Restorative and Oral Rehab Flashcards
T/F:Primary teeth may be more susceptible to restoration failures than permanent teeth
True
Differences between primary and permanent teeth w/ respect to cavity preparation
Primary teeth: restore smaller carious lesions because of
- thinner enamel and dentin;- pulps larger in relation to crown (pulp involvement occurs more rapidly);
- pulp horns closer to DEJ
Also……
- enamel rods in gingival 1/3 extend in occlusal direction (no need to bevel gingival margin)
- greater constriction of crown at CEJ (more prominent cervical constriction, extensive gingival extension can lead to loss of gingival floor)
- broader, flatter contact areas (makes clinical diagnosis of proximal caries more difficult)
- whiter in color (need lighter composite shades)
- shallower pits and fissures
- narrower occlusal table
Incomplete excavation (either one-step or stepwise) results in (fewer/more) pulp exposures and (fewer/more) s/s pulpal disease compared to complete excavation.
Fewer, fewer
Pulp exposure occurred (more/less) frequently from complete excavation compared to stepwise excavation.
More
There is evidence of a (decrease/increase) in pulpal complications and post-op pain after incomplete caries excavation compared to complete.
decrease
T/F: The risk of permanent restoration failure was greater for incompletely excavated teeth compared to completely excavated.
False. Risk for permanent restoration failure similar for incompletely and completely excavated teeth.
T/F: Higher rates of success in maintaining pulp vitality in permanent teeth was found with one-step/partial excavation compared to stepwise/two-step excavation.
True According to Maltz study (RCT) which compared stepwise to partial excavation in permanent molars. Suggests that there is no need to re-open the cavity and perform a second excavation.
Is there evidence to suggest not removing caries at all prior to restoring?
Yes, surprisingly! Two RCTs suggest no excavation can arrest dental caries so long as a good seal of the final restoration is maintained
What % of caries in permanent posterior teeth is in pits/fissures?
80-90% 44% in primary teeth
A Cochrane review found that sealants placed on the occlusals of permanent molars of kids reduced caries up to ___ months compared to no sealant.
48(4 yrs) Overall effectiveness in preventing dental decay – 71%
Sealants result in what % of caries reduction after 1 year?
86% caries reduction after 1 year!
Sealants result in what % caries reduction after 4 years?
58%
Sealants reduce caries risk in permanent 1st molars by what %?
33% (Mehare et al) 50% cochrane review
Sealing both sound surfaces and non-cavitated enamel lesions is warranted because…
Sealants lower the amt of viable bacteria by at least 100 fold and reduced the number of lesions with any viable bacteria by about 50%
T/F: You should not provide sealants if follow-up cannot be ensured.
FalseWhy? Because caries risk for sealed teeth that have lost some or all sealant does NOT exceed the caries risk for never-sealed teeth.
T/F: It is recommended to mechanically prepare the tooth prior to sealant placement.
FALSEIt is NOT RECOMMENDED. There is evidence that mechanical preparation may make a tooth MORE prone to caries in case of resin-based sealant loss. Sealant placement methods should include careful cleaning of the pits and fissures without mechanical tooth preparation.
Which is better – toothbrush prophylaxis or handpiece prophylaxis – to clean the tooth prior to sealant placement?
Toothbrush Evidence shows that teeth cleaned prior to sealant application with a TOOTHBRUSH prophylaxis exhibited SIMILAR OR HIGHER success rate compared to those sealed after handpiece prophylaxis.
How much enamel can be removed through rubber cup prophy?
.6-4.0 microns of the outer enamel
What kind of primers enhance sealant retention?
Acetone or ethanol solvent based primers, especially single bottle system NOT water-based primers – drastically reduce retention of sealants want low-viscosity hydrophilic material bonding layer, as part of or under the sealant – better for long-term retention and effectiveness
T/F: Resin-based sealants have better retention than glass ionomer-based sealants.
True, according to one meta-analysis and a Cochrane review BUT GI sealants exhibit good short-term retention comparable to resin-based at 1 year (therefore may be used as interim when moisture control compromises placement of resin sealants) Also no difference between caries-preventive effects of GI and resin-based sealants.
T/F: There is sufficient data to support use of fissure sealants in primary teeth.
False Insufficient data:76% retention in 2.8 years; retention rate of GI sealants in primary molars 18% in 1.3 years and no difference in caries reduction
What do bonding agents do for sealants?
Increase bond strength minimize leakage
Can you seal over enamel lesions?
Yes. It can arrest the lesion and reduce progression.If caries is into dentin, must be treated.
What are the 3 indications for sealants?
- Previous history of caries/restorations on other occlusal surfaces
- Sound occlusal surface with deep pits and fissures
- Explorer tugback with no demineralization, opacities, or shadowing.
What is Resin infiltration? What acid is used to etch?
Newer approach to treating non-cavitated interproximal lesions (ICON) Goal is to arrest the progression of such lesions. Aim: allow penetration of a low viscosity resin into the porous lesion body of enamel caries Technique:uses a specialized matrix interproximally treat surface with hydrochloric aciddesiccate surface with air, ethanolvia capillary action and 2 application cycles, infiltrate an unfilled fluid resin to the extent of the DEJ or beyondpolymerize resin with light TECHNIQUE SENSITIVEMUST USE RDI NOT RADIOPAQUE
There is evidence in favor of resin infiltration as a treatment option for small, non-cavitated interproximal carious lesions in primary teeth.
False. Evidence in favor of resin infiltration for PERMANENT TEETH. *Most of the RCTs done on resin infiltration have potential conflicts of interest BUT RI versus placebo showed less lesion progression (32% lesion progression versus 70% in one study, another study 7% versus 37%). Potential consistent benefit in slowing the progression or reversing non-cavitated carious lesions
According to the FDA, amalgam is classified as a Class ___ device.
II “having some risk”, therefore designated guidance including warning labels re: possible harm of hg vapors, disclosure of hg content, contraindications for persons with known hg sensitivity; also noted that there is limited info re: dental amalgam and long-term health outcomes in pregnant women, developing fetuses and children <6yo.
There is strong evidence that dental amalgam is efficacious in the restoration of what kinds of cavities in primary and permanent teeth?
Class I and class II Success rates: Class I in primary teeth: 85-96% for up to 7 years, average annual fail rate 3.2% Class I in permanent teeth: 90-99% for up to 7 years Class II in primary teeth: amalgam expected to survive minimum 3.5 years and potentially in excess of 7 years, Class II in permanent teeth: amalgam = to composite in mean annual failure rate (2.3%), medium success rate of composite and amalgam are = after 10 years (92% composite, 94% amalgam)
Amalgam is an alloy of:
Silver tin copper zinc mercury (wetting agent) (50%)
2 phases of amalgam
Gamma-1 : strong Gamma-2 : Sn7-8Hg Very weak, corrosion prone – responsible for early fractures and failures Added copper to change this (Sn7Hg to Cu6Sn5) Tin sets the reaction, controls the dimensional changes
What is ideal % mercury?
42-54% >55% Hg weakens amalgam All mercury is chemically bound and non-reactive after amalgamation All studies show no neurologic effects of dental Hg
Zn in amalgam serves what purpose:
Acts as oxygen scavenger, inhibiting oxide formation with Cu, Ag, Sn
Why would you use a bonding agent with amalgam?
Seal against microleakage, may aid in mechanical retention(?)
What is creep?
Tendency of a material to deform under constant stress. Higher copper means less deformation/less creep
Corrosion
Deterioration (chemical or electrochemical) of amalgam at the surface / subsurfaceHigh copper means less corrosion
Tensile strength of amalgam is high or low?
Low – that’s why you need deeper cavity preparation Compressive strength higher for amalgam
If the prep extends beyond the proximal line angles of a primary tooth, is amalgam a good restoration?
No. Class I, II, V restorations in permanent posteriors Class I, V primary Class II primary where prep does NOT extend beyond the prox line angles
What are the survival rates of amalgam restorations in primary teeth after 2-5 years?
46-66% over 2-5 yrs Mean survival about 5 yrs if placed at age 4-5Younger age at placement => lower mean survival time
Resins have what components?
- Filler particles (hydrophilic) - Matrix = dimethacrylate resin/BisGMA (hydrophobic) - Silane coupling agent (bonds matrix/filler) - Pigments - Stabilizers - Polymerization inhibitor- Photoinitiator - Radioopaquing agents
What size are the filler particles in micro-, mini-, midsize, and macro- filled resins?
Micro <0.1 micron (highest polishability) Mini 0.1–1 micron Midsize 1 – 10 microns Macro 10 – 100 microns (greatest strength) Hybrid resins combine both Filler size affects polishability/esthetics, polymerization depth and shrinkage, and physical properties
Filler functions
- Reduce polymerization shrinkage - Decrease coefficient of thermal expansion - increase hardness (compressive strength) - improve wear - control translucency
4 Contraindications to resins:
- Class II primary tth extending beyond line angles or C II permanent tth extending beyond ½ B-L intercuspal width 2. difficult moisture control 3. kids needing large multisurface restorations in 1˚ molars 4. High risk – multiple caries and/or demin and who exhibit poor OH or poor compliance
What is the polymerization shrinkage of resins?
2.5 – 6% less shrinkage w/ RMGI liner shrink towards the strongest area of the bond bond strength of ≥ 17 mPa needed to overcome shrinkage stress incremental filling reduces stress lower filled resins shrink more
Categories of Resins
Traditional – non-silane treated quartz particles (8-12um); >80% filled Microfilled – silane treated colloidal silica particles (0.04-0.4 um); 50-60% filled Hybrid – silane treated colloidal silical and glass particles of varying sizes (0.04-1.5 um); 50-75% filled Nanofilled – silane treated silica/zirconium particles (0.005-0.01 um);75-80% (highly filled) *trend toward high level of fillers (nano), replacement of traditional monomers with larger m.w. monomers, addition of silorane monomer*bulk fill resins frequently nanofilled, low shrinkage, polymerization depth up to 5 mm
Rank the tensile strengths of small particle, hybrid, nano, traditional, and microfilled composites
Small particle (1-5µ) = hybrid (0.6-1µ) = nano (5-100µ) > traditional (8-12µ) > micro (0.04-0.4µ)
Rank the compressive strengths of small particle, hybrid, nano, traditional, and microfilled composites
Small particle (1-5µ) > hybrid (0.6-1µ) = nano (5-100µ) > micro (0.04-0.4µ) = traditional (8-12µ)
Rank the finishability of small particle, hybrid, nano, traditional, and microfilled composites
Nanofilled > Microfilled > hybrid > small particle > traditional Take homes: Traditional are not strong or polishable – bad Microfilled are not strong but decent polishability Nanofilled are the most polishable and somewhere in the middle for strength Small particle and hybrid are the strongest, with medium polishability Note: Handbook also talks about “fine particle” – high wear resistance, good mechanical properties, rougher surface than microfilled or hybrid
What % filler are flowable resins?
45 – 70% result in: - increased shrinkage - decreased wear resistance - decreased strength - decreased bond strength radio-opacity is an issue, especially if flowable is placed beneath composite in “sandwich” technique
BPA (Bisphenol A) is considered a toxin and it is recommended to minimize exposure to it. Is it present in dental composites and sealants?
Yes, present in most. FDA & ADA conclude that any low-level exposure from dental materials poses no known health threat
BPA can become part of resin/sealant in 3 ways:
- Direct ingredient 2. Degradation by-product of bisGMA or bisDMA 3. trace material Recommendations to reduce BPA exposure: clean/rub new resins with cotton roll, pumice; rinse with water/suction, use RDI Trace amounts of BPA derivatives are released from dental resins thru salivary enzymatic hydrolysis
BPA may be detectable in saliva up to ___ hours after resin placement.
3
BPA derivatives may pose health risks attributable to their ________ properties.
Estrogenic
Class I and II composite and amalgam restorations show an overall success rate of __% after 10 years for both materials
90% Heintz study rubber dam use increases restoration longevity
T/F: After 7-10 years, the replacement rate for composite is higher than amalgam.
True but no different at 3.4 years
Enamel and dentin bonding agents decrease what two things for composite restorations?
Marginal staining and detectable margins
Secondary caries rate ___x greater for composite versus amalgam
3.5
What properties of glass ionomers make them favorable for use in children?
- chemical bonding to both enamel and dentin - thermal expansion similar to that of tooth structure- biocompatibility - uptake and release of fluoride (can act as a reservoir of fluoride) - decreased moisture sensitivity compared to resin
Fluoride release can occur for at least ___ year after placement.
1 year
T/F: Conventional glass ionomers are recommended for class II restorations in primary molars.
False But there is evidence in favor of GI cements for class I restorations in primary teeth
T/F: A systematic review supports use of RMGIC in small to moderate size class II cavities in primary molars.
True RMGIC class II restorations able to withstand occlusal forces on primary molars for at least 1 year RMGIC more successful than conventional GI as a restorative material Dentin conditioning improves success rate of RMGIC Cavosurface beveling leads to high marginal failure – not recommended “Strong evidence that RMGIC for class I restorations are efficacious, and expert opinion supports class II restorations in primary teeth”
T/F: There is sufficient evidence to support the use of RMGIC as a long-term restoration in permanent teeth
False insufficient evidence “insufficient evidence to support the use of conventional or resin-modified GI cements as long-term restorative material in permanent teeth”
T/F: There is strong evidence that ITR/ART using high viscosity GI cements has value as multi-surface restoration for both primary and permanent teeth
False has value as a SINGLE surface temporary restoration. Single surface ART restorations showed high survival rates for both primary and permanent teeth, but with regard to multi-surface ART restorations, there is conflicting evidence.
AAPD recommendations for glass ionomer use:
- Luting cement: SSCs, ortho bands, brackets (ltd) - Cavity base/liner- 1˚ tth: Class I, II, III, V * - Perm tth: Class III, IV in high risk pts or difficult isolation - Caries control/high risk patients - restoration repair - ITR- sealant * This slide was old. Evidence against for class II primary teeth! And “strong evidence” for in class I permanent teeth based on ART studies. This is from the Comprehensive Review – not all in line with the most recent 2014 AAPD Clinical Guideline for Restorative.
What is the recommended primer for GI placement?
10% polyacrylic acid 10-15 seconds => H2O rinse to remove smear layer but leave tubules plugged. For successful GIC: - proper dentin conditioning - wait 3-5 minutes before finishing - protect with varnish or sealant, no pressure for 1 hr
GIC liquid is ______ acid and powder is mainly _________.
GIC liquid is an aqueous solution of polyacrylic acid and powder is mainly aluminosilicate.
Resin modified glass ionomer is what % GIC + % resin?
80% GIC 20% LC composite resin
RMGI sets in what 3 ways?
- Acid base rxn (self cure) 2. Chemical polymerization rxn (resin cure) 3. photoinitiated (light cure)
How do RMGI compare to GIC?
- strength/solubility, esthetics lies in-between GIC and resin composite - F- release equal to GIC, but decreases over time, can be recharged - molecular bond to tooth structure ≥ GIC - less microleakage than GIC
What is a compomer?
Polyacid-modified resin-based composite - resin-modified with hydrophilic monomers - low F- release - LC + acid/base rxn - need primer/bond, acid etch - weaker, wears more than composites/RMGI - easy to use/handle
What does the new guideline have to say about compomers?
- Compomer tends to have better physical properties than GIC and RMGIC in primary teeth - no significant difference in cariostatic effects of compomer versus GI/RMGI - Compomers in class I primary teeth similar longevity to amalgam, but needed more replacement (recurrent caries) - In Class II compomer restorations in primary teeth, the risk of developing secondary caries and failure did not increase over a two-year period in primary molars. “Compomers can be an alternative to other restorative materials in the PRIMARY dentition in class I and class II restorations;” “There is not enough data comparing compomers to other restorative materials in PERMANENT teeth of children”
Compomers are ____% strontium fluorosilicate glass and the average particle size is ___ micrometers.
72%, 2.5
Why can compomers be useful in pediatric dentistry?
- Ability to release fluoride (buffers acidic environments) - esthetic value- simple handling properties
What is the composition of SSCs?
Chrome Steel 18-8: Chromium 18%, Ni 8%, carbon 1-20% Nickel-chrome: Ni 77%, Chromium 15%, Iron 7% (3M ESPE) Chromium reduces corrosion
What is success rate of SSCs?
88% Lower when placed over pulp-treated teeth
What are the indications for SSC placement in primary and permanent teeth?
- Restoration of primary and permanent teeth with extensive caries, cervical decalcification, and/or developmental defects (e.g. hypoplasia, hypocalcification) 2. When failure of other available restorative materials is likely (e.g. interprox caries extending beyond line angles, pts with bruxism) 3. following pulpotomy or pulpectomy 4. for restoring a primary tooth that is to be used as an abutment for a space maintainer 5. for the intermediate restoration of fractured teeth 6. for definitive restorative tx for high caries-risk children 7. used more frequently in patients whose tx is performed under sedation or GA
Average five year failure rate of SSC compared to class II amalgam?
7% SSC 26% amalgam Greater longevity of SSCs compared to amalgam for the tx of carious lesions in primary teeth
T/F: There was a non-significant difference in the survival rate for teeth restored with RMGI/composite versus SSC on primary pulpotomy-treated teeth.
True 95% SSC, 92.5% RMGI/resinper Atieh study Another study showed significantly less restoration failure and improved pulpotomy success w/ SSC (80%) versus amalgam (60%) after 1 year However, a systematic review did not show strong evidence that preformed metal crowns were superior over other restorations for pulpotomized teeth
What are the reasons for gingivitis associated with preformed metal crowns?
Inadequately contoured crowns;residues of set cement remaining in contact with the gingival sulcus
What are the indications for SSCs on permanent teeth?
- Teeth with severe genetic/developmental defects - Grossly carious teeth - traumatized teeth- tooth developmental stage or financial considerations that require semi-permanent restoration instead of a permanent cast restoration There is evidence supporting the use of SSCs in permanent teeth as a semi-permanent restoration for the tx of severe enamel defects or grossly carious teeth.
The main reasons for SSC failure on permanent teeth are:
Crown loss; perforation
Why is esthetic restoration of the primary anterior teeth challenging?
- Small size of the teeth - Close proximity of the pulp to the tooth surface - Relatively thin enamel - Lack of surface area for bonding - Issues related to child behavior
There is expert opinion that suggests use of _____ as a treatment option for class III and V restorations in 1. primary and permanent teeth 2. primary teeth when adequate isolation difficult
- resin-based composites2. RMGI
Indications for full coronal restoration of carious primary incisors:
- Caries is present on multiple surfaces 2. The incisal edge is involved 3. There is extensive cervical decalcification 4. Pulpal therapy is indicated 5. Caries may be minor, but oral hygiene is very poor 6. The child’s behavior makes moisture control very difficult
Retention of strip crowns after 3 years?
80% completely retained, 20% partially retained, none completely lost (another study showed 80% retention as well after 24-74 mo.)
Can you use ZOE under resins?
Nope. Eugenol inhibits polymerization
What is the depth of acid etch penetration?
10 – 75 microns (smear layer 1-5 µ) bond strength to enamel is about 20 Mpa or 3000 psi
What is the smear layer and how deep is it?
1-5 µ Includes dentin chips, debris, denatured collagen
What is a conditioner for?
Remove/modify smear layerincrease permeability demin underlying dentin EDTA, phosphoric acid, maleic acid, nitric acid
What is a primer for?
Provides micro-mechanical retention to the modified smear layer and dentin Hydrophilic wetting agent, penetrates collagen meshwork to create hybrid layer
What does an adhesive do?
Bonds primer to composite resin.
What are the different generations of bonding agents?
3rd 4th – primer separate from bond 5th – prime N Bond together Self-etching adhesives (L-pop)
Primary vs permanent teeth - smear layer - hybrid layer - acid etching
1˚ smear layer removed more easily - 1˚ thicker hybrid layer (primer + tubules) - 1˚ dentin more reactive to acid etch w/deeper demin (need less time to etch)
What is a liner (in a filling)?
<0.5 mm cement or resin coating to achieve physical barrier to bacteria & byproducts or for therapeutic effect such as antibacterial or pulpal anodyne effect. GI (vitrebond) CaOH (Dycal) – CaOH stimulated reparative dentin as a liner, but has unfavorable properties, so cover it with vitrebond.
What is a base?
Used for bulk buildup and/or for blocking out undercuts for indirect restoration. GI ZOE cements zinc phosphate cements
What are some surface treatments to enhance osseointegration of implants?
Plasma spraying
Acid etching
grit blasting/acid etch
Tx with hydroxyapatite leads to biointegration (direct biochemical bond of bone to implant surface independent of mechanical interlocking)
Problems with use of implants in children
Research supports removal of third molars under what conditions?
- when pathology is associated(e.g. cysts, tumors, caries, infection, pericoronitis, perio, detrimental changes to adjacent teeth or bone) and/or
- the tooth is malpositioned or nonfunctional (i.e. unopposed tooth)
*No evidence to support or refute the prophylactic removal of disease-free impacted third molars.
Incidence of pathology w/ impacted third molars
20%
internal root resorption, periodontal bone loss, resorption of the distal of second molar, pericoronitis
Mandibular molars exhibit more pathology or abnormalities
25% in study cited by Sonis comp. review
Mesioangular and horizontal impactions at highest risk!
What does ‘laser’ stand for?
Light amplification by stimulated emission of radiation.
Photon delivered in a beam with exact wavelength unique to the medium. Monochromatic.
Target tissues differ in their affinity for specific wavelengths of laser energy.
Laser energy targets tissue that has water in it, raising it above 100˚C.
Water then vaporizes, resulting in soft tissue ablation.
The primary effect of a laser within target tissues is photothermal.
What is a CO2 laser good for?
Incising, excising, and coagulating soft tissue.
(wavelength poorly absorbed by hydroxyapatite)
historically the oldest type of laser used for soft tissue procedures
What is the diode laser used for?
Soft tissue surgery, without affecting hard tissues around it.
(diode laser has aluminum, Iridium, gallium, arsenic)
What is the ND-YAG laser made from and what is it for?
Neodynmium ions and crystal of yttrium, aluminium, garnet.
Used for soft tissue surgery, coagulation and hemostasis (absorbed well by hemoglobin)
(minimally absorbed by hard tissue)
What are the erbium lasers made of and used for?
Er: YAG – erbium, yttrium, aluminum, garnet
Er,Cr:YSGG – erbium, chromium, yttrium, scandium, gallium, garnet
Soft tissue procedures
remove caries & prepare enamel, dentin, cementum, and bone
direct & indirect pulp capping
primary tooth pulpotomies (comparable to FCS)
root canal disinfection
Which lasers provide the best hemostatic ability?
CO2, diode, and Nd:YAG lasers all have capability of effectively incising tissue, coagulating and contouring tissue.
Erbium lasers have soft tissue capabilities but not as good hemostatic ability.
What is LF laser fluorescence used for in dentistry?
Detecting occlusal caries – emitted fluorescence correlates with the extent of demineralization in the tooth.
E.g. Diagnodent (portable diode laser-based system)
Can indicate the proportional amt of caries present
Used as an adjunct.
Not for use to detect caries under resins or sealants (unreliable due to intrinsic fluorescence from the sealant material).
Which lasers are successful for removal of caries and preparation of teeth?
Nd:YAG, Er:YAG, Er,Cr:YSGG
also successful for indirect and direct pulp capping
Erbium lasers are the predominant lasers for hard tissue prep
Dental lasers have also been used for pulpotomies and root canal disinfection, with success rate similar to Formo pulpotomies
How do lasers benefit the pediatric patient during soft tissue surgery?
Selective and precise interaction with diseased tissues
Less thermal necrosis of adjacent tissue than electrosurge.
Hemostasis achieved w/o sutures
Wound healing faster w/less post-op discomfort/need for analgesics
Little to no LA required for most soft-tissue tx
Reduced chair time
lasers decontaminate/bactericidal on tissues → less abx post-op
Provide relief from pain/inflammation associated with aphthous ulcers/herpetic lesions
How do erbium lasers remove caries?
Caries have higher water content than healthy tissue so they are removed effectively.
Nd:YAG & Erbium lasers have been shown to have analgesic effect on hard tissues, eliminating injections and the use of LA during tooth preparations.
What is a concern regarding treatment with laser of viral lesions in immunocompromised patients?
The potential risk of disease transmission from laser-generated aerosol exists
**Wavelength-specific protective eyewear should be provided and consistently worn at all times!!
Intrinsic stains can be caused by what 5 things?
- Blood borne pigments
- Drug
- Trauma
- Hypoplasia/hypomineralization
- Excessive F-
What blood borne pigment causes purple, green, black, grey?
Purple-brown : porphyria
Green – bile duct defects
Black, grey – neonatal hepatitis – bilirubin
Bluegreen-brown – Rh incompatibility (erythroblastosis fetalis) – bilirubin, biliverdin
gray – anemias, hemosiderin
red, gray, black – trauma / necrosis
What is the threshold for tetracycline staining?
21 – 26 mg/kg for 3 days
Primary teeth more intense
Tetracycline HCl most stain
Doxycycline / oxytetracycline least likely to stain teeth
Darken with more exposure to UV light
Extrinsic stains can be caused by lots of things like:
Bacteria
- green (aspergillus, bacillus pyocaneus),
- orange (chromogenic bacteria, poor OH, easy to remove)
- brown/black (chromogenic, much less common, hard to remove)
Foods
SnF
CHX
FeS – iron sulfide
tobacco
Ag2NO3 – silver nitrate
What the the 3 indications for internal/external whitening?
- discoloration from trauma (calcific metamorphosis or darkening with devitalization)
- irregularities in enamel color due to trauma or infection of the preceding primary tooth
- intrinsic discoloration staining (fluorosis, tetracycline staining)
Why would full arch bleaching during mixed dentition result in mismatched dental appearance?
Tooth color within an arch may vary significantly during mixed dentition due to difference in enamel thickness of primary and permanent teeth, leading to mismatched dental appearance once pt fully transitions
Advantages of in-office whitening or whitening products (custom trays) dispensed and monitored by a dental professional:
- An initial professional exam to identify causes of discoloration and clinical concerns with treatment (e.g.existing restorations and side effects)
- professional control and soft-tissue protection
- patient compliance
- rapid results
What is the range of strength of professional bleaching products?
10-38% Carbamide peroxide which is equivalent to 3-13% hydrogen peroxide
Carbamide peroxide is the most commonly used active ingredient in dentist-dispensed tooth bleaching products for home use
Home-use bleaching products contain?
Lower concentrations of hydrogen peroxide or Carbamide peroxide
What are the side effects of external bleaching vital teeth?
Tooth sensitivity and tissue irritation from ill fitting tray (rather than the bleaching agents); increased marginal leakage of an existing restoration
**Most research on bleaching done on ADULT patients
What % of people are sensitive following bleaching
8-66%
Side effects of internal bleaching of non vital teeth
External root resorption and ankylosis
Most common side effect of External bleaching a non vital tooth?
Marginal leakage of existing restoration
What is a degradation byproduct of hydrogen peroxide and Carbamide peroxide?
Hydroxyl free radical associated with periodontal tissue damage and root resorption
Due to concern of this radical and potential side effects from bleaching, minimizing exposure at the lowest effect [] is recommended
What is the best to bleach non vital teeth?
Sodium perborate and water
What two non vital bleaching agents in combo cause root resorption
Hydrogen peroxide and sodium perborate, or heated sodium perborate - study by Heithersay
