sources, and selected
dietary components. Intervention in the caries process
can occur at any stage, either naturally or by the
insertion of some procedure or treatment. Dental caries
covers the continuum from the first atomic level of
demineralization, through the initial enamel or root
lesion, through dentinal involvement, to eventual
cavitation. The dynamic balance between
demineralization and remineralization determines the
end result. The disease is reversible, if detected early
enough. Since demineralization can be quantified at
early stages, before frank cavitation, intervention
methods can be tested by short-term clinical trials.
KEY WORDS: dental caries, demineralization,
remineralization, acidogenic bacteria.
Presented at the International Consensus Workshop on
Caries Clinical Trials, Glasgow, Scotland, January 7-10,
The Continuum of Dental Caries—
Evidence for a Dynamic
Disease Process
J.D.B. Featherstone
Department of Preventive and Restorative Dental Sciences,
School of Dentistry, University of California at San
Francisco, 707 Parnassus Avenue, San Francisco, CA
94143, USA;
J Dent Res
83(Spec Iss C):C39-C42, 2004
C40 Featherstone
J Dent Res
83(Spec Iss C) 2004
to cavitation if the process continues.
(4) Demineralization can be reversed by calcium and phosphate,
together with fluoride, diffusing into the tooth and depositing a
new veneer on the crystal remnants in the non-cavitated lesion
(this is remineralization).
(5) The new mineral crystal surface is much more resistant to acid
as compared with the original carbonated hydroxyapatite
(6) The process of demineralization and remineralization generally
occurs numerous times daily, leading either to cavitation, to
repair and reversal, or to maintenance of the status quo.
In root caries, the same mechanism occurs as outlined above,
initially causing demineralization and exposure of the collagen fibrils
(Wefel et al., 1985). Once the collagen is exposed, it is open to
breakdown by bacterially derived enzymes, leading to rapid cavitation
and breakdown of the dentin in the tooth root (Clarkson et al., 1986;
Kawasaki and Featherstone, 1997).
The bacteria that produce the acids fall into the category of
acidogenic bacteria and are also aciduric, which means that they can
live preferentially under acid conditions (Loesche, 1986). In normal
dental plaque, these acidogenic bacteria occupy less than 1% of the
total flora. As caries becomes progressive and more aggressive, the
environment in the plaque becomes more frequently acidic, and these
aciduric bacteria survive at the expense of the other benign bacteria.
The most important aspect for the current discussion is that all acids
produced by the bacteria—including lactic, acetic, formic, and
propionic acids—can readily dissolve tooth mineral (Featherstone and
Rodgers, 1981). Two major groups of bacteria produce such acids,
namely, the mutans streptococci (including Streptococcus mutans and
Streptococcus sobrinus) and the lactobacilli species (Loesche, 1986;
Leverett et al., 1993). There are undoubtedly other acidogenic
organisms involved in dental caries. Until fairly recently, it was
considered that early childhood caries, a particularly rampant form of
caries manifested in young children, had a different etiology. However,
it is now obvious that the same bacteria are involved, but the reasons
for the rapid progression of the disease in these children are still
uncertain (Alaluusua et al., 1987; Caufield et al., 1993). Pit and fissure
caries now occupies much of the caries seen in Western countries,
since it appears that common therapeutic measures such as fluoride in
the drinking water and in fluoride products is not as effective in these
Wherever bacteria have niches in which to live, these
acidogenic/aciduric bacteria preferentially survive well. Therefore,
orthodontic subjects who have brackets or bands are at high risk of
caries, because the bacteria live well in the surrounding edges of these
appliances (O'Reilly and Featherstone, 1987). The same applies to
restorations with poor margins and pits and fissures.
Remineralization has been demonstrated in the laboratory for all types
of caries listed above, but of course, the deeper the caries lesion, the
harder it is for remineralization to be effective (ten Cate and
Featherstone, 1991). Whether a lesion will progress, stay the same, or
reverse is determined by the balance between protective factors and
pathological factors (Featherstone, 2000). This balance is illustrated in
Fig. 1. If the pathological factors predominate, then caries progresses.
If the protective factors predominate, then caries is halted or reversed.
In simple terms, the pathological factors are cariogenic bacteria,
salivary dysfunction, and frequency of ingestion of fermentable
carbohydrates. Once established in a particular person's mouth, these
cariogenic bacteria are very difficult to manage. Protective factors
include most of the components in saliva (such as calcium), phosphate,
fluoride, protective proteins that form the pellicle, proteins that
maintain supersaturation of the mineral in saliva and plaque, and
antibacterial substances naturally in saliva but also supplied
extrinsically (e.g., chlorhexidine), salivary fluoride, fluoride from
external sources, and substances (e.g., chewing gum) that stimulate
salivary function. Fig. 1 conceptually summarizes the dynamic process
of dental caries as being a balance, or imbalance, between
demineralization and remineralization that occurs numerous times
daily in the mouths of most humans.
Prevention, intervention, and reversal of dental caries can be enhanced
by either reducing the pathological factors or enhancing the protective
Antibacterial therapy such as treatment by chlorhexidine gluconate
mouthrinse has been shown to be effective in reducing the cariogenic
bacteria (Krasse, 1988). If the bacterial challenge is reduced, then the
protective factors have a greater chance of taking over and halting or
reversing dental caries (Featherstone, 2000). The natural antibacterial
substances in saliva, such as lactoferrin and the immunoglobulins, are
obviously not sufficiently active in cases where caries progresses.
Fermentable Carbohydrates
One of the most significant contributions to dental caries is the
frequency of ingestion of fermentable carbohydrates. Reducing the
frequency of ingestion is a behavioral matter. However, substituting
non-cariogenic sweeteners such as xylitol for the fermentable
carbohydrates such as glucose, sucrose, and fructose has been shown
to be effective in reducing the pathological challenge (Hildebrandt and
Sparks, 2000; Söderling et al., 2000).
In the case of reduced salivary function, there are fewer protective
factors provided by the saliva, and less ability for the saliva to enhance
remineralization, remove bacteria, or inhibit bacterial action.
Xerostomic patients have rampant caries if intervention strategies are
not put in place (Mandel, 1974, 1989). These subjects illustrate, in a
few months, the progression from smooth-surface caries to cavitation
and rapid breakdown of the teeth on all surfaces, related directly to the
lack of salivary function and the ability of the bacteria to take over and
produce mineral-destroying acids very rapidly (Dreizen et al., 1977).
It is very well-documented that, in clinical trials assessed by
conventional visual-tactile detection methods (Jenkins, 1985), fluoride
products such as toothpaste, mouthrinse, and office topicals have been
shown to reduce caries between 30 and 70% compared with no fluoride
therapy. Fluoride in the drinking water has also been shown, of course,
to be effective in reducing the severity of dental decay in entire
populations. However, it has become obvious that where the bacterial
Figure 1. Schematic diagram of the balance between pathological factors
and protective factors in the dental caries process. Reproduced with the
permission of the publisher, Munksgaard, from Featherstone (1999).
J Dent Res
83(Spec Iss C) 2004 The Continuum of Dental Caries C41
challenge is too high, it is not possible for fluoride to overcome this
challenge completely. Again, this is an illustration of the continuum of
dental caries and the ability or inability to balance the outcome
according to the schematic diagram in Fig. 1.
As described above, demineralization and remineralization occur in the
mouth several times daily as a dynamic process, with progression or
reversal of dental caries being the end result. The site at which the
caries occurs is determined by the acidogenic bacteria at that site and
access to either pathological factors and/or protective factors. Caries
begins to manifest itself at the atomic level as soon as a diffusing
molecule of organic acid reaches a susceptible site on a crystal surface
of carbonated hydroxyapatite down inside the tooth (Featherstone,
1983). This has been shown, by laboratory experiments, to cause
preferential loss of calcium, phosphate, and carbonate from specific
sites in the crystal. This process was visualized by Featherstone and
co-workers approximately 20 years ago (Featherstone et al., 1979,
1981). The reversal of demineralization also occurs at the atomic level
when calcium, phosphate, and fluoride come together to build a new
surface onto the existing crystal remnants that have remained
following demineralization. This again has been visualized at the
atomic level, at the ultrastructural level, and in chemical experiments
by numerous researchers (Featherstone et al., 1981; ten Cate and
Duijsters, 1983; ten Cate and Featherstone, 1991; ten Cate and
Mundorff-Shrestha, 1995).
The process of dental decay can be modeled in the laboratory in
chemical or microbiological systems to produce the early
manifestation of caries, namely, the white spot lesion, decay around
orthodontic brackets, secondary decay around restorations, decay on
smooth surfaces or on occlusal surfaces, root caries, and dentinal
caries. In general, in the mouth, the process takes much longer than in
the laboratory models. The advantage of the models is that much can
be learned about processes involved in a much shorter period of time
(Featherstone, 1995; ten Cate and Mundorff-Shrestha, 1995). The
thousands of experiments that have been conducted and reported in
the literature for both in vitro and in vivo experiments readily confirm
that the caries lesion is formed by a continuous process starting at the
atomic level on the crystal surface in the subsurface of the tooth, and
progressing deeper and deeper into the enamel, or, in the case of root
caries ,starting in the cementum and eventually ending up in the
The dynamic nature of the process has been modeled in numerous
laboratories by various pH cycling models (ten Cate and Duijsters,
1982; Featherstone et al., 1990). To review these studies is beyond the
scope of the space of the present article. Suffice it to summarize that
these models can produce a continuum of the dental decay process
with end results ranging from an almost imperceptible white spot to a
cavity. For example, a recent study (unpublished) in our laboratory
examined pH cycling (alternating demineralization/remineralization)
over a period of 3 wks with 6 hrs of demineralization daily in a pH 4.3
partially saturated calcium and phosphate demineralizing solution and
17 hours of remineralization during every 24 hours, according to
methods reported previously (Featherstone et al., 1990). In between
each of the de- and remineralization steps, the crowns were subjected
to treatment in dentifrice slurries made from a range of products
containing, respectively, 2800 ppm F, 1100 ppm F, 250 ppm F as NaF,
and a placebo product with no added fluoride. At the end of the
experimental time, the teeth were hemi-sectioned and assessed by
cross-sectional micro-hardness (Featherstone et al., 1990). The relative
mineral loss (volume % x m) as Z was linearly related to the
negative logarithm of the fluoride content of the products (p < 0.01).
The lesion profiles are shown in Fig. 2. The placebo product contained
less than 1 ppm F. In the case of the treatment by the placebo,
cavitation occurred in some parts of some lesions, the lesions were
deep (Z approximately 4000) for the period of treatment, and the
mineral content remaining in the outer portion of the lesion was on the
order of 30% volume mineral (Fig. 2). On the other hand, the group
treated with the 2800-ppm-F product produced lesions that were barely
visibly perceptible as white spots, with a low Z value (approximately
500). This model clearly illustrates the continuum from almost no
effect of the strong acid challenge when treated with the high-F
product, to major demineralization and cavitation with the placebo
dentifrice. These results parallel those of clinical trials involving
similar products.
Similarly, the caries process can be modeled in the mouth with in
situ studies, as demonstrated over the last 30 years by numerous
laboratories, as reviewed in a recent conference (Featherstone, 1995).
Several models have been used, and these have been reported in many
papers. Most of the models involve utilizing extracted teeth and
placing enamel and/or dentin samples in the mouth and observing
subsequent demineralization or remineralization. Again, these models
have produced product efficacy indications similar to those found in
laboratory in vitro pH cycling studies. A model that is one step closer
to what might be considered 'natural caries' is one that uses orthodontic
appliances. In this case, true caries occurs on the smooth surfaces
surrounding these orthodontic appliances. For example, O'Reilly and
Featherstone (1987) reported such a model and based the development
of a pH cycling model on the results that they found in the human
mouth. Øgaard and co-workers have used orthodontic models,
particularly banding, to show severe caries challenge and rapid
progression of lesions in the mouth in a high-challenge situation with
poor access for remineralization (Øgaard and Rølla, 1992). There is no
reason to believe that caries around orthodontic brackets is any
different from any other of the forms of caries described above.
Since it has been established that the caries process is a
continuum, albeit one that is interrupted numerous times daily, it is
therefore possible to intervene at any stage with a therapeutic product
or an intervention methodology. If detection methods are accurate and
objective enough, then the disease can be followed over time, the rate
of progress measured, or the rate of reversal measured (Stookey,
In summary, dental caries covers the continuum from the first
atomic level of demineralization, through the initial white spot (or its
equivalent in the tooth root), often through dentinal involvement, to
eventual cavitation. All of the steps can be modeled in the laboratory
or in the mouth. The dynamic balance between demineralization and
remineralization, as determined by pathological factors and protective
Figure 2. Plot of volume % mineral
depth from the surface for 4
groups in a pH cycling study. Each group was treated between
demineralization and remineralization by a dentifrice containing,
respectively, (a) no added fluoride, (b) 250 ppm F, (c) 1100 ppm F, and
(d) 2800 ppm F each as NaF. Error bars are standard deviations for the
data at each depth from the surface. Each group is statistically
significantly different from every other group (p < 0.05).
C42 Featherstone
J Dent Res
83(Spec Iss C) 2004
factors, determines the end result. The disease of dental caries is
reversible, if detected early enough. It may be necessary to use
antibacterial methods as well as methods that enhance remineralization
or inhibit demineralization. With the sophisticated knowledge we now
have of the dental caries mechanism and our ability to quantify
demineralization at early stages, rather than wait for frank cavitation,
intervention methods can be tested by short-term clinical trials.
The contributions of many people to the studies reviewed here are
acknowledged sincerely. The space restriction of this limited review
makes it impossible to refer to all the relevant studies. The support of
numerous grants from commercial sources and from the National
Institutes of Health is also acknowledged with thanks.
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... The factors determining the appearance of carious pathology are, first, bacterial factors and factors related to diet; in fact, the quantity and frequency of carbohydrates introduced with diet are directly proportional to the risk of developing a carious lesion; therefore, acidogenic (acid-producing) oral plaque bacteria, ferment carbohydrates that are introduced into the mouth, producing organic acids, including lactic, formic, acetic, and propionic [2]. In addition, salivary factors, specifically the quantity and quality of saliva produced, were involved in this process. ...
... In general, the mechanisms of formation and evolution of dental caries can be described as follows: the bacterial plaque present, in particular Streptococci of the Mutans group as well as Lactobacilli, were responsible for the carbohydrates fermentation process and, as a consequence, there is a production of organic acids such as lactic acid and/or formic acid [2]. ...
... The initial stages of enamel caries involve the formation of a white spot lesion [2,4]. ...
Full-text available
The noncarious cervical lesions (NCCLs) recognize an etiological framework of onset very different from the carious processes with etiology whose bacteria aggregated in a biofilm play a predominant role, leading in this way to the loss of the mineralized structure of the tooth. The pathological picture of the NCCLs, which manifests itself with a clinical picture of dental wear, differs from caries because it mainly recognizes a series of pathological processes, such as erosion, through the action of generally acidic chemical agents and abrasion, which is basically expressed through repeated mechanical trauma characteristic of tooth brushing. However, in the literature, there is no unanimous agreement in identifying only these two mechanisms, but there are some who propose a more marked role of anomalous occlusal loads, which would be unloaded on some teeth which, in addition to both erosive and abrasive mechanisms, would give rise to abfraction. Therefore, the aim of this review was to collect literature etio-pathological information and discuss the mechanisms underlying NCCLs.
... These acids can lower the pH to acidic levels, which can induce demineralization of the tooth (removal of minerals from the tooth's enamel, dentin, and cementum) [7][8][9]. Defensive elements such as salivary flow, buffer systems, fluoride use, and a non-cariogenic diet can prevent and reverse the demineralization process [7,10]. However, when bacterial acid The tooth cavitation process can be initiated either in the crown portion of the tooth or in the tooth's roots. ...
... As stated above, cariogenic bacterial species initiate carious cavitation by acid generation that lowers the pH to a level that demineralizes dentinal collagen [1,[6][7][8][9][10]. Nevertheless, bacteria exhibit enzymatic activity that may directly degrade dentinal collagen once it has been exposed to acid [29,30]. ...
... This activity could contribute to carious cavitation by removing material and exposing additional mineralized tissue, using digested collagen as a nutrient source, and by compromising the ability of restorative components to adhere to the infected dentin [29]. Huang et al. discovered that although S. mutans are widely known for their ability to dissolve tooth enamel and dentin through acid production [10,21,30], they also possess direct degradative activities towards dentinal collagen [30]. Their study showed that through the generation of intracellular and extracellular proteolytic activity, this bacterium can degrade both collagen type-1 and demineralized human dentinal collagen. ...
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Until recently, it was widely accepted that bacteria participate in caries pathogenesis mainly through carbohydrate fermentation and acid production, which promote the dissolution of tooth components. Neutrophils, on the other hand, were considered white blood cells with no role in caries pathogenesis. Nevertheless, current literature suggests that both bacteria and neutrophils, among other factors, possess direct degradative activity towards both dentinal collagen type-1 and/or methacrylate resin-based restoratives and adhesives, the most common dental restoratives. Neutrophils are abundant leukocytes in the gingival sulcus, where they can readily reach adjacent tooth roots or gingival and cervical restorations and execute their degradative activity. In this review, we present the latest literature evidence for bacterial, dentinal, salivary, and neutrophil degradative action that may induce primary caries, secondary caries, and restoration failure.
... The outcome variable for the investigation is a continuous variable known as "decayed, missing, and filled tooth surfaces measure" (dmfs). Dental caries was identified by cavitated lesions, characterized either from evident fractures in the enamel or noticeable, irreversible enamel loss (23,24). The clinical data was collected by two providers. ...
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This study describes social support of Hispanic parents and the correlation with dental caries in their children. A cross-sectional study design was utilized to assess the 157 parent-child triads recruited from the Children's Hospital Colorado Dental Clinic. The Basic Research Factors Questionnaire (BRFQ) survey was utilized to assess parents' oral health knowledge, attitudes, behavior, and other psychosocial measures with social support as the main predictor variable. Bivariate associations between the independent variables and dmfs were conducted. Independent variables with a bivariate association of p ≤ 0.2 for the outcome variable were included in the multivariable linear regression model. Dental caries in children was significantly associated with less overall parental social support ( β = −10.10, p = 0.03). Overall social support was divided into four sub-categories: errand help, money help, childcare help, and transportation help. Dental caries decreased by 7.70 units for every 1-unit increase in transportation help ( β = −7.70, p = 0.03). A significant association was observed between parental knowledge on dental utilization and dmfs ( β = −2.70, p = 0.04). In the multivariable linear regression model, caries was significantly associated with social support ( β = −11.18, p = 0.02) and knowledge on dental utilization ( β = −3.84, p = 0.01). The study concludes that a higher level of social support and knowledge on dental utilization for Hispanic parents is correlated with lower rates of dental caries in their children.
... 1 These biofilms are created when bacteria adhere to a surface and bind together, surrounded by Extracellular Polymeric Substances (EPS). 2 Several oral health issues, such as dental caries, gingivitis, and halitosis, are attributed to oral biofilms. 3,4 This process occurs when facultative bacteria like Streptococcus sanguinis, Streptococcus mutans, Streptococcus oralis, and Streptococcus mitis attach to tooth surfaces coated with the acquired pellicle. The initial colonization of these bacteria leads to their aggregation on the tooth surface. ...
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Bacteria have a tendency to form multicellular biofilms, which adhere to surfaces and contain extracellular polymeric substances (EPS). This tendency is accompanied by hydrophobic interactions, which are vital in the biofilm attachment process. Oral biofilms contribute to a range of oral health issues, including gingivitis, dental caries, and halitosis. Therefore, this research aimed to investigate the correlation between oral biofilm growth inhibition and hydrophobicity reduction in Streptococcus mutants, Streptococcus sanguinis, Lactobacillus acidophilus, and Actinomyces viscosus. Essential oil-derived compounds, namely eugenol, C-10 massoia lactone, thymol, cinnamaldehyde, and zerumbone, were applied in the experiment. A microdilution assay using crystal violet staining evaluated the oral microbes' biofilm growth. The adhesion of microbes to hexadecane was measured to assess hydrophobicity reduction, which was analyzed correlatively using PAST (Paleontological Statistics) software and the Principal Component Analysis (PCA) method. The results showed a positive correlation of the hydrophobicity reduction towards the biofilm formation inhibition for all tested microbes (graphical angle <45°). The Principal Component (PC) analysis, based on the eigene values, showed that PC1 and PC2 accounted for 54.149% and 25.652% of the total variation, respectively. These two components explained 79.801% of the total variation, indicating a significant level of variability. This finding supported the notion that a greater reduction in microbial hydrophobicity was associated with stronger inhibitory activity against planktonic growth. The hydrophobicity reduction assay may indicate a potential of bioactive compounds against biofilm growth inhibition of oral microbes.
... Despite governmental efforts to prevent dental decay, the most common cause of tooth loss globally, the issue persists (1) . Dental disease is usually caused by an ecological imbalance in the balance between dental plaque and oral microbial biofilms (2) . ...
A mínima intervenção (MI) na odontologia visa uma proposta de preservação e conservação máxima da estrutura dentaria Sadia, utilizando estratégias educativas, preventiva e tratamentos terapêuticos. A mesma oferece um tratamento atraumático e contribui com bem estar do paciente podendo ser utilizadas em diversas áreas e pode ser aplicado em vários procedimentos da odontologia. O objetivo dessa pesquisa foi para avaliar o conhecimento dos discentes e a aplicação da MI na clínica odontológica da faculdade de Ilhéus, foi uma pesquisa de caráter qualitativo e explorativo com os acadêmicos da CESUPI através de um link enviado pelo whats app. A pesquisa ocorreu no período de 01 de outubro a 28 de outubro de 2023 com alunos do 7°ao 10° semestres, através de formulários online na plataforma do google forms. O resultado obtido ajudará na difusão e adesão da filosofia da MI com evidencias cientificas, é esperasse que os futuros profissionais utilizam e tenham conhecimento dos benefícios que essa técnica pode oferecer para o cirurgião e principalmente para os pacientes. Conclui- se que os acadêmicos demonstram ter conhecimento da importância do conceito e do uso da Mínima Intervenção, mesmo que nem todos utilizam no seu dia a dia.
Este artigo tem como tema a relação entre o aleitamento materno e a cárie de primeira infância- CIP, oriundo de uma problemática: o leite materno pode ser a causa da cárie na primeira infância? Essa discussão tem sido objeto de estudo e debate na área da odontologia. A CPI refere-se a cáries em crianças com menos de 6 anos de idade. O aleitamento materno exclusivo nos primeiros seis meses de vida é altamente recomendado e não aumenta significativamente o risco de cárie de primeira infância. O leite materno oferece benefícios protetores contra a CPI devido à sua composição equilibrada, presença de anticorpos e estímulo à produção de saliva. A prática de amamentação em livre demanda e a higiene oral adequada são importantes para manter a saúde bucal do bebê durante o aleitamento materno. No entanto, é sempre aconselhável consultar um profissional de saúde, como um pediatra ou odontopediatra, para obter orientações personalizadas sobre a amamentação e a saúde bucal do seu bebê. A investigação tem como objetivo identificar componentes do leite materno, descrever sobre a cárie e discutir as possibilidades de prevenção da doença. A metodologia é fundamentada na pesquisa bibliográfica com embasamento na revisão da literatura do banco de dados do SCIELO, PUBMED, GOOGLE ACADEMICO. Os estudos descrevem que não há evidências cientificas que comprovem que o aleitamento materno é o fator predominante para a cárie de primeira infância, tendo em vista que a doença cárie é multifatorial e biofilme açúcar dependente.
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Purpose: Optical coherence tomography (OCT) is an imaging device that can create cross-sectional images of tooth structure. This study evaluated the diagnostic performance of dental OCT system for occlusal caries in a real clinical situation. Methods: Twenty-four occlusal locations on 20 teeth were selected from 12 patients (mean age: 39.6 years). Swept-source OCT (SS-OCT) images were taken from the occlusal surfaces to diagnose occlusal enamel caries using the international caries detection and assessment system (ICDAS) grading. Indices of sensitivity and specificity for the detection of superficial enamel demineralization (code 1), distinct enamel demineralization (code 2), and enamel caries (code 3) were calculated from the results of visual inspection and SS-OCT obtained by three dentists with less than 2 years clinical experience. Results: The sensitivity of visual inspection and SS-OCT for enamel demineralization (code 1) were 0.22 and 0.55; for enamel demineralization (code 2) were 0.50 and 0.61; and for enamel caries (code 3) were 0.22 and 0.44, respectively. The specificity of visual inspection and SS-OCT were 0.52 and 0.78, respectively. Conclusion: SS-OCT can provide excellent diagnostic performance for occlusal enamel caries in a real clinical situation.
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Calcium phosphate (CaPO 4 ) coating is one of various methods that is used to modify the topography and the chemistry of Ti dental implant surface to solve sever oral problems that result from diseases, accidents, or even caries due to its biocompatibility and ability to remineralization. In this work, anodized (Ti-bare) was coated by CaPO 4 prepared from amorphous calcium phosphate nanoparticles (ACP-NPs) and confirmed the structure by X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) techniques. Ti-bare was coated by prepared CaPO 4 through the casting process, and the morphology of Ti/CaPO 4 was characterized by scanning electron microscope (SEM) where the nano-flakes shape of CaPO 4 and measured to be 60 ~ 80 nm was confirmed. The stability of Ti-bare and coated Ti/CaPO 4 was studied in a simulated saliva solution using electrochemical impedance spectroscopy (EIS) and linear polarization techniques to deduce their corrosion resistance. Furthermore, three essential oils (EO), Cumin, Thyme, and Coriander, were used to stimulate their synergistic effect with the CaPO 4 coat to enhance the corrosion resistance of Ti implant in an oral environment. The fitting EIS parameters based on Rs[R ct C]W circuit proved that the charge transfer resistance (R ct ) of Ti/CaPO 4 increased by 264.4, 88.2, and 437.5% for Cumin, Thyme, and Coriander, respectively, at 2% concentration. Our new results confirmed that it is necessary to maintain the positive effect of the components of the oral environment and their ability to synergize with the material of the modified Ti surface to ensure the success of Ti implantation. Thus, the use of EO with coat Ti/CaPO 4 proved great corrosion resistance value, which will enhance the remineralization process of the teeth.
Dental caries is a dynamic disease induced by the unbalance between demineralization of dental hard tissues caused by biofilm and remineralization of them; however, although various effective remineralization methods have been well documented, it is a challenge to reestablish the balance by enhancing remineralization alone while ignoring the antibacterial therapy. Therefore, the integration of remineralizing and antibacterial technologies offers a promising strategy to halt natural caries progression in clinical practice. Here, the conception of interrupting dental caries (IDC) was proposed based on the development of dual-functional coating with remineralizing and antibacterial properties. In this study, bovine serum albumin (BSA) loaded octenidine (OCT) successfully to form a BSA-OCT composite. Subsequently, through fast amyloid-like aggregation, the phase-transited BSA-OCT (PTB-OCT) coating can be covered on teeth, resin composite, or sealant surfaces in 30 min by a simple smearing process. The PTB-OCT coating showed satisfactory effects in promoting the remineralization of demineralized enamel and dentin in vitro. Moreover, this coating also exerted significant acid-resistance stability and anti-biofilm properties. Equally importantly, this coating exhibited promising abilities in reducing the microleakage between the tooth and resin composite in vitro and preventing primary and secondary caries in vivo. In conclusion, this novel dual-functional PTB-OCT coating could reestablish the balance between demineralization and remineralization in the process of caries, thereby potentially preventing or arresting caries.
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For many years after the discovery of its caries preventive effect, fluoride was thought to be primarily active by lowering the solubility of the apatitic mineral phase of the dental hard tissues. Recent findings have shed new light on the mechanisms by which fluoride inhibits or delays dental caries. Fluoride present in the oral fluids alters the rate of the naturally occurring dissolution and reprecipitation processes at the tooth-oral fluid interface. Demineralization of enamel is inhibited by concentrations of fluoride in the sub-ppm range. Likewise, remineralization of incipient caries lesions (the earliest stage of enamel caries) is accelerated by trace amounts of fluoride. As these two processes comprise dental caries the physiological balance between hard tissue breakdown and repair is favorably shifted by fluoride. The driving force for both phenomena is thermodynamic, that is, fluorapatite or a fluoridated hydroxyapatite may form when fluoride is supplied at low concentrations. This article critically reviews the current information about tooth-fluoride interactions, both from laboratory and clinical studies.
Background and Overview. Dental caries is a bacterially based disease. When it progresses, acid produced by bacterial action on dietary fermentable carbohydrates diffuses into the tooth and dissolves the carbonated hydroxyapatite mineral-a process called demineralization. Pathological factors including acidogenic bacteria (mutans streptococci and lactobacilli), salivary dysfunction, and dietary carbohydrates are related to caries progression. Protective factors - which include salivary calcium, phosphate and proteins, salivary flow, fluoride in saliva, and antibacterial components or agents-can balance, prevent or reverse dental caries. Conclusions. Caries progression or reversal is determined by the balance between protective and pathological factors. Fluoride, the key agent in battling caries, works primarily via topical mechanisms: inhibition of demineralization, enhancement of remineralization and inhibition of bacterial enzymes. Clinical Implications. Fluoride in drinking water and in fluoride-containing products reduces caries via these topical mechanisms. Antibacterial therapy must be used to combat a high bacterial challenge. For practical caries management and prevention or reversal of dental caries, the sum of the preventive factors must outweigh the pathological factors.
Three caries preventative regimens: oral hygiene; oral hygiene and topical fluoride; and oral hygiene, typical fluoride, and sucrose restriction were evaluated in patients with cancer given xerostomia-producing radiotherapy. The oral hygiene-fluoride gel combination was remarkably effective in protecting these high risk patients from caries, regardless of the cariogenicity of the diet.
A comparative study of synthetic and natural apatite has been made by means of high-resolution transmission electron microscopy, with the aim of elucidating structural differences between the two materials. Natural dental apatite is distinguished by the presence of mineral-deficient zones, which are likely centers for artificial etchant attack. The nature of these zones has been examined by the technique of preferential heavy-metal staining. This technique, in conjunction with the standard interpretation of lattice-image contrast, leads to the conclusion that these are naturally occurring calcium-deficient zones and are not the result of either beam damage or mechanical defect.
This paper presents the orthodontic banding model for vital teeth and the orthodontic in situ model for slabs of enamel, root surface, dentin, or other mineralized tissues such as shark enamel. The model for vital teeth is an in vivo model, since a crevice for plaque accumulation is created behind orthodontic bands on the buccal enamel surfaces of teeth in situ. Visible white-spot lesions are usually seen after a four-week banding period in the absence of fluoride. The microbiological flora developed behind the bands shows a similarity to that of natural caries. Microradiographic data show that the initial lesion is a softening of the enamel surface. Later, a subsurface lesion develops. A modification of the model has been developed for the use of slabs of mineralized tissues. In this model, slabs are mounted on a removable appliance. The slabs are covered with orthodontic banding material for plaque accumulation. Lesion development in enamel in the two model systems is almost identical. The benefit of the in vivo model is that caries development can be studied on vital teeth in young individuals. The model is independent of the patient's cooperation. No special diet is required, e.g., no sucrose rinsing. In the in situ model, slabs could be examined after one study period and then replaced for another period.
The anti-caries activity of fluoride is contributed to in several ways. Two major aspects of fluoride action are (i) the inhibition of demineralization at the crystal surfaces within the tooth, and (ii) the enhancement of subsurface remineralization resulting in arrestment or reversal of caries lesions. Fluoride present in the aqueous phase at the apatite crystal surface may play a determining role in the inhibition of enamel or dentin demineralization. In one part of the present study, the initial dissolution rate of synthetic carbonated-apatite in acetate buffers was measured with fluoride present in the buffer in the 0-2.6 mmol/L (0-50 ppm) range. Inhibition of demineralization was shown to be a logarithmic function of the fluoride concentration in solution. In the second part of the present study, an in vitro pH-cycling model was used for determination of the effect on net de/remineralization of enamel by treatment solutions containing fluoride in the 0-26 mmol/L (0-500 ppm) range. The net mineral loss was shown to be negatively related to the logarithm of the fluoride concentration. These studies have demonstrated an exponential quantitative relationship between fluoride concentration and inhibition of apatite demineralization or enhancement of remineralization. The clinical implications are (i) that simply increasing fluoride concentration may not necessarily give increased cariostatic benefit, and (ii) that improving the means of delivery of relatively low fluoride concentrations for longer times should be more appropriate for enhancing clinical efficacy.