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Restoration longevity


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Restoration longevity

  1. 1. A direct restoration material composed of an alloy consisting of mercury, silver, copper or tin. Kolker et al estimated the average survival of amalgam restorations is 22.5 years Survival rate of 78% over a 5 year period
  2. 2. Advantages Disadvantages • Low technique sensitivity • Lack of aesthetics • High longevity & radiopacity • Increased tooth removal during tooth preparation • High compressive strength • Excellent wear resistance • Ability to seal marginal spaces over time • Survival rates of between 5595% over a 5 year period
  3. 3. Technical work of dentist Marginal ditching Patient behaviour Cervical overhangs Secondary caries Tooth fracture Not so much the material Main reasons for failure of AMALGAM
  4. 4. Figure 1 Figure 1: Demonstrates Corrosion of the Amalgam Restoration [2]
  5. 5. A direct restoration material composed of a monomer and polymer mix of light curable resins. Main reasons for failure were secondary caries and fracture of restoration Bernardo et al concluded the overall risk of failure due to secondary caries was 3.5 times higher in composite than amalgam restorations Survival rates of between 55-95% over a 5 year period
  6. 6. Advantages Disadvantages • Good aesthetics • More technique sensitive than amalgam • Preservation of tooth tissue during prep • Low durability in posterior teeth • Low thermal conductivity
  7. 7. Figure 2: Figure 2: Large posterior composite demonstrates marginal discolouration and wear [3].
  8. 8. Oral Hygiene • Plaque adheres better to resin-based composites than amalgam Occlusal Factors • High occlusal function is associated with reduced longevity • Amalgam has greater wear resistance than composites (useful in heavy occlusion or para-function) • However in normal occlusal function composites perform well Preparation Type • Class I and II amalgam restorations have survival time between 25-70 years; not representative of the population, as it was on highly motivated patients (dental students and staff)
  9. 9. Preparation Size • Failure rate increases for both materials as cavity size and no. of walls involved increases, however this is more pronounced in RBCs • 14.2% of large amalgam restorations needed to be replaced after 5 years as opposed to 19.8% of composite restorations Field Isolation • Tooth must be isolated when using RBCs for effective moisture control as moisture contamination compromises the bond • This is less critical for amalgam
  10. 10. ToothRestoration Interface PatientRelated Factors • Amalgam corrosion products fill the space between the tooth and restoration … marginal seal improves with time • Composite polymerisation shrinkage - compromises the marginal seal and increases the risk of secondary caries • Age, gender, reason for restoration • Oral hygiene, caries risk, parafunctional habits • Levels of cooperation and compliance
  11. 11. explain the failure of amalgam and composite fillings
  12. 12. Norway Study [4] Followed 27 dentists in Norway – looking at all of their class II restorations (4030 in total), for over 4 years. Focus was on adolescents 13 amalgams failed = 7.1% of the amalgams placed (lower than composite failure rate) 407 RBCs (a larger number were placed) = 12.4% Mean annual fail rate for: Amalgam (1.6%) & resin composite (2.9%)
  13. 13. Norway Study [4] For BOTH amalgam and composite, the top reasons for failure were: Other failure reasons: • 1. Secondary caries. Composites were much more susceptible: causing 73.9% of the failures. Results may have been affected by the adolescent focused study – their lifestyle increasing secondary caries risk • 2. Loss of the restoration • Amalgams: due to tooth fracture. Unlike amalgam composites crack before the tooth • Composites: due to marginal defects and poor approximal contact. Short term reasons: un-contoured restorations and porosities
  14. 14. Public Dental Health Service Study [5] Observed the longevity of resin composite ONLY Included 2881 patients with a mean age of 13.7 & 4355 restorations were included by 115 dentists Results showed: 84% survival rate at 8 years Annual failure rate of 2% Cavities were either class I or II We can compare this with earlier reported annual failure rates in randomised long-term longitudinal evaluations between 0.5% and 3%
  15. 15. Restorations by dental students study [6]   Measured longevity of 4009 restorations placed by dental students Summary:    Composite really is technique sensitive In the short term, Class II resin composites are failing at a rate 10 times higher than with dental amalgam Results:    6 amalgams (0.35% of amalgams) were replaced during 1 year 84 class II composites (3.6% of composites) were replaced during 1 year 21 composites of which were replaced in less than a month of
  16. 16. Restorations by dental students study [6] Reasons for Restoration Being Placed by Type of Restoration Reason for Failure Composite Amalgam Fracture 24 2 Missing 15 1 Void 15 1 Loose 7 Open Contact 7 Residual Caries 5 Failed/Defective 5 Sensitive/Painful 4 Open Margin 2 Total 84 2 6
  17. 17. Elliot, A. 2008 [7] 472 Portuguese children, aged 8-12 years, with dental caries in one or more posterior teeth Randomised to receive either an: - Amalgam or - Composite restoration If restorations required replacing = “failure” Followed annually for oral examination and bitewings Mean annual failure rate • 0.82% for amalgam • 2.21% for composites
  18. 18. Comparing Long Term Survival of Amalgam & Composite Restorations [2] Bernado et al. Survival Rates - Secondary caries Risk was 3.5 times higher in composites vs. amalgam Restorative Material Main reason for failure for both types: Composite resin 85.5 Amalgam 94.4 0 20 40 60 80 100 Survival rate (%) over 7 years
  19. 19. Opdam et al. Survival Rate Findings: The number of surfaces restored affects the longevity Summary of Bernado & Opdam studies: After 7 years, both materials have a high longevity. Years Post Placement Comparing Long Term Survival of Amalgam & Composite Restorations [2] 82.2 79.2 10 yrs 91.7 89.6 5 yrs 0 20 40 60 Survival rate (%) Composite Amalgam 80 100
  20. 20. Patient factors influence on restoration failure [7] 32 GDPs were asked to record the reason for placement / replacement of 3196 restorations from a list of potential reasons The restoration age, material & class were also recorded Restorations placed: 54% amalgam, 32% composite, 8% compomer, 7% glass ionomer Reasons for placement / replacement: 29% secondary caries, 28% primary caries, 10% margin fracture, 7% tooth fracture, 6% non-carious defects Mean age of restorations at failure = 7.1 years
  21. 21. How long do direct restorations last? [8] Burke, F. and Lucarotti, P. (2008) Data from 503,965 restoration placements were obtained from 80,000 adult patients (46% male, 54% female) Summary: Single surface amalgams have better survival rates than class II restorations 10 Year Survival of Amalgam Restorations
  22. 22. How long do direct restorations last? [8] Burke, F. and Lucarotti, P. (2008) Summary: Older patients have restorations with a shorter interval to reintervention 10 Year Survival of Restorations by Patient Age
  23. 23. Reasons for resin composite replacement: Percentage Burke et al. 2001 [9] 100 90 80 70 60 50 40 30 20 10 0 Secondary Caries Fractured Restoration Lost Restoration Wear Sensitivity Resin Composite Amalgam Pulpal Pain
  24. 24. Selection of dental materials & longevity of replaced restorations in Sweden [10] High caries risk patients  shorter longevity for resin based composites vs. low / moderate risk patients due to recurrent caries Larger restorations  show greater failure rates (class II = the most frequently replaced cavity) Restorations replaced by more experienced dentists are shown to have significantly longer longevity Longevity of restorations depends on: - Operator experience, patient caries risk, material characteristics Research suggests: Composites longevity is 6 years & amalgams longevity is 16 years
  25. 25. A 24-month Evaluation of Amalgam and Resin-Based Composite Restorations [11] 226 practitioners; 6,218 direct restorations. • 386 restorations failed (6.2 %) during the following 23.7 months Number of tooth surfaces restored helped predict subsequent restoration failure … restorations with 4 or more restored surfaces were more than 4 times more likely to fail Restorative material and tooth type were not associated significantly with longevity Older patient age was associated highly with failure (P<0.001). Failure rate for children was 4 percent, compared with 10 percent for people 65 years or older
  26. 26. Conclusion Correctly performed amalgam restorations in posterior teeth have higher longevity than resin composites These differences are more pronounced when: -The cavity is larger & -There are multiple surfaces involved [1] Annual failure rates in posterior stress-bearing restorations are: 0% to 7% for amalgam restorations 0% to 9% for direct composites [12]
  27. 27. References       1. Soares AC, Cavalheiro A. A review of Amalgam and Composite Longevity of Posterior Restorations. Rev Port Estomatol Med Dent Cir Maxilofac 2010;51:155-164 2. Is it the end of the road for dental amalgam? A critical review. J Conserv Dent. 2008 Jul-Sep; 11(3): 99–107. 3. Wilson NHF, Burke FJT, Mjo¨r IA. Reasons for placement and replacement of restorations of direct restorative materials by a selected group of practitioners in the United Kingdom. Quintessence International 1997;28:245–8. 4. Kopperud SE, Tveit AB, Gaarden T, Sandvik L, Espelid I. Longevity of posterior dental restorations and reasons for failure. European Journal of Oral Sciences 2012; 120: 539–548. 5. Pallesen U, Van Dijken JWV, Halken J, Hallonsten AL, Ho¨igaard R. Longevity of posterior resin composite restorations in permanent teeth in Public Dental Health Service: A prospective 8 years follow up. Journal of dentistry 41 (2013) 297–306 6. Overton JD, Sullivan DJ. Early Failure of Class II Resin Composite Versus Class II Amalgam Restorations Placed by Dental Students. Journal of Dental Education March 1, 2012 vol. 76 no. 3 338-340.
  28. 28. References       7. Elliot, A. (2008) The Risk of Failure is Higher for Composites than for Amalgam Restoration. Journal of Evidence Based Dental Practice. Volume 8, Issue 2: Pages 83-84. 8. Burke, F. and Lucarotti, P. (2008) How long do direct restorations placed within the general dental services in England and Wales survive? British Dental Journal 206 9. Burke FJT, Wilson NHF, Cheung SW, Mjo¨r IA. Influence of patient factors on age of restorations at failure and reasons for their placement and replacement. Journal of Dentistry 2001;29:317–24. 10. Sunnegardh-Gronberg K, Van Dijken J, Funegard U et al. Selection of dental materials and longevity of replaced restorations in Public Dental Health clinics in northern Sweden. Journal of dentistry 2009; 37 (9), pp. 673--678. 11. McCracken MS, Gordan VV, Litaker MS et al. A 24-month evaluation of amalgam and resin-based composite restorations. JADA 2013; 144, 583-593 12. Hickel R, Manhart J. Longevity of restorations in posterior teeth and reasons for failure. J Adhes Dent 2001;3(1):45–64.