PD Ch5 Prevention and treatment of early caries in enamel
Background
billions ($) are spent all around the word to treat and for the prevention of dental caries at all socio-economic levels and ages (in particular in children)
Cariogenic processes start as soon as the tooth erupts into the oral cavity
first study which identified the dental caries as a oral/tooth disease was only published in 1870
populations such as Eskimos, and some small Indian populations seem to be “protected” against the dental caries probably due to particular foods
a taste of history and “curiosities.Dental caries affected human population since 14000 years ago
can be “easily” destroyed under particular biological or microbiological circumstances.
green tea
food rich in antioxidant
special water containing certain bacteriostatic
is a specific infectious microbiological disease
2 steps
subsequent destruction of the organic dental matrix (collagen fibrils).
localised demineralisation (ions dissolution) of the calcified dental hard tissues (enamel and dentine)
dynamic demineralization process of the dental hard tissue caused by the products of bacterial mratbolism(lactic and acetic acids乳酸和乙酸)occurs in alternate with periods of remineralization mainly due to the saliva
this process into the dentine causing the hydrolytic degradation水解降解 of the collagen fibrils induced by specific bacterial and endogenous內生的(MMP-metallo-protinases and cathepsins enzymes組織蛋白酶)
Current concept of caries etiology
a muti-factors equilibrium
usually stable in most people
A physiological equilibrium exists between remineralisation and demineralisation of the dental hard tissues in the oral cavity
remineralization
demineralization
Saliva
Remineraling agent
Antimicrobial agent
Effective diet
Bacteria
Salivary dysfunction
tooth defects
poor dietary habits
An increase in organic acids from dental plaque or acidic diet may lead to a change of this equilibrium inducing demineralisation of the tooth surface
Streptococcus dentisani--> kill other bacteria(protect)
Acquired Enamel Pellicle
forms on recently erupted teeth and on tooth surfaces exposed to saliva after being thoroughly cleaned with a toothbrush or undergoing professional prophylaxis.
is a protein film with unique composition and properties
formed by the selective adsorption of a variety of oral fluid–derived proteins onto tooth enamel surfaces.
Dental Biofilm
Enamel integrity is disrupted secondary to the formation of a dental biofilm
acquired enamel pellicle [a salivary protein pellicle] and dental plaque
caries process occurs along the interface between the dental biofilm and the enamel surface
The biofilm acts as a selective permeable membrane and restricts ingress of 限制了...的進入
antimicrobial agent
extracellular enzymes
noxious agents
Dental biofilms harbor cariogenic bacteria that are
acidogenic產酸 (produce organic acids)
aciduric酸性 (can survive in acidic environments)
Oral bacteria in the presence of fermentable carbohydrates produced acids that dissolved tooth structure
Although S. mutans is one of the most researched cariogenic microorganisms, it is only one of more than 500 species found in dental plaque.
Dental demineralization
Dentine demin
Root demin(or root caries.High root loss)
Enamel demin(or enamel caries)
pit and fissure
Smooth surface
Dental caries
Terminology術語
Attending to the activity
others
Attending to the location
primary, secondary, residual剩餘
proximal, gingival margin, pits and fissure
active lesion: progressing(quickly)
inactive: not progressing
Rampant or multiple caries placed in several and different location 橫行的或多個齲齒放置在多個不同的位置
baby bottle caries
hidden caries: X-ray detect
Steps
The first indication of tooth decay are white spots on the enamel caused by the loss of calcium and phosphates.
If the deminesalization process outruns超出 the natural remineralisation process, the lesion grows and a cavity is formed.
The bacteria may invade the pulp of the tooth,
causing a consistent tooth pain, especially during the night.
The bacteria may also produce an abscess,
and eventually the tooth may be extracted by the dentist
Dentine caries
Zone classification
Shape of the lesion is triangular with the apex toward the pulp and the base towards the enamel
Zone 1
zone 2
Zone 3(affectes)
Zone4(infected)
zone of fatty degeneration of tome's fibers,(next to pulp)due to degeneration of the odentoblast process
Zone of dentinal sclerosis
deposition of Ca salts in the tubules and makes the tubules impermeable
zone od decalcification of dentine
zone of decomposed dentine due to acids and enzymes and bacterial invasion
hypermineralized
pulp is reactive--. try to make stronger wall
demineralized enamel:histology
DZ:dark zone (caries-affected)
B:body of the lesion(caries-infected)
TZ: translucent zone (caries-affect)
SZ:surface zone(reaction front)
lies at the advancing front of the lesion, slightly more porous多孔 than sound(healthy) enamel;
this zone is usually present and referred to as positive zone formed due to demineralisation
found between the surface and the dark zone; it is the area of greatest demineralisation
sometimes greater resistance probably due to greater degree of mineralisation and F- concentration
it is not always present
Caries assessment
WHO had propagated its method, which was based on a ‘yes/no’ clearly cavitated dentine lesion, as a reliable data base was required for comparison of decayed, missing and filled (DMF) –NOT VERY USEFUL FOR PREVNTIVE AND MID
enamel carious lesions should be assessed as well, whether in clinical practice or when conducting an epidemiological survey
the International Caries Detection and Assessment System(ICDAS) Group in the spring of 2002.導致國際齲齒檢測和評估系統小組於2002年春季召開了第一次會議
ICDAS
Later, in 2005, this criterion of ICDAS was modified and ICDAS-II was created at the ICDAS workshop in Baltimore.
ICDAS II can distinguish accurately between lesions related to the outer or inner half of the enamel; this can be done fairly accurately in permanent teeth.
ICDAS II code and criteria
0
1
2
3
4
5
6
Sound tooth surface:Noe evidence of caries after 5 sec air drying
First visual change in enamel: Opacity or discoloration(white or brown) is visible at the entrance to the pit or fissure seen after prolonged air drying
Distinct visual change in enamel visible when wet, lesion must be visible when dry濕潤時可見牙釉質的明顯視覺變化，乾燥時必須可見病變
localized enamel breakdown(without clinical visual signs of dentinal involvement )seen when wet and after prolonged drying
Underlying dark shallow from dentine
distinct cavity with visible dentine
Extensive(more than half the surface)distinct cavity with visible dentine
ICCMS
ppt page21
Caries detection
1st action
Most diagnostic tests are limit to specific
Visual -tactile method remains the principle method
Only acceptable gold standard is histological assessment(possible only post-extraction/In vitro)
for diasgosis of dental caries use of a ball-end probes, these are not used for probing lesion, only for the gentle detection of surface texture or for removing debris in the examination of clean and dry teeth
X-ray machine
the detection of very early demineralisation in proximal tooth surfaces and occlusal surfaces can be considered unreliable不可靠
not appropriate in early caries
when you see caries on X-ray is already 60-70% demineralization
Alternative Detection
Laser-induced Flourescence
Quantitative laser fluorescence(QLF)
trans-illumination(FOTI/DiFOTI)
Caries-disclosing dyes(Fuchsine:Acid-res)
Electrical impedance(conductivity)
Photothermal radiometry
Confocal laser fluorescence and Raman
FOTI devices are suitable for use for carious lesion detection on approximal surfaces
Light-induced fluorescence (DIAGNODENT)device is not sufficiently reliable for assessing carious lesions in pits and fissures of occlusal surfaces.
Quantitative laser fluorescence (QLF) device is sufficiently足夠可靠 reliable for assessing carious lesions in pits and fissures of occlusal surfaces.
Treatment
Flouride
Remineralisation of Enamel
The presence of fluoride during the remineralisation/
demineralisation cycle leads to its incorporation into the crystalline structure of the carbonated hydroxyapatite
not only decreases crystal solubility
but also increases the precipitation rate of enamel mineral in the presence of calcium and phosphate due to the lower solubility of fluorapatite.
The effect and penetration of fluoride into the tooth surface is dependent on the type of fluoridated product and the time of exposure.
The efficacy of intermittently間歇性 applied professional topical gels and foams as well as systemic fluoridation is questionable, and the use of high concentration fluoridated varnishes should be encouraged, even in children.
Amino-fluoride
Amine fluorides are rapidly distributed in the oral cavity due to
their surface activity
their slightly acidic pH
they form a long-lasting, stable calcium fluoride precipitate on the enamel
This layer acts as a pH-dependent fluoride reservoir and exerts a long-term protective action under cariogenic conditions.
CARIES PROTECTION toothpaste gives superior protection against caries for permanent teeth.
Reduction of enamel solubility
A remarkable fluoride uptake of dental enamel surface after amine fluoride application has been observed in several studies.
Antiglycolytic action抗糖酵解作用
Amine fluoride also inhibits the metabolic activity of bacteria,
resulting in an effective reduction of their acid production.
Silver Diammine Fluoride
is a combination of silver
nitrate and sodium fluoride (Ag(NH3)2F)
inhibits carious lesion progression by its interaction with bacteria
Braga et al. 2009 investigated the effect of SDF in arresting enamel carious lesions in pits and fissures of permanent molars for up to 30 months. The results were no different from those achieved by plaque control through tooth brushing and the use of glass- ionomer sealant; two approaches which are largely used for enamel carious lesion management
Same results can be obtained using Ozone, Photodynamic and CHX
The role of Ca/PO
Increased concentrations of calcium would also increase the retention of fluoride in the plaque biofilm by increasing calcium-bridging
higher concentration of salivary proteins and peptides can improve the effectiveness of calcium and phosphate to stabilise in the oral environment (Biomimetic仿生 - remineralisation)
The effectiveness of fluoride to remineralise enamel and obtain net mineral gain is limited by the bio-availability of calcium (Ca) and phosphate (PO) ions
click to edit
Biomimetic關於或表示模仿生化過程的合成方法
Casein Phosphopeptide酪蛋白磷酸肽
have the ability to stabilise high concentrations of Ca and PO in metastable solution
a multi-phosphorylated protein present in milk
Amorphous calcium phosphate complexes
bind to Ca and PO to form clusters
preventing the growth of seed crystals to the critical size required for nucleation (nano-crystals) and phase transformation/crystallisation
providing a ready source of ionic calcium and phosphate提供現成的離子鈣和磷酸鹽源
In order to manage caries lesion (minimising the solubility of enamel), tooth surfaces should be exposed to supersaturated levels of calcium, phosphate and fluoride
NOT FOR PREVENTION
In amelogenesis imperfecta MIH在牙釉質發育不全(Casein Phosphopeptide-Amorphous calcium phosphate complexes)
MIH( enamel and dentine are softer than normal.)
attrition
exposed dentine
atypical cavities or complete coronal distortion
severe discomfort with cold stimulation
In vivo Replica Technique (SEM) and In vitro Biopsies (ESEM/EDX)
Although the lack of in vivo studies protocols with CPP-ACP, it may help functional restorative techniques in treated MIH molars and aesthetics in untreated incisors.
Air-Polishing and bioactive powders
This technique uses a pressurised stream of small bioactive particles (Bioglass or Bicarbonate) to polish the demineralised lesions and in pits and fissures
Typical Air Abrasion system
Particle diameter 27-90 μm
Powder flow rate 0.7-4.2 g/min
Air pressure 15-25 psi
Operating distance from tooth 1-2 m
Nano-Hydroxyapatite and Enamel remineralisation
The prevention and biomimetic treatment of early demineralisationlesions, particularly in individuals at high risk for developing caries may be performed by the application of nano-hydroxyapatite (nHA)
nHA could biomimetically repair damaged enamel through deposition onto natural tissue or even possibly by filling up defects and micropores on demineralised teeth
This would result in significant improvement of mechanical properties and enhancement of the remineralisation effect
HOWEVER (Limitations)
nano-HA promotes preferential remineralisation of the outer enamel caries lesion, but full remineralisation is not achievable under neutral conditions.
Under acidic conditions nHA can significantly accelerate the rate, depth of penetration, and extent of remineralisation of artificial incipient lesions.
Prevention of Occlusal Caries
A perfect case of early caries lesion treatment
- Sound enamel in kids
- Very early lesions in enamel
Pits and Fissure Sealants/Bioglass Air-Polishing
Sealing aims to modify patent pits and fissures into smooth surfaces that are protected from bacterial colonisation and exposure to fermentable substrate
The strategy is effective is for preventive measure and to arrest non-cavitated enamel carious/demineralisations
A high-viscosity GIC/RMGIC is indicated for use with the sealant technique due to the “remineralising” and antibacterial properties (Fluoride releasing)
Air-abrasion before pits and fissure sealing
This technique uses a pressurised stream of small bioactive particles (Bioglass or Bicarbonate) to polish the demineralised lesions and in pits and fissures
Typical Air Abrasion system
- Particle diameter 27-90 μm
- Powder flow rate 0.7-4.2 g/min
- Air pressure 30-50 psi
- Operating distance from tooth 0.5-2 mm
Materials available for therapeutic restoration: Glass-Ionomer Cements (GICs) and RMGIC
Conclusion
GIC and RMGIC are widely used in restorative dentistry, due to their self-adhesive and fluoride-releasing properties.
anti-caries /antibacterial properties
Fluoride can be released out without affecting the physical properties of cement.
fluoride is released from GIC at the time of mixing & lies with in matrix
Biocompatibility
Pulpal response to GIC is favorable.
• Pulpal response is mild due to
High buffering capacity of hydroxyapatite.
Large molecular weight of the polyacrylic acid ,which prevents entry into dentinal tubules.
Before any remineralisation protocol remember the treatment of the “surface zone” of the demineralisation lesion
Use of varnish with high content fluoride and Ca/PO
Biomimetic phosphoproteins to regulate the mineral precipitation of Ca/PO and Fluoride
Resin infiltration to mask and protect white spots; nano-apatite or nano-fluoro-apatite to remineralise the lesions too.
Pits and fissures sealing using air-abrasion, possibly with bioactive glass
✓ Use of bioactive sealants for Ca/PO and F release and antibacterial properties