Fluoride Releasing Restorative Materials

Published on February 2017 | Categories: Documents | Downloads: 59 | Comments: 0 | Views: 256
of 23
Download PDF   Embed   Report

Comments

Content

 

CONTENTS

Fluorides 1. Intr Introd oduc ucti tion on . 2. History. 3. Av Avai aila labi bili lity ty.. 4. Sources. 5. App Applica lication tion and optimal optimal intak intake e values values.. a) Systemic b) Topical c) Self ap applied lied 6. Absorp sorpti tio on. 7. Excre xcrettion ion . 8. Storage. 9. Me Mech chan anis ism m of act actio ion. n.   Fluoride releasing material and their effects. 1. Rest Restorat oration ion failure failure and its sequela sequelae. e. 2. Se Secon conda dary ry ca carie ries s and iits ts featu feature re 3. Dia Diagn gnosi osis s of seco second ndary ary cari caries. es. 4. Fac Factor tors s influe influenc ncing ing FF- relea release. se. 5. F- recharge.

6. Pl Plaq aque ue and and flu fluor orid ide. e. 7. Mechanism of action(in relation to material).

8. Anti Antimicro microbial bial and F-releasi F-releasing ng mater materials ials 9. Flu Fluori oride de a and nd adj adjace acent nt ttoo ooth. th. 10. Review of various F-relea F-releasing sing restorative materials materials Introduction

 

Dental caries is one of the most common and per historic diseases occurring in human beings, and it is prevalent in developed, developed, developing, and underdeveloped underdeveloped countries. countries. But once restored, the principal reason for restoration failure is secondary caries in both the permanentt and primary dentitions. Secondary permanen Secondary caries accounts for approximately approximately 60% of  all reasons for restoration replacement, regardless of restorative material type. Other  reasons include ○ ○ ○ ○ ○

material failure, tooth fracture or defect, endodontic involvement, prosthetic abutment use, Techn Tec hnica icall errors errors,, and and dete deterio riorat ration ion of aesth aestheti etic c quali quality ty with with toothtooth-co color lored ed restoratives.

But, in the modern era after understand the effect of fluoride and its preventing action on dental caries as such, which gave a whole new out look to the restoration of carious or  any defecti defective ve tooth tooth without without any fear fear of seconda secondary’s. ry’s. But again again the complex material material brings the complex understanding of its judicious use and technique. So, my presentation titled “fluoride relishing material” will fall under following heading : Relevance today today and then. then. (21st vs past)

Dental caries ✔ ✔ ✔

most prevailing pre historic infectious diseases exist in developed, developing and under developed counties

Once restored ✔ ✔

Secondary account for 60% Irrespective of material type

Other reason for restoration failure ✔ ✔ ✔ ✔ ✔ ✔

Material failure, Tooth fracture or defect, Endodontic involvement, Prosthetic abutment use, Technical errors, and Deterioration of aesthetic quality with tooth-colored restoratives.

FLUORIDES are the ultimate weapon in caries prevention But again the complex material brings the complex understanding of its judicious use and technique. Secondary caries and the past.

 



Proper condensation of gold restoration .



Secondary expansion of amalgam and resiliency of dentine came into play.



With the development of silicate ------the story continues.

Fluorides history 

Fluorine word is derived from the Russian word "flor" ----------à "flois" meaning destruction in Greek and from Latin word "fluor" word "fluor" that means to flow since it was used as a flux.

Fluorine (F) most reactive nonmetal Most electronegative element It combines with all elements, except oxygen and the noble gases, to form fluorides. history Sir James Crichton Browne in 1802 first to propose possible connection in dental health and fluoride. 1901 Dr.Fredrick Mckay of Colorado (U.S.A) discovered discover ed certain stains. ‘Shoe Leathery Leat hery Survey’ Surv ey’ by Dr.Trendle Dr.Tr endley y H.Dean .

Availability of fluoride 

13th trace elements the earth's crust. Highly reactive anion, atomic weight of 19, atomic number of 9. Found in biosphere, lithosphere, hydrosphere, atmosphere and in all living organisms. Chemically exist in the form of fluorides, chiefly as: 1. Fluorspar (CaF2) 2. Fluorapat Fluorapatite ite (Ca10(PO4)6F2) 3. Cryolite (Na3AlF6)

Sources of Fluoride

Water. Present in all ground water.(except in certain region)

 

Also derived from plants, marine animals and even dust particles. Fluoride content varies in different types of food, like: a) Tea -97 ppm. b) Certain types of fishes -84.5 ppm. c) Potatoes -6.4 ppm. Fluoride Application 

Optimum Fluoride intake Depending upon the mean maximum daily temperature: ✔

Cold climate 1.2 ppm



Summer season or temperate climate 0.7 ppm

Calculation of Optimum Level of Fluoride   ✔

ppm fluoride = 0.34/E



E = -0.038 + 0.0062 X temp, in °F (E is estimated water intake)

Topical fluoride- Three methods.

1.First method- Application of fluoride solution. 2.Second method- Use of a concentrated fluoride rinse. 3.Third method- Tray technique, Usually 8% SnF2 (19,360 ppm) and

2% NaF (9,040 ppm) is used.

Self applied topical flouride

Concentration ranges from 1,000- 1,500 ppm of fluoride. Sodium fluoride, sodium monofluorphosphate are added but not the stannous fluoride. Frequent source of fluoride in low concentration can inhibit demineralization and enhance remineralization.  

Absorption of Fluoride

Readily absorbed into the body.

 

Stomach, through passive absorption. Can also occur from the lungs by inhalation. The solubility of inorganic fluorides in the diet and its calcium content. Bone deposition of fluoride occurs to the extent of 50% in growing children but only 10% in adults Fluoride is not protein-bound and occurs as free ion in the plasma . The volume of distribution is 0.5–0.7 litre/kg Excretion of Fluoride 

Urine, feces and sweat. It occurs in traces in milk, saliva, hair and tears. Urinary fluoride level is regarded as one of the best indices of fluoride intake.

Storage of Fluoride

Fluoride is stored in the hard tissues of the body. Fluoride uptake depends upon the amount ingested and absorbed. The duration of fluoride exposure and the type, region and metabolic activity of the tissue decide its storage factor.

Fluoride toxicity chronic toxicity 

1. Skel Skelet etal al fluo fluoro rosi sis s an and d 2. Dent Dental al fl fluo uoro rosi sis. s. Skeletal fluorosis –

 

1. Joint stiffness and osteosclerosis (milder forms),

2. Calcification Calcification of ligaments, ligaments, muscle muscle wasting, wasting, osteoporosis, osteoporosis, and and neurologi neurologic c deficits (severe forms). Symptomatic after about 10 years of fluoride exposure at least 10 mg/day. Dental fluorosis _  1. Diffuse Diffuse opacit opacities ies on the the enamel enamel surface surfaces s of the teet teeth. h. 2. Notewort Noteworthy hy becau because se o off cosmeti cosmetic c concer concern n May be associated with increased porosity. porosity may stained or coalesce into discrete pits. Dental fluorosis occurs as a result of high fluoride ingestio ingestion n in early life, primarily during the maturation phases of enamel development  Acute toxicity 

Highly concentrated fluoride ingestion can have toxic effect. Toxic dose- 8 mg F per kilogram body weight could result in toxic effects. Acute lethal dose- 32 mg to 64 mg F per kilogram body weight could result in death. Toxic effects on ingestion 5 mg to 8 mg per kilogram body wt Treatment of acute fluoride toxicity Treatment ranges from 1. Preventi Prevention on of furthe furtherr absorptio absorption n by ingesti ingestion on of milk milk 2. 5% calcium gluconate

3. Supp Supple lemen mental tal oxyg oxygen en thera therapy py 4. Gastric levage.

5. Activ Activate ated d charco charcoal al ingest ingestion ion.. 6. Bloo Bloodd-pl plas asma ma dia dialy lysi sis s Mechanism Of Action of fluorides f luorides

1. 2. 3. 4. 5.

Increase Increase in enamel enamel resistan resistance ce OR reductio reduction n in enamel enamel solubility solubility.. Increase Increase in p post ost eruptive eruptive maturati maturation. on. Reminera Remineralizat lization ion of incipien incipientt le lesion sions. s. Interfere Interference nce with plaque plaque microorga microorganism nism.. Modifica Modification tion in tooth tooth morpholo morphology. gy.

Increased enamel resistance OR reduction in enamel solubility

 

Dental caries involve dissolution of enamel from acid produced by bacteria plaque. As lactic acid , propionic acid, formic acid. Fluoride forms the fluorapatite, which is less soluble mineral. This reduced solubility is the cause of the caries prevention. Increase in post eruptive maturation.

In this case fluoride help in increased Remineralization rate of the hypomineralized. Both the mineral and the organic material are deposited from saliva. Remineralization of incipient lesions.

Fluoride help to Remineralization of the demineralized area. Interference with plaque microorganism microorganism..

High concentration of fluoride is bactericidal 200 ppm or more. Low concentration it is bacteriostatic. Fluoride in plaque inhibit bacterial enzyme, causing acid metabolism. Fluoride mainly interact with the bacterial cell well in aerobic and anaerobic condition their by causing the disruption of the matabolism. Modification in tooth morphology

Studies shows that during tooth development fluoride cause the slightly smaller tooth and with shallow fissures

Restoration failure and its squelae

2˚ is the cause of 50% to 60% of restorations failure. Restorations life varies as per restorative material. Amalgams have max. service period.   Restoration Restoratio n fails, increases the size of the cavity by 0.52 mm. When no caries is present by 0.25 mm. This implies that the replaced restoration width will be larger by 0.5 to 1.04 mm.

Secondary caries

 

Secondary is defined as caries detected at the margins of an existing restoration . It may have an inactive arrested lesion, an active incipient lesion, or a frankly cavitated lesion.

Only when marginal gaps are greater than or equal to 250 micron can secondary caries be identified clinical and microscopically. secondary caries has certain features.

Interproximal margins (>90% of failed amalgams, >60% of failed composite resins). Secondary caries is seen as a white spot (active), or a brown spot (inactive) lesion. A high proportion of secondary caries is located along the cervical and amalgam restorations impart color changes due to corrosion. Tran-illumination may be helpful with tooth-colored restorative materials.

Diagnosis

Diagnosis of secondary caries is dependent on following features. 1. vi visu sual al insp inspec ecti tion on,, 2. tacti tactile le sensati sensation on with judic judicious ious explo explorer rer usage, usage, and and 3. radiographic interpretation.

Whenever a restorative material is placed, there is a possibility for a microspace (gap) to be formed between the restorative material and the cavosurface enamel, dentin, and cementum.

Secondary caries and materials 

The ability of a material to resist secondary caries development is dependent on 1. complete removal of carious tissue. 2. formation of an intimate cavosurface restorative interface with minimal to no

microspace, and 3. release of caries protective agents (fluoride, metal ions, antimicrobials, acidic

ions) to the adjacent cavosurface and outer tooth surface.

 

Prevention is better then cure.

fluoride regimen implementation (rinses, gels, fluoridated toothpastes); Antimicrobials Antimicrob ials (chlorhexidine); (chlorhexidine); fluoride-releasing restorative material; Dietary review. Recaldent and ACP-CCP rigime

Fluoride releasing restorative material

Today, there are several fluoride-containing dental restoratives available in the market including 1. Varnishes 2. Sealents

3. gl glas asss-io iono nome mers rs,, 4. resinmodified glass-ionomer cements, 5. polyacid-modified composites (compomers), composites 6. and amalgams. and many more….

 

Different matrices and setting mechanisms of the products shows their fluoride release capability. Antibacterial and cariostatic cariostati c properties is associated with the amount of fluoride released. Fluoride may be released from dental restorative materials as part of the setting reaction. It can also be added to the formulation with the specific intention of fluoride release. Fluoride releasing components have included 1.

Fluoroaluminosilicate Fluoroalu minosilicate glasses (FAG),

2. Sta Stann nnou ous s fl fluo uorid ride e (S (Snf2 nf2), ), 3. Org Organ anic ic amin amine e fluori fluoride des s (CA (CAFH) FH) and and 4. Ytt Ytterb erbium ium flu fluori oride de (ybf2) (ybf2).. Factors influencing the release of fluorides

The release of fluoride is a complex process. It can be affected by several intrinsic variables, such as 1. formulation and fillers .

2. comp composit osition ion and pH-valu pH-value e of of saliva saliva,, 3. plaque an and 4. pellicle formation.

It was shown that factor like 1. powd powder–l er–liqui iquid d ratio ratio of two-pha two-phase-sy se-system stems, s, 2. mi mixi xing ng proc proced edur ure, e, 3. curi curing ng time time and and 4. the amoun amountt of of expo exposed sed are area a 5. different storage media affected the fluoride release.

The highest release is found in acidic and demineralizing–remineralizing regimes and lowest in saliva. In acidic media it increases because decrease in pH increases the dissolution of the material, leading to fluoride release

 

Adhesives or bonding agents when applied increases short and long term fluoride release. Bleaching and brushing does not affect the fluoride release. Fluoride recharge

“Recharging” is to maintain level of fluoride release. FROSTEN et al. found the phenomenon in GIC and called it “topping up effect” Fluoride reservoir ►►permeability ►►permeability of filling material. Glass-ionomers is best fluoride reservoir then others. Because of loosely bound water. Exogenous sources of fluoride act as reservoir, 1. flu fluori orida dated ted dent dentifr ifrice ices, s, 2. mouth rin rinses ses 3. high high-do -dose se flu fluori oride de gels gels and and 4. Varni rnishe shes. In oral environment saliva and plaque has a role in fluoride uptake.

Plaque and fluorides Plaque is ≡ caries development, But this organic film may act as a fluoride reservoir. Only small concentrations of fluoride in plaque, saliva, or calcifying fluids are necessary to shift the equilibrium. Remineralization begins with only 0.03 ppm fluoride. Antimicrobial activity of fluoride

Dental plaque fluoride, releases hydrogen fluoride from the plaque into the bacteria. Hydrogen fluoride inside the bacteria acidifies the bacterial cytoplasm and leads to release of  fluoride ions. Bacterial metabolism enzymes as 1. enolase, 2. acid phosphatase, 3. pyrophosphatase, 4. pyrophosphorylase,

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close