口腔預(yù)防醫(yī)學(xué)：Pit-and-fissure sealants

1、Pit-and-fissure sealantsPit and fissure sealants were first reported byCueto and Buonocore1 in 1967 and are widelyrecommended and used in dentistry today.Dental caries in pit and fissures of childrenEpidemicsprevalence: dental caries on the occlusal surfaces 50.9% 67 years old 44% 1214 years old 65%

2、Fluorides prevention not so effective Susceptibility of Dental caries in pit and fissuresAnatomy of occlusal surfaces habitat for bacterialToo deep to clean even for professionalsOrganic plug, food residues, plaque block the pit and fissures, preventing the penetration of fluorideThin layer of ename

3、l vulnerable to dental caries Anatomy of occlusal surfacesClassification of pit and fissuresV shape, shallow, wide pit and fissures easy to cleanI shape, deep, narrow pit and fissures food and bacterial traps, difficult to clean Development of dental caries on pit and fissuresInitial caries on the s

4、idesExtended to the floorTriangle lesionAdvanced lesion History of prevention Prophylactic odontotomypreparation of a class I cavity, amalgam restorationProphylactic odontoplastyerase of deep pit and fissures by a round burPit and fissure sealant History of pit and fissure sealant 1st generation: 36

5、5nm ultraviolet radiation, long operation time, poor effect2nd generation: Bis-GMA, chemically solidified3rd generation: 430490nm visible light, convenient and good effect 3M Consise sealant4th generation: fluoride release Pulpdent sealantIndications for use of sealantsSEALRecently erupted teeth (le

6、ss than 4 years)MolarsDeep, retentive, narrow pits and fissuresTeeth showing signs of softening or opacity in pit or fissureOcclusal or smooth surface lesions on other teeth; no proximal cavitated lesions on tooth to be sealedPatient receiving appropriate systemic or topical fluoride therapy or both

7、 and still caries-activeIndications for use of sealantsDO NOT SEALTeeth that have remained caries free 4 yrs; staining is usually present in pits and fissuresTeeth not fully erupted and covered by gum Premolars except when patient is caries-activeWell coalesced fossae and grooves; wide, easily clean

8、ed groovesProximal cavitated lesion on tooth to be sealed; cavitation of occlusal ( tooth will require restoration)Patients water supply is fluoride deficient; patient is not cooperating in recommended caries-preventive program (restoration of pits and fissures is preferred)Components of sealantsRes

9、in baseBis-GMAThinner (dicrease the viscosity) methyl methacrylate (MMA) et al.Initiator self-cure light-cure (430490nm visible light)Filling (increase the compressive strenth, rigidity and abrasive resistance)Color (easy to identify)Acid-etch techniqueFirst introduced by Buonocore in 19553538% phos

10、phoric acid30 seconds for permanent teeth60 seconds for primary teeth higher organic composition higher acid resistance Acid etching transforms the smooth enamel into an irregular surface and increases its surface free energy. When a fluid resin-based material is applied to the irregular etched surf

11、ace, the resin penetrates into the surface, aided by capillary action. Monomers in the material polymerize, and the material becomes interlocked with the enamel surface. The formation of resin microtags within the enamel surface is the fundamental mechanism of sealant-enamel adhesion.Acid-etch techn

12、iqueEnamel etching results in three different micromorphologic patterns:Involves the dissolution of prism cores without dissolution of prism peripheriesThe peripheral enamel is dissolved, but the cores are left intactLess distinct than the other two patterns. It includes areas that resemble the othe

13、r patterns and areas whose topography is not related to enamel prism morphology.Clinical proceduresTeeth cleaningAcid-etchWashing and evaporationSealant applicationSolidify of sealantsExaminationClinical proceduresTeeth cleaning cleaning teeth thoroughlyslow speed hand piece, mini dental brush or ru

14、bber cap, pumice powder or dentifrices without fluoridecausions: no lipidic cleanser or abrasive with fillingserasing suspicious caries lesions if necessaryClinical proceduresAcid-etch35% phosphoric acid, 2/3 of teeth cusps slope, permanent teeth 30s, primary teeth 60s,(20s for permanent or primary

15、teeth)Cautions:gently mix to guarantee contacting with fresh acid,no contamination of the acid-etching surfaces,chalk appearanceClinical proceduresWashing and evaporationwashing thoroughly to wipe off acid and reaction producetion, evaporation by compressed air or absolute alcoholCautions:no contami

16、nation of the acid-etching surfaces,chalk appearanceClinical proceduresSealant applicationSelf-cure sealants: mixing for 10s to 15s, apply in 45s.Light-cure sealants: apply on acid-etched surfaces, fully penetration of sealant into the fissures, enough thickness to provide enough compressive strenth

17、, rigidity Clinical proceduresSolidify of sealantsself-cure sealants: 12 minutes light-cure sealants: 430490nm visible light, 1mm distance, 2040sClinical procedures6. Check and adjust occlusion if necessarysolidify, adherence, air bubble, missing fissures, overmuch sealant, occlusion adjustmentexami

18、nation after 3 months, 6 months or 1 year interval,re-application if lost Clinical effectivenessClinical evaluationretention rate = teeth with sealants retained/all the teeth examinedrelative effectiveness of decreased dental caries =(teeth with dental caries in the control teeth with dental caries

19、in the sealant group) / teeth with dental caries in the control 100%Clinical effectivenessSealants, by providing a physical barrier, inhibit microorganisms and food particles from collecting in pits and fissures. Sealants are highly effective in preventing dental caries in pits and fissures of teeth

20、 when applied by trained operators. Sealant should be placed on pits and fissures of childrens and adolescents permanent teeth when it is determined that the tooth or the patient is at risk of developing caries. Fissure sealing can be recommended as a caries preventive measure.Judit S. Fissure seali

21、ng. A review, Fogorv Sz. 2008 Aug;101(4):137-46.Other informations related to clinical effectivenessThe retention rate of sealants on maxillary teeth is lower than that of mandible teethThe retention rate of sealants on premolars is higher than that of molarsMost of disengagement occurs in the first

22、 6 months and re-application of sealants increase the caries prevention effectThe success of sealant varies depending on choosing teeth, operators skill, working attitude, etc.Systematic evaluation of clinical effectivenessClinical effectiveness of resin sealants to permanent teethThe relative carie

23、s risk reduction pooled estimate of resin-based sealants on permanent 1st molars was 33% (relative risk = 0.67; CI = 0.55-0.83). The effect depended on retention of the sealant. In conclusion, the review suggests limited evidence that fissure sealing of 1st permanent molars with resin-based material

24、s has a caries-preventive effect. The evidence is incomplete for permanent 2nd molars, premolars and primary molars and for glass ionomer cements.Mejare I, et al. Caries-preventive effect of fissure sealants: a systematic review. Acta Odontol Scand. 2003 Dec;61(6):321-30. Systematic evaluation of cl

25、inical effectivenessClinical effectiveness of resin sealants to permanent teethResin sealants are effective in preventing dental caries on occlusal surfaces of permanent teeth. The evidence is incomplete for primary teeth. Clinical effectiveness of glass ionomer (GIC) sealants Evid Based Dent.2010;1

26、1(1):10. doi: 10.1038/sj.ebd.6400700.Glass ionomerand resin-based fissure sealants - equally effective? RESULTS:Out of 25 selected studies, 11 met the inclusion criteria (eight were trials and three were systematic reviews) with six of these being included in a meta-analysis. The pooled odds ratio w

27、as 0.96 (95% confidence interval, 0.62-1.49), indicating no difference in the caries-preventive effect ofglass ionomercements (GIC) and resin-based fissuresealantmaterial.Clinical effectiveness of glass ionomer (GIC) sealantsCONCLUSIONS:GIC and resin-based sealants exhibited significant caries-preve

28、ntive effects. Thisreviewfound no evidence that either material was superior to the other in the prevention of caries. Therefore both materials appear to be equally suitable as fissuresealantmaterials.Longevity of materialsDent Mater.2012 Mar;28(3):298-303. Longevity of materials for pit and fissure

29、 sealing-results from a meta-analysis.Longevity of materials98 clinical reports and 12 field trial reports were identified. Auto-polymerizing sealants had the longest observation time (up to 20 years) and were found to have a 5-year retention rate of 64.7% (95%CI=57.1-73.1%), which was estimated fro

30、m the meta-analysis model. Resin-based light-polymerizing sealants and fluoride-releasing products showed similar 5-year retention rates (83.8%, 95%CI=54.9-94.7% and 69.9%, 95%CI=51.5-86.5%, respectively) for completely retained sealants. Poor retention rates were documented for UV-light-polymerizin

31、g materials, compomers andglass-ionomer-cement-based sealants (5-year retention rates were 19.3%). Retention rates for UV-light-polymerizing materials, compomers andglass-ionomer-cement-based sealants were classified as inferior.CONCLUSIONS VERSUS SIGNIFICANCE:The results of this meta-analysis sugge

32、sted that resin-based sealants can be recommended for clinical use. The faster and less error-prone clinical application of light-polymerizing materials, however, makes them the preferred choice for daily dental practice.Longevity of materialsPLoS One.2013 Oct 23;8(10):e77103. Validity ofsealantrete

33、ntion as surrogate for caries prevention-a systematicreview.RESULTS:The risk of loss of complete retention ofsealantmaterials was associated with the risk of caries occurrence for resin but not for GIC basedsealants. The difference between RCR values of the twosealanttypes was statistically signific

34、ant (p0.05). The null-hypothesis was rejected.CONCLUSIONS:The current clinical evidence suggests that complete retention ofpit and fissure sealantsmay not be a valid surrogate endpoint for caries prevention as its clinical endpoint. Further research is required to corroborate the current results.Lon

35、gevity of materialsSystematic evaluation of clinical effectivenessCochrane Database Syst Rev.2013 Mar 28;3:CD001830. Sealants for preventing dental decay in the permanent teeth.CONCLUSIONS:The application of sealants is a recommended procedure to prevent or control caries. Sealing the occlusal surfa

36、ces of permanent molars in children and adolescents reduces caries up to 48 months when compared to nosealant, after longer follow-up the quantity and quality of the evidence is reduced. Thereviewrevealed that sealants are effective in high risk children but information on the magnitude of the benef

37、it of sealing in other conditions is scarce. The relative effectiveness of different types of sealants has yet to be established.Other issues related to pit and fissure sealantsThe susceptibility to dental caries after acid etchthe solubility of acid-etched teeth in acidic solution was similar to th

38、at of non acid-etched teeththe dental caries decreased even if the sealants disengaged.Contamination of saliva after acid-etchcontamination of saliva prevent the formation of resin microtag disengagement of sealants or invading of bacterials dental cariescompressed airrubber and cotton rollsre-appli

39、cation of acid after exposure to saliva for 160sOther issues related to pit and fissure sealantsThe sealing of early dental caries in pits and fissures1. acid etching kill some of microorganisms in pits and fissures 2. sealants preventing the nutrition supplement of bacteria3. less than 3% bacteria

40、survived can produce acidearly dental caries in pits and fissures stopped after sealingSealant restorationThe sealant restoration is indicated primarily on the occlusal surfaces of permanent molars and premolars and may also be indicated for primary molars. They are most appropriate when the prepare

41、d cavity in a pit or fissure is small and discrete. Larger cavities would be more appropriately restored with amalgam or a posterior composite whilst smaller cavities may be restored with sealant alone.D. C. Hassall and A. C. Mellor, The sealant restoration: indications, success and clinical techniq

42、ue. British Dent Journal, 2001, 191(7): 358-62Sealant restorationSuccess depends on retention of the overlying sealant and if this is fully retained it is unlikely that any residual caries will progress. Conclusion: sealant restorations are the optimum restoration in small and discrete occlusal cavi

43、ties.D. C. Hassall and A. C. Mellor, The sealant restoration: indications, success and clinical technique. British Dent Journal, 2001, 191(7): 358-62Factors influence the use of pit and fissure sealantPit and fissure sealants are effective in caries preventionPit and fissure sealants are more cost-e

44、ffective than restorationsThe retention time of pit and fissure sealants is similar to that of amalgam restorationPit and fissure sealants are less painless and hurtlessPit and fissure sealants can be carried out by DSA and the cost is lower However, pit and fissure sealants still underdevelop.Facto

45、rs influence the use of pit and fissure sealantWhy?Attitude of the dentistslack of acknowledgement and interestno enough oral health education to the children and their parents regarding the use of pit and fissure sealantDevelopment of pit and fissure sealantThe caries prevention effect of combinati

46、on with pit and fissure sealant and fluoride rinses is better than that of fluoride rinses alone.Adding fluorides into sealants may lead to fluoride release and increase the effectiveness of caries prevention.Water-proof resins are used as sealants.GIC is used as sealants.New developments of sealant

47、sEur J Paediatr Dent.2016 Mar;17(1):17-23.Evaluation of shear bond strength, penetration ability, microleakage and remineralisation capacity of glass ionomer-basedfissuresealants.RESULTS:The Fuji Triage exhibited the lowest microleakage and unfilled area proportion (p0.05). The highest shear bond st

48、rength was calculated with Fuji VII EP (p0.05). The fluoride content for all treatment groups was significantly different when remineralisation values were compared to demineralisation (p0.05).CONCLUSION:Both the Fuji Triage and Fuji VII EP yielded compatible and satisfactory results and allfissuresealantsused in this study are sufficient as anti-caries agents.New developments of sealantsInt J Pa