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Dentists need to consider various factors when choosing restorative materials, with the longevity of restorations being one of the most important criteria. Replacement of failed restorations constitutes over 60% of operative procedures, leading to high annual costs. This literature review compares the survival rates of different restorative materials used for both direct and indirect restorations. A literature search was carried out using Pubmed to identify all articles on restorative materials published from 1974 to 2014, of which 22 were included in this review. For direct restorations, amalgam showed the highest survival rates (22.5 years), with an average survival rate of 95% over 10 years, followed by composite resins (90% over 10 years), and glass ionomer cements (65% over 5 years). For indirect restorations, gold restorations are still the "gold standard" with a 96% over 10 years survival rate, followed by porcelain-fused-to-metal crowns (PFM) (90% over 10 years), and all ceramic crowns (75-80% over 10 years). Amongst the ceramic restorations, eMax shows the longest survival rate (90% over 10 years), and Zirconia the lowest (88% over five years). The longevity of restorations depends on many factors, including: materials used, type of restorative procedure, patient parameters, operator variables, and local factors.
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Dentists need to consider various factors when choosing
restorative materials, with the longevity of restorations be-
ing one of the most important criteria. Replacement of failed
restorations constitutes over 60% of operative procedures,
leading to high annual costs. This literature review compares
the survival rates of different restorative materials used for
both direct and indirect restorations. A literature search
was carried out using Pubmed to identify all articles on re-
storative materials published from 1974 to 2014, of which 22
were included in this review. For direct restorations, amal-
gam showed the highest survival rates (22.5 years), with
an average survival rate of 95% over 10 years, followed by
composite resins (90% over 10 years), and glass ionomer
cements (65% over 5 years). For indirect restorations, gold
restorations are still the “gold standard” with a 96% over
10 years survival rate, followed by porcelain-fused-to-metal
crowns (PFM) (90% over 10 years), and all ceramic crowns
(75-80% over 10 years). Amongst the ceramic restorations,
eMax shows the longest survival rate (90% over 10 years),
and Zirconia the lowest (88% over five years). The longevity
of restorations depends on many factors, including: materi-
als used, type of restorative procedure, patient parameters,
operator variables, and local factors.
A wide variety of materials are used by dentists in the
restoration of teeth. Many factors need to be considered
by both the dentist and the patient when choosing the
optimal restorative material for each procedure, with the
longevity of that particular restorative material being one
of the most important.1, 2
Restoration success is the demonstrated ability of a resto-
ration to perform as expected, whereas the length of time
that a restoration survives (survival rate), is often used as a
measure of clinical performance. Replacing failed restora-
tions constitutes about 60% of all operative procedures car-
ried out by dentists, with estimated annual costs of around
$5 billion in the USA alone.1 Restorations have a limited
lifespan and once a tooth is restored, a “restorative cycle”
commences, where the restoration will likely be replaced
many times throughout the lifetime of the patient.3 Dentists
are obliged to inform their patients about the survival rates
of different materials and restorative procedures. This will
allow the patients to make informed decisions regarding
their treatment options. The United States Public Health
Service (USPHS) criteria have been used most widely to
determine the clinical performance of restorations. This
requires two independent examiners and uses a grading
system based on a number of observations (eg. retention,
colour match, secondary caries, etc.). For each observation
there is a grading from Alpha (perfect), Bravo (less perfect),
to Charlie (complete failure).1 The majority of the articles re-
viewed in this paper used these criteria in their evaluation,
with the main focus being on survival rates.
A wide variety of both patient and clinician variables will
influence the longevity of restorations.4 These include:
Caries index, where a high index is often associated with a
low restoration longevity, usually due to recurrent caries.5
Restoration size, with larger restorations having great-
er failure rates due to their greater surface area, making
them more susceptible to recurrent caries, fracture, and
restoration failures.5
Tooth position, with molars having lower restoration sur-
vival rates than anterior teeth.5 This relates to restorations
being larger on posterior teeth and sustaining greater oc-
clusal forces, affecting their longevity.
SADJ October 2015, Vol 70 no 9 p410 - p413
NA Fernandes1, ZI Vally2, LM Sykes3
The longevity of restorations -
a literature review
NA Fernandes: 1. BDS. Registrar, Department of Prosthodontics,
School of Dentistry, Faculty of Health Sciences, University of Pretoria.
ZI Vally: 2. BDS, MDent (Pros). Senior Specialist, Department of
Prosthodontics, School of Dentistry, Faculty of Health Sciences,
University of Pretoria.
LM Sykes: 3. BDS, MDent (Pros). Head of Clinical Unit and Associate
Professor, Department of Prosthodontics, School of Dentistry,
Faculty of Health Sciences, University of Pretoria.
Corre spondi ng author
NA Fernandes:
Department of Prosthodontics, School of Dentistry, Faculty of Health
Sciences, University of Pretoria. E-mail:
CEREC: Chairside Economical Restoration of Esthetic
FPD: Fixed partial dentures
GIC’s: Glass ionomer cements
PFM: Porcelain fused to metal
YST: Yttrium-stabilized tetragonal type
< 411
Clinician variables: more experienced clinicians have
higher restoration survival rates.
Patient parameters may also play a role. Studies found
that those who regularly change dentists had their resto-
rations replaced more frequently, while restoration failures
are highest among older patients and lowest in the 4-18
year age group. This may purely be due to older patients
having older restorations, however, caries incidence is
also higher in the elderly due to changes in their stoma-
tognathic system, impaired motor function, and reduced
salivary flow rates, amongst others.5
A literature search was undertaken using Pubmed in the
identification of relevant articles published from 1974 up
to and including 2014.The following keywords were used:
longevity, restorations, prosthodontics, crowns, all ce-
ramic, zirconia, CAD/CAM, amalgam, composite, lifespan,
survival. Twenty two articles have been included in this
review, which covers both direct and indirect restorative
materials as well as different manufacturing techniques.
This is still one of the most commonly used restorative ma-
terials in posterior teeth in some countries. It’s use is how-
ever declining due to higher aesthetic demands of patients
and their concerns over mercury toxicity.6 It has a unique
ability to seal itself over time by a phenomenon known as
“c ree p”,7 which has been defined as “the deformation of
a metal under a load that is below its proportional limit”.8
Dental amalgams have been shown to “creep” as a con-
sequence of low-frequency cyclic stresses resulting from
mastication and from thermal changes during ingestion of
hot and cold food. The material expands with internal cor-
rosion and phase changes, which will fill in the microscopic
space at the tooth-amalgam interfaces. The median surviv-
al time of amalgam has been estimated to be 22.5 years,2
with some studies showing annual failure rates of 3%.4
Composite resin
Early composite resin materials showed failure rates as
high as 50% after 10 years.2 This has drastically improved
with the introduction of newer products. These materials
can currently be classified as nanofilled, microfilled, or mi-
cro/nanohybrid materials with filler quantities varying from
42-55%. Of these, the hybrid composites performed the
best with annual failure rates of 1.5-2%, most often as
a result of restoration fracture.9 The major drawbacks of
these materials are polymerization shrinkage and polym-
erization stress. These have the potential to initiate fail-
ure at the composite-tooth interface which will result in
post-operative sensitivity and the opening of pre-existing
enamel microcracks. Newer low stress flowable base ma-
terials can overcome some of these problems by reducing
the amount of stress generated during polymerization (1.4
MPa compared with 4 MPa for other flowable compos-
ites).10 Such restorations should be followed up periodi-
cally for early detection of problems as once failures e are
initiated there is usually a rapid progression. The place-
ment of glass ionomer cement liners under composites
further improved their success rates and is now regarded
as a “gold standard” procedure especially in posterior
teeth. These cements resist caries formation in the adja-
cent tooth structure by maintaining the pH at levels above
those required for demineralization to occur.11 Current ap-
proaches have seen the introduction of new nanocom-
posite materials which release fluoride (F-), calcium (Ca2+),
and phosphate (PO4) ions. These calcium and phosphate
ions combine to form hydroxyapatite [Ca10(PO4)6(OH)2],
thus strengthening the tooth and combating secondary
caries.12 More studies and further development of these
new materials is however needed.
As mentioned, GIC’s make an excellent dentine replace-
ment as a lining or base when managing dentinal caries
but lack the physical properties needed to be used alone
for posterior restorations.2 In addition, they are more read-
ily lost interproximally where reduced saliva flow leads to
sustained low pH levels. Improved saliva flow on other
tooth surfaces helps restore the resting pH levels.11 These
materials are most effective buffers in acidic environments
and are also excellent luting agents. Their primary use is
for restoring Class V cavities, primary teeth, and in the ART
technique (atraumatic restorative treatment). In primary
teeth GIC’s have a 93-98% survival (over the longevity span
of the tooth), and a median survival of 30-42 months in per-
manent teeth. Their annual failure rate when used alone as
a restorative material is estimated to be 7%.4
Gold crowns and inlays
These are considered the “gold standard” against which
all other restorations are measured in terms of longev-
ity. The most common biological reason for their failure
is secondary caries, with retention loss being the most
common technical cause of default. Studies have shown
survival rates to range from 96% over 10 years, 87% over
20 years, to 74% over 30 years2 with a mean failure rate of
1.4% in the posterior permanent dentition.4
Porcelain fused to metal (PFM) crowns
These restorations have been repor ted to have a 97% 10
year survival rate.2 The majority of failures (65%) occur in
the anterior region (traumatic zone), and have been attrib-
uted to eccentric chewing forces, iatrogenic factors, ac-
cidents, and inadvertent contact with instruments during
surgical operations.13
Many different types of materials are available for all-ce-
ramic restorations. These can be chosen depending on the
properties required for a particular clinical situation (such as
aesthetic concerns versus the need for strength).2
The lifetime of these materials depends on the presence
of incidental cracks and their propagation under intra-oral
conditions.14 There are substantial differences in material
properties of the different ceramics, and thus they should
be considered separately.
Heat pressed, reinforced ceramics
Leucite-reinforced (eg. IPS Empress I) is reported to have
a 99% survival rate after 3.5 years, and a 95% survival
after 11 years, with better success reported for ante-
rior restorations.2 The IPS EMax system is comprised of
lithium disilicate (Li2O2SiO2) glass ceramic and zirconium
dioxide (ZrO2) materials which are suitable for pressing,
but can also be used with the CAD/CAM technologies.
This is a highly durable, very strong (360-400MPa flexural
strength) ceramic which can overcome some of the prob-
lems encountered with the chipping off of porcelain which
is commonly encountered in zirconia restorations. Studies
have shown their survival rates to be promising, with sys-
tematic reviews showing these to be in the region of 96%
after five years.15
Slip-cast glass-infiltrated ceramics
These include magnesia, alumina, and zirconia infiltrated var-
iants, with some studies showing survival rates of 92-100%
over five years for the magnesia and alumina variants.2
Metal oxide ceramics
These materials usually contain alumina or zirconia which
confer a toughness and superior fracture resistance but
also inferior aesthetics due to the inherent opacity found in
the high-density metal oxide crystals. Clinical studies have
shown Procera Alumina crowns to have success rates of
98% over 5 years, and 94% over 10 years.2 Zirconia has
been referred to as “ceramic steel” because of its superior
material properties. It is a crystalline dioxide of zirconium,
with mechanical properties similar to those of metals and a
colour similar to that of teeth. Zirconia crystals are organ-
ized into three different patterns: monoclinic, cubic, and
tetragonal. Zirconia ceramics used in dentistry are of the
Yttrium-stabilized tetragonal type (YST), which offer excel-
lent mechanical performance, strength, and fracture resist-
ance.16 This is possible by the “phase transformation effect
that these materials undergo (tension induced tetragonal-
to-monoclinic phase transformation).14 The net result is a
volumetric expansion which compresses cracks to prevent
propagation and enhances toughness to resist fractures.
Cracking and crazing of the veneering porcelain is of major
concern with some studies reporting this problem in as
many as 50% of cases after only two years.2 This is the
result of chewing forces being exerted on a very weak
90MPa feldspathic veneering porcelain, with the underlying
1000MPa zirconia substructure remaining intact, leading to
ultimate failure of the restoration. Such chipping can also
be attributed to rapid cooling protocols during fabrication
when firing the veneering feldspathic porcelain onto the zir-
conia substructure.14 This can be overcome to some extent
by ensuring slower cooling when the final restoration is re-
moved from the furnace.14 These restorations have survival
rates of 96% after two years, and 94% after four years,2 but
longer term clinical studies are still needed.
IPS-Empress inlays and onlays have been shown to have
survival rates of 96% after 4.5 years, and 91% after seven
years.2 With the introduction of CAD/CAM systems into
dentistry, in particular the CEREC (Chairside Economical
Restoration of Esthetic Ceramics) system, clinicians are
now able to use composite resin and ceramic materials to
fabricate indirect restorations.17 The CEREC 1 system was
mainly used for chairside fabrication of inlays and onlays
with long-term studies showing adequate survival rates of
97% over five years, and 90% over 10 years.2 The main
reasons for failure of these restorations were the result of
ceramic fracture (feldspathic porcelain), followed by frac-
tures to the underlying supporting tooth. With advances
in technology, the CEREC 2 system was capable of pro-
ducing inlays, onlays, full and partial crowns with survival
rates of 87% over seven years. The current CEREC 3 sys-
tem will manufacture veneers, shor t bridges, and implant
abutments, with survival rates for these being 95-97%
over five years.18
These can be divided into PFM and all ceramic. Studies
have shown survival rates to be 92% over 10 years, and 75%
over 15 years for the PFM type, 93% survival rates over five
years for zirconia, and 89% survival rates over five years for
all ceramic FPD’s. The sharp decline in survival rates after
10 years (PFM) can be attributed to material fatigue (of the
restoration or luting cements), recurrent caries, or retention
loss. FPD’s on implants have 87% 10-year survival rates.2
Longevity rates for these types of restorations vary widely,
with some studies showing 88% five year survival rates.
They are mostly lost due to de-bonding. Those in the
anterior regions seem to survive longer than those in the
posterior regions. Posterior restorations in the maxilla
survive longer than those in the mandible, possibly due to
greater masticatory forces being applied to the posterior
mandible causing more frequent de-bonding at this site.
< 413
When these restorations are re-bonded there are greater
failure rates, with 40% failing after their first re-bonding
and 60% failing after second re-bonding respectively.
Inappropriate case selection, and design flaws will not be
corrected by re-bonding these types of restorations, which
can explain their high failure rates.2
When restoring endodontically treated teeth, the use of
the sandwich technique, where a glass ionomer base is
covered with overlying composite resin, is the preferred
method for minimizing coronal leakage.19 When there is
inadequate tooth structure remaining, cast post and core
restorations have been found to have success rates of
90% over 10 years.20 If pre-fabricated posts need to used,
fibre-reinforced posts offer better long-term success
compared with metal posts, as these tend to cause more
root fractures due to their higher modulus of elasticity
compared with dentine.21 Sealer selection is also impor-
tant with AH-26 (epoxy sealer) offering better resistance
to leakage than ZOE (zinc oxide eugenol) based sealers.19
Endodontically treated teeth can have survival rates of
97% over 5-8 years if adequately restored.22
The longevity of restorations is dependent on a multitude
of factors making it difficult to compare success rates.
Based on current findings, we can, however, convey evi-
dence-based information to our patients regarding antici-
pated restoration survival rates. It is essential to establish
effective communication with our patients so that they can
make informed decisions regarding their treatment.
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... The newer composite materials are also more durable and, therefore, comparable to amalgam restorations in terms of strength. However, documented studies by Fernandes, Vally and Sykes (2015) and Hurst (2014) reveal that a composite restoration's survival rate is lower than an amalgam restoration in the long-term evaluation. 4,5 This is due to polymerisation shrinkage, which occurs during the setting reaction, resulting in microleakage underneath the restoration. ...
... However, documented studies by Fernandes, Vally and Sykes (2015) and Hurst (2014) reveal that a composite restoration's survival rate is lower than an amalgam restoration in the long-term evaluation. 4,5 This is due to polymerisation shrinkage, which occurs during the setting reaction, resulting in microleakage underneath the restoration. ...
... A study shows that composite resin restoration using adhesive techniques is useful when restoring cavities with up to 3 surfaces. However, the main downside of this type of restoration includes polymerization shrinkage/stress as well as sensitivity to moisture exposure [29]. Hence, the clinician's techniques/skill, as well as the patients' cooperation, are vital in the use of composite resin. ...
... Gold crowns are known as the gold standard for comparison. This is attributed to their longevity of about 96% over 10 years with a low failure rate of 1.4% [29] Porcelain fused to metal (PFM) crowns are metal crowns with a thin layer of ceramic coating its outer surface. In addition to their tooth-colored appearance, these crowns also have a good survival rate with a study by Behr et al [32] reporting an eight-year survival rate of 92.3% and 95.9% for anterior and posterior PFM crowns. ...
Full-text available
Objectives: The decision-making process is extremely important in the field of dentistry, including the field of endodontics, particularly in the selection of materials to be used for restoration. This review paper aims to summarize the factors to be taken into account before choosing a restoration for endodontically treated teeth, to review the different options of restorative materials, as well as to compare the conventional method of crowning endodontically treated teeth with the use of adhesive composite resins on these teeth. Data: In order to find relevant articles, search terms including composite resin, partial crown, full crown, root canal therapy were used. Sources: Sources were gathered from bibliographic databases including MEDLINE, National Centre for Biotechnology Information (NCBI), ResearchGate as well as ScienceDirect. Conclusion: The selection of coronal restorations requires the consideration of a multitude of factors. A clinician must always weigh in the benefits and drawbacks of each type of restoration as well as taking into account aesthetics and patient satisfaction.
... Indirect dental restorations include crowns, bridges, inlays and onlays [69]. The composition of this reconstruction can lead to more or less important artefacts. ...
Full-text available
Introduction Despite reduction of xerostomia with intensity-modulated compared to conformal X-ray radiotherapy, radiation-induced dental complications continue to occur. Proton therapy is promising in head and neck cancers to further reduce radiation-induced side-effects, but the optimal dental management has not been defined. Material and methods Dental management before proton therapy was assessed compared to intensity-modulated radiotherapy based on a bicentric experience, a literature review and illustrative cases. Results Preserved teeth frequently contain metallic dental restorations (amalgams, crowns, implants). Metals blur CT images, introducing errors in tumour and organ contour during radiotherapy planning. Due to their physical interactions with matter, protons are more sensitive than photons to tissue composition. The composition of restorative materials is rarely documented during radiotherapy planning, introducing dose errors. Manual artefact recontouring, metal artefact-reduction CT algorithms, dual or multi-energy CT and appropriate dose calculation algorithms insufficiently compensate for contour and dose errors during proton therapy. Physical uncertainties may be associated with lower tumour control probability and more side-effects after proton therapy. Metal-induced errors should be quantified and removal of metal restorations discussed on a case by case basis between dental care specialists, radiation oncologists and physicists. Metallic amalgams can be replaced with water-equivalent materials and crowns temporarily removed depending on rehabilitation potential, dental condition and cost. Implants might contraindicate proton therapy if they are in the proton beam path. Conclusion Metallic restorations may more severely affect proton than photon radiotherapy quality. Personalized dental care prior to proton therapy requires multidisciplinary assessment of metal-induced errors before choice of conservation/removal of dental metals and optimal radiotherapy.
... Studies have shown survival rates to be 92% over 10 years, and 75% over 15 years for the PFM type, 93% survival rates over five years for zirconia, and 89% survival rates over five years for all-ceramic FPD's. 29 ...
Traditional methods will be rendered obsolete, if not supplemented by current techniques and evidence. This requires a clinician to continuously recognize, scrutinize and consolidate the best available scientific literature in the field. Continuous improvement in the quality of research conducted, as well as reporting the findings should be encouraged to improve upon current and future treatments. This review showcases the most prominent controversies in prosthodontics and how the current evidence answers the questions. A PubMed, Met line and google scholar search with the keywords, Evidence-based dentistry and Evidence-based Prosthodontics was done from the year 1960-2021. Meta-analysis of randomized control trials and systematic reviews related to the evidence in complete dentures, fixed partial dentures, implants and prosthodontics were considered in the inclusion criteria. Literature reviews and case reports were excluded from the search. Evidence-based practice is a new level of sophistication in the practice of dentistry. Rather than considering the cost of material or the individual preference of the operator, choosing the right technique to maximize clinical efficiency should be based on scientific evidence.
... Materials 2021,14, 3102 ...
Full-text available
The objective of the present study was to evaluate the one-year clinical performance of lithium disilicate (LD) and zirconium dioxide (ZrO2) class II inlay restorations. Thirty healthy individuals who met the inclusion criteria were enrolled for the study. The patients were randomly divided into two study groups (n = 15): LD (IPS e.max press) and ZrO2 (Dentcare Zirconia). In the ZrO2 group, the internal surfaces of the inlays were sandblasted and silanized with Monobond N (Ivoclar, Leichsteistein, Germany). In the LD group, the internal surfaces of the inlays were etched with 5% hydrofluoric acid. The ceramic inlays were cemented with self-cure resin cement (Multilink N). Clinical examinations were performed using modified United State Public Health Codes and Criteria (USPHS) after 2 weeks, 4 weeks, 6 months and 1 year. The one-year survival rate was evaluated. In total, one failure was observed in the ZrO2 group. The survival probability after 1 year for the ZrO2 inlays was 93%, and for the LD inlays was 100%, which was statistically insignificant. The differences between both groups for most USPHS criteria (except for colour match) were statistically insignificant. Within the imitations of the present study, the lithium disilicate- and zirconia dioxide-based inlays exhibited comparable clinical performances. However, the colour and translucency match was superior for the lithium disilicate restorations.
... Several factors are to be considered while selecting the suitable restorative material for the procedure to provide optimal longevity [10]. The survival of the restorations depends upon various material factors. ...
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Background: Ceramic restorations can be fabricated by using traditional methods like heat-pressing as well as contemporary methods like Computer Aided Designing and Computer Aided Manufacturing (CAD-CAM). Existing evidence regarding the marginal adaptation of CAD-CAM fabricated ceramic inlays is contradictory. Aim: The main objective of the study is to determine the marginal gap widths of CAD-CAM fabricated lithium disilicate ceramic inlays in comparison with heat-pressed ceramic inlays using scanning electron microscopic examination. Materials and methods: Thirty-six intact, caries-free, maxillary first and second premolars were used in the study. Standardized class II disto-occlusal inlay cavities were prepared and were distributed into two groups of 18 specimens, each based on the method of fabrication. The two groups contained CAD-CAM (Group A), and heat-pressed ceramic inlays (Group B). In group A, the prepared inlay cavities were scanned with an intraoral scanner, designed, and milled from IPS e.max CAD blocks. In group B, the ceramic inlays were fabricated by manual impression making and lost wax technique using IPS e.max PRESS ingots and Programat EP 3010 furnace. The fabricated inlays were placed on the prepared cavities of the respective specimens. The scanning electron microscope was used to evaluate the marginal adaptation of specimens at 12 predetermined points for each specimen by a single examiner. The data were subjected to statistical analysis. Results: The mean marginal gap values for CAD-CAM group and heat-pressed were 83.27µm and 87.11µm, respectively. The CAD-CAM ceramic inlays exhibited better marginal adaptation than heat-pressed ceramic inlays with an insignificant difference between the two groups. Conclusion: CAD-CAM method of fabrication did not differ significantly from heat-press method when marginal adaptation property is considered. Moreover, all class II ceramic inlays exhibited minimal gap values. Clinical relevance: CAD-CAM fabricated ceramic inlays exhibited a comparable marginal adaptation with that of heat-pressed inlays. Thus, CAD-CAM fabrication is a better alternative to the conventional fabrication method, which can avoid multiple patient visits.
Carbon-based nanocomposites have been extensively studied for a number of years now for various applications. Such studies have been necessitated by the unique chemical and physical properties of nanocomposites that have enabled their applications in a number of areas. Nanocomposites, in general, are best defined as multiphase solid materials in which one of the phases has at least a single dimension with the size of a billionth of a meter (10–9 m). So far different processing techniques have been studied and/or employed for the preparation of carbon-based nanocomposites including noncovalent interaction, covalent reaction, electro and electroless plating, hydrothermal and solvothermal growth, electrochemical and electrophoresis deposition, photochemical reactions, and physical deposition and mixing. Other techniques, particularly for carbon nanotube (CNT)/polymer composites, include melt blending, solution blending, in-situ polymerization, electrospinning, and layer-by-layer assembly. Each method has its advantages and shortcomings. However, the shortcomings in the fabrication of specific nanocomposites can be improved by the adoption of the most suitable methods. This chapter is focused on the synthesis methods for CNT-based nanocomposites and their application in nanomedicine. There is no doubt, over the past decade, CNT-based nanocomposites have been widely studied and/or used in biomedical applications including drug delivery, cancer therapy, biosensing, bioimaging, bacterial inhibition, tissue engineering, and dental applications. However, their uptake and usability are still limited due to paucity of toxicity information and approval from international regulatory bodies. In view of the aforementioned, this chapter focuses on two aspects of CNT-based nanocomposites: First, the synthesis of the materials, and second, their biomedical applications.
Conference Paper
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ABSTRAK Kedokteran gigi restoratif menawarkan banyak metode untuk merestorasi gigi baik secara direk maupun indirek. Restorasi indirek pada gigi posterior berdasarkan bentuk dapat dibagi menjadi inlay dan onlay. Kebutuhan untuk melakukan restorasi adhesif pada gigi posterior tidak hanya terkait dengan tujuan estetika, tetapi juga untuk prinsip ekonomi, serta kemungkinan penguatan biomekanis dari struktur gigi yang tersisa. Beberapa bahan yang banyak digunakan sebagai restorasi indirek sewarna gigi pada gigi posterior adalah zirconia dan resin komposit. Berbagai bahan tersebut memiliki karakteristik masing-masing, terutama dalam segi fungsional seperti kekuatan mekanis, kekuatan fisik serta estetis. Untuk pemilihan bahan restorasi indirek gigi posterior, harus mempertimbangkan berbagai karakteristik masing-masing bahan, baik dari segi estetis maupun fungsional sehingga dapat ditentukan bahan yang tepat. Telaah pustaka ini bertujuan untuk memaparkan karakteristik restorasi indirek dengan bahan zirconia dan resin komposit pada gigi posterior. Telaah pustaka ini diambil dari penelitian 10 tahun terakhir (2011-2021) yang diambil dari google scholar dan pubmed dengan kata kunci restorasi indirek, inlay, onlay, zirconia dan resin komposit. Bahan zirconia memiliki kekuatan mekanis yang lebih baik dibandingkan bahan resin komposit, namun bahan komposit memiliki sifat estetis yang lebih baik dibandingkan dengan bahan zirconia untuk digunakan sebagai restorasi indirek pada gigi posterior.
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With the Internet facilitating access to vast amounts of free information, dental practitioners face providing treatment for an increasingly informed public. However, the available content is not filtered, and it can be difficult for patients to discriminate between research-informed evidence and "glamorised" material of dubious origin. Patients reasonably expect a return for their investment and want to know how long their treatment will last. Clinicians have an obligation to inform their patients so that they can make reasoned decisions about treatment options. Longevity data are also informative for health agencies setting service schedules for publicly funded treatment, and for determining settlements by insurers such as ACC. Historically, much of the prosthodontic treatment performed in practice has relied heavily on dogma, low-level anecdotal evidence, and clinical case reports. This paper considers the literature on fixed and removable prosthodontic restorations and provides a critical review which can be used practically as the basis for informing patients, and to assist decision-makers in making fair and appropriate judgements.
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In most retrospective studies, the clinical performance of restorations had not been considered in survival analysis. This study investigated the effect of including the clinically unacceptable cases according to modified United States Public Health Service (USPHS) criteria into the failed data on the survival analysis of direct restorations as to the longevity and prognostic variables. Nine hundred and sixty-seven direct restorations were evaluated. The data of 204 retreated restorations were collected from the records, and clinical performance of 763 restorations in function was evaluated according to modified USPHS criteria by two observers. The longevity and prognostic variables of the restorations were compared with a factor of involving clinically unacceptable cases into the failures using Kaplan-Meier survival analysis and Cox proportional hazard model. The median survival times of amalgam, composite resin and glass ionomer were 11.8, 11.0 and 6.8 years, respectively. Glass ionomer showed significantly lower longevity than composite resin and amalgam. When clinically unacceptable restorations were included into the failure, the median survival times of them decreased to 8.9, 9.7 and 6.4 years, respectively. After considering the clinical performance, composite resin was the only material that showed a difference in the longevity (p < 0.05) and the significantly higher relative risk of student group than professor group disappeared in operator groups. Even in the design of retrospective study, clinical evaluation needs to be included.
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SUMMARY Fracture resistance of inlays and onlays may be influenced by the quantity of the dental structure removed and the restorative materials used. The purpose of this in vitro study was to evaluate the effects of two different cavity preparation designs and all-ceramic restorative materials on the fracture resistance of the tooth-restoration complex. Fifty mandibular third molar teeth were randomly divided into the following five groups: group 1: intact teeth (control); group 2: inlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press, Ivoclar Vivadent AG, Schaan, Liechtenstein); group 3: inlay preparations, zirconia ceramic (ICE Zirkon, Zirkonzahn SRL, Gais, Italy); group 4: onlay preparations, lithium-disilicate glass-ceramic (IPS e.max Press); and group 5: onlay preparations, zirconia ceramic (ICE Zirkon). The inlay and onlay restorations were adhesively cemented with dual polymerizing resin cement (Variolink II, Ivoclar Vivadent AG). After thermal cycling (5° to 55°C × 5000 cycles), specimens were subjected to a compressive load until fracture at a crosshead speed of 0.5 mm/min. Statistical analyses were performed using one-way analysis of variance and Tukey HSD tests. The fracture strength values were significantly higher in the inlay group (2646.7 ± 360.4) restored with lithium-disilicate glass-ceramic than those of the onlay group (1673.6 ± 677) restored with lithium-disilicate glass-ceramic. The fracture strength values of teeth restored with inlays using zirconia ceramic (2849 ± 328) and onlays with zirconia ceramic (2796.3 ± 337.3) were similar to those of the intact teeth (2905.3 ± 398.8). In the IPS e.max Press groups, as the preparation amount was increased (from inlay to onlay preparation), the fracture resistance was decreased. In the ICE Zirkon ceramic groups, the preparation type did not affect the fracture resistance results.
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The purpose of this study was to investigate the possible influence of age on the longevity of tooth supported fixed prosthetic restorations, using a systematic review process. To identify relevant papers an electronic search was made using various databases (MEDLINE via Pubmed, EMBASE, The Cochrane Register of RCTs, the database of abstracts of Reviews of Effects-DARE), augmented by hand searching of key prosthodontic journals (International Journal of Prosthodontics, Journal of Prosthetic Dentistry and Journal of Prosthodontics) and reference cross-check. Assessment and selection of studies identified were conducted in a two phase procedure, by two independent reviewers utilizing specific inclusion and exclusion criteria. The minimum mean follow-up time was set at 5 years. The initial database search yielded 513 relevant titles. After the subsequent filtering process, 22 articles were selected for full-text analysis, finally resulting in 11 studies that met the inclusion criteria. All studies were classified as category C according to the strength of evidence. Meta-analysis was not possible due to the non-uniformity of the data available. The final studies were presented with conflicting results. The majority of the final studies did not report a statistically significant effect of age on fixed prostheses survival, whilst only one study reported poorer prognosis for elderly patients, and two studies reported poorer prognosis for middle-aged patients. The results of this systematic review showed that increased age of patients should not be considered as a risk factor for the survival of fixed prostheses. Although the majority of studies did not show any effect of age on the survival of fixed prostheses, there was some evidence that middle-aged patients may present with higher failure rates.
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This article reviews recent studies on: (1) the synthesis of novel calcium phosphate and calcium fluoride nanoparticles and their incorporation into dental resins to develop nanocomposites; (2) the effects of key microstructural parameters on Ca, PO(4), and F ion release from nanocomposites, including the effects of nanofiller volume fraction, particle size, and silanization; and (3) mechanical properties of nanocomposites, including water-aging effects, flexural strength, fracture toughness, and three-body wear. This article demonstrates that a major advantage of using the new nanoparticles is that high levels of Ca, PO(4), and F release can be achieved at low filler levels in the resin, because of the high surface areas of the nanoparticles. This leaves room in the resin for substantial reinforcement fillers. The combination of releasing nanofillers with stable and strong reinforcing fillers is promising to yield a nanocomposite with both stress-bearing and caries-inhibiting capabilities, a combination not yet available in current materials.
Implants verses root canal therapy is a current controversy in dentistry. The purpose of this investigation was to compare the success of each treatment, with minimal subjective grading. Outcome was determined by clinical chart notes and radiographs. Failure was defined as removal of the implant or tooth. Uncertain findings for implants were defined as mobility class I or greater, radiographic signs of bone loss, or an additional surgical procedure. Mobility, periapical index score of 3 or greater, or the need for apical surgery was classified as uncertain for endodontically treated teeth. Success was recorded if the implant or tooth was in place and functional. Implants were placed by periodontists in a group practice, whereas the endodontic treatments were performed by endodontists in group practice. Charts of 129 implants meeting inclusion criteria showed follow-up of an average of 36 months (range, 15-57 months), with a success rate of 98.4%. One hundred forty-three endodontically treated teeth were followed for an average of 22 months (range, 18-59 months), with a success rate of 99.3%. No statistically significant differences were found (P = .56). When uncertain findings were added to the failures, implant success dropped to 87.6%, and endodontic success declined to 90.2%. This difference was not statistically significant (P = .61). We found that 12.4% of implants required interventions, whereas 1.3% of endodontically treated teeth required interventions, which was statistically significant (P = .0003). The success of implant and endodontically treated teeth was essentially identical, but implants required more postoperative treatments to maintain them.
SUMMARY The aims of this retrospective clinical study were to compare the longevities of direct posterior amalgam restorations (AMs) and resin composite restorations (RCs) that were subjected to occlusal stresses and to investigate variables predictive of their outcome. A total of 269 AMs and RCs filled in Class I and II cavities of posterior teeth were evaluated with Kaplan-Meier survival estimator and multivariate Cox proportional hazard model. Seventy-one retreated restorations were reviewed from dental records. The other 198 restorations still in use were evaluated according to modified US Public Health Service (USPHS) criteria by two investigators. The longevity of RCs was significantly lower than that of AMs (AM = 8.7 years and RC = 5.0 years, p<0.05), especially in molars. The prognostic variables, such as age, restorative material, tooth type, operator group, diagnosis, cavity classification, and gender, affected the longevity of the restorations (multivariate Cox regression analysis, p<0.05). However, among the restorations working in oral cavities, their clinical performance evaluated with modified USPHS criteria showed no statistical difference between both restoratives. In contrast to the short longevity of RCs relative to AMs, the clinical performance of RCs working in oral cavities was observed to be not different from that of AMs. This suggests that once a RC starts to fail, it happens in a rapid progression. As posterior esthetic restorations, RCs must be observed carefully with periodic follow-ups for early detection and timely repair of failures.
This retrospective longitudinal study investigated the longevity of posterior restorations placed in a single general practice using 2 different composites in filler characteristics and material properties: P-50 APC (3M ESPE) with 70vol.% inorganic filler loading (midfilled) and Herculite XR (Kerr) with 55vol.% filler loading (minifilled). Patient records were used for collecting data. Patients with at least 2 posterior composite restorations placed between 1986 and 1990, and still in the practice for regular check-up visits, were selected. 61 patients (20 male, 41 female, age 31.2-65.1) presenting 362 restorations (121 Class I, 241 Class II) placed using a closed sandwich technique were evaluated by 2 operators using the FDI criteria. Data were analyzed with Fisher's exact test, Kaplan-Meier statistics, and Cox regression analysis (p<0.05). 110 failures were detected. Similar survival rates for both composites were observed considering the full period of observation; better performance for the midfilled was detected considering the last 12 years. There was higher probability of failure in molars and for multi-surface restorations. Both evaluated composites showed good clinical performance over 22 years with 1.5% (midfilled) and 2.2% (minifilled) annual failure rate. Superior longevity for the higher filler loaded composite (midfilled) was observed in the second part of the observation period with constant annual failure rate between 10 years and 20 years, whereas the minifilled material showed an increase in annual failure rate between 10 years and 20 years, suggesting that physical properties of the composite may have some impact on restoration longevity.
Selection criteria: Information pertaining to how the studies were located and selected was very limited. The authors did state that they reviewed the "dental literature predominately from 1990" that reported on clinical studies with a minimum 2-year follow-up and at least an N of 10 at-risk restorations at the last recall. Key study factor: Although a number of important study factors were identified that could potentially impact posterior restoration survival, such as secondary caries, incorrect manipulation of the materials, or material fracture, no specific inclusion or exclusion criteria were identified that were applied across all studies reviewed. Main outcome measure: This review concentrated on the longevity of restorations on posterior teeth subject to occlusal forces. The main outcome measure was survival of the restoration. Where applicable, measures of cause (secondary caries, marginal adaptation, fracture, wear, and so forth) were reported. Main results: There were 42 amalgam studies, 51 direct composite, 5 direct composite with inserts, 7 compomer, 6 glass ionomer, 7 GI tunnel restorations, 6 GI ART restorations, 20 composite inlays and onlays, 36 laboratory-fabricated ceramic inlays and onlays, 20 CAD-CAM ceramic inlays and onlays, and 19 cast gold inlays and onlays. The values reported for annual failure rate were calculated for mean, median, and standard deviation for each material. Mean (SD) annual failure rates for posterior stress-bearing cavities were as follows: 3.0% (1.9%) for amalgam restorations, 2.2% (2.0%) for direct composites, 3.6% (4.2%) for direct composites with inserts, 1.1% (1.2%) for compomer restorations, 7.2% (5.6%) for regular glass ionomer restorations, 7.1% (2.8%) for tunnel glass ionomers, 6.0% (4.6%) for ART glass ionomers, 2.9% (2.6%) for composite inlays, 1.9% (1.8%) for ceramic restorations, 1.7% (1.6%) for CAD/CAM ceramic restorations, and 1.4%(1.4%) for cast gold inlays and onlays. Conclusions: "Longevity of dental restorations is dependent upon many different factors, including materials-, patient- and dentist-related factors." "Principal reasons for failure were secondary caries, fracture, marginal deficiencies, wear, and postoperative sensitivity. We need to learn to distinguish between reasons that cause early failures and those that are responsible for restoration loss after several years of service."