Restoration longevity
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Transcript of Restoration longevity
Restoration Longevity3.5b
Composite Resin
Amalgam
Amalgam Restorations [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
Amalgam Restorations [1]
Advantages
• Low technique sensitivity
• High longevity & radiopacity
• High compressive strength
• Excellent wear resistance
• Ability to seal marginal spaces over time
Disadvantages
• Lack of aesthetics
• Increased tooth removal during tooth preparation
• Survival rates of between 55-95% over a 5 year period
Reasons for Amalgam Failure [2]
Technical work of dentist
Patient behaviour
Secondary caries Tooth fracture
Cervical overhangs
Marginal ditching
Not so much the material
Main reasons for failure of AMALGAM
Figure 1: Demonstrates Corrosion of the Amalgam Restoration [2]
Figure 1
Composite Resin Restorations [1, 2]
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
Composite Resin Restorations [2]
Advantages
• Good aesthetics
• Preservation of tooth tissue during prep
• Low thermal conductivity
Disadvantages
• More technique sensitive than amalgam
• Low durability in posterior teeth
Figure 2: Large posterior composite demonstrates marginal discolouration and wear [3].
Figure 2:
Longevity dependant on: [1, 4, 5]
•Plaque adheres better to resin-based composites than amalgam
Oral Hygiene
•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
Occlusal Factors
•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)
Preparation Type
Longevity dependant on: [1, 4, 5]
•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
Preparation Size
•Tooth must be isolated when using RBCs for effective moisture control as moisture contamination compromises the bond
•This is less critical for amalgam
Field Isolation
Longevity dependant on: [1, 4, 5]
•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
Tooth-Restoration Interface
•Age, gender, reason for restoration
•Oral hygiene, caries risk, parafunctional habits
•Levels of cooperation and compliance
Patient-Related Factors
Video Links - explain the failure of amalgam and composite fillings
Studies
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%)
Norway Study [4]
For BOTH amalgam and composite, the top
reasons for failure were:
• 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
Other failure reasons:
• 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
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
Cavities were either classI or II
Results showed:84% survival rate at
8 yearsAnnual failure rate of
2%
We can compare this with earlier reported annual failure rates in randomised long-
term longitudinal evaluations between
0.5% and 3%
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
placement
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 2
Failed/Defective 5
Sensitive/Painful 4
Open Margin 2
Total 84 6
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
Followed annually for oral
examination and bitewings
If restorations required replacing
= “failure”
Mean annual failure rate• 0.82% for amalgam• 2.21% for
composites
Comparing Long Term Survivalof Amalgam & Composite Restorations [2]
Bernado et al. Survival Rates
Main reason for failure for both types:
- Secondary caries
Risk was 3.5 times higher in composites vs. amalgam
Amalgam
Composite resin
0 20 40 60 80 100
94.4
85.5
Survival rate (%) over 7 years
Rest
ora
tive
Mate
rial
Comparing Long Term Survivalof Amalgam & Composite Restorations [2]
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.
5 yrs
10 yrs
0 10 20 30 40 50 60 70 80 90 100
89.6
79.2
91.7
82.2
Composite Amalgam
Survival rate (%)
Ye
ars
Po
st
Pla
cem
en
t
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
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
How long do direct restorations last? [8]
Burke, F. and Lucarotti, P. (2008)
Summary: Older patients have restorations with a shorter interval to re-intervention
10 Year Survival of Restorations by Patient Age
Burke et al. 2001 [9]
Reasons for resin composite replacement:
Resin
Com
posite
020406080
100
Secondary Caries
Fractured Restoration
Lost Restora-tion
Wear
Sensitivity Pulpal PainPerc
en
tag
e
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
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
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
restorations0% to 9% for direct
composites [12]
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.
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.