Dental Materials: Foundations and Applications

259 Pages·2016·72.66 MB·English

by  John M. Powers

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Dental 11
Materials
FOUNDATIONS AND APPLICATIONS
JOHN M. POWERS, PhD
Senior Vice President and Senior Editor, The Dental Advisor,
Dental Consultants, Inc.,Ann Arbor, Michigan
Clinical Professor of OralBiomaterials,
Department of RestorativeDentistry and Biomaterials,
Universityof Texas School of Dentistryat Houston,
Houston, Texas
JOHN C. WATAHA, DMD, PhD
Professor of Dentistry, Department of RestorativeDentistry,
School of Dentistry, Universityof Washington,
Seattle,Washington
Contributing Editor
YEN-WEI CHEN, DDS, MSD
Assistant Professor
Department of RestorativeDentistry
School of Dentistry
Universityof Washington
Seattle,Washington
3251RiverportLane
St.Louis,Missouri63043
DENTALMATERIALS:FOUNDATIONSANDAPPLICATIONS,ELEVENTHEDITION
ISBN:978-0-323-31637-8
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Notices
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LibraryofCongressCataloging-in-PublicationData
Names:Powers,JohnM.,1946-,author.|Wataha,JohnC.,author.
Title:Dentalmaterials:foundationsandapplications/JohnM.Powers,JohnC.Wataha.
Description:Eleventhedition.|St.Louis,Missouri:Elsevier,[2017]|
Includesbibliographicalreferencesandindex.
Identifiers:LCCN2015039912|ISBN9780323316378(pbk.:alk.paper)
Subjects:|MESH:DentalMaterials.
Classification:LCCRK652.5|NLMWU190|DDC617.6/95–dc23LCrecordavailableathttp://lccn.loc.gov/2015039912
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P R E F A C E
DentalMaterials:FoundationsandApplicationspresentscon- an introductory section on the nature of materials to give
temporary information about clinical and laboratory dental readersasolidfoundationtounderstandhowdifferentmate-
materials used throughout all dimensions of dental care. rials are, or are not, related.
Key terminology is set in bold type, critical statements are
BACKGROUND italicized, unusual words are defined in brief text boxes, and
quickrevieworsummarystatementsareplacedattheendsof
Nowinitseleventhedition,thistextbookwaseditedforover chaptersormajorsections.Finally,aglossaryoftermsisplaced
30 years until 2003 by Dr. Robert G. Craig. Dr. Craig con- at the end of the textbook. In addition, a companion website
tributed to the education of literally thousands of health created just for this book (http://evolve.elsevier.com/Powers/
professionstudents,usinghisresearchknowledgeandinher- dentalmaterials) contains a variety of resources designed to
ent teaching skills to promote an understanding of dental enhancebotheducationandstudy(seelistingbelow).
materials. This text continues to honor Dr. Craig’s commit-
ment to the dissemination of accurate, current knowledge KEY FEATURES
about dental materials in clinical practice. We continue to
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follow his philosophy of teaching students and clinicians Comprehensive,FocusedCoverage:Fifteenchaptersplusan
the “hows & whys” of the materials they use to treat their introductory section present detailed information about
patients. dental materials used in the dental office and laboratory
and all the materials relevant to day-to-day practice for
dentists,dentalhygienists, anddental assistants.
AUDIENCE (cid:129)
Cutting-Edge Content: The latest materials used in dental
practice are discussed, including those used in esthetic
Thistextbookisintendedforstudentsindental,dentalassist-
dentistry, digital dentistry, and preventive dentistry, and
ing, and dental hygiene programs. It also is an excellent
newadvanced technologies in laboratorypractice.
resource for dental technology programs or programs train- (cid:129)
Art Program: More than 500 full-color illustrations and
ing midlevel providers and will serve as a comprehensive,
photographs liberally supplement the text descriptions
contemporary reference for any practicing dentist or dental
tohelpstudentslearntorecognizethedifferencesamong
professional. Finally, it is a good resource for those in need
the many types of dental materials and thoroughly com-
of a thorough review of dental materials for general or
prehend their appropriate clinical manipulation. Dozens
specialtyboard examinations.
of intraoral photos show how materials are used, step-
by-step, in many cases.
(cid:129)
ORGANIZATION ConsistentPresentation:Eachmaterialpresentationbegins
with a study of the properties and uses of that material
Our goal with Dental Materials: Foundations and Applica- beforemovingontothespecificmanipulationsandappli-
tions, 11th Edition, is to provide a comprehensive source of cations in dentistry, providing a logical framework for
information about dental materials. Following a discussion comparison amongmaterials.
(cid:129)
of the nature of materials, the book provides an overview ReviewQuestions:Eachchapterendswith20to30self-test
about how materials are used to treat or prevent disease questions, the answers to which are provided in the
and trauma. The book then covers important properties of online instructor’s materials, as a student study and
materials, followed by all preventive and direct restorative assessment tool.
(cid:129)
materials used in contemporary dental practice. Later chap- Quick Review Boxes: Each chapter wraps up with a brief
tersfocusonmaterialsusedtofabricateindirectrestorations narrative summarizing the content to recap key concepts
that are critically important to the restoration of a patient’s and help students assess their readiness to progress onto
oralhealthandareimportanttothedentistordentalprofes- the next topic.
(cid:129)
sionalbecauseoftheneedtocommunicateexpectationsaccu- Note Boxes: Interspersed throughout the text, these notes
rately to the patient or laboratorytechnician. highlight key points and important terminology to help
Inthisedition,allchaptershavebeenrevised,butchapters students build the foundational information necessary
on ceramics, implants, impression materials, and polymers for clinical competence.
(cid:129)
havebeencompletelyredonetopresentup-to-dateinforma- SummaryTablesandBoxes:Chapterssummarizeconcepts
tionatanappropriatelevel.Wehaveaddedover60newclin- and procedures within boxes and tables throughout the
ical photos to help students understand the applications of textforeasy-to-readsummariesoftextdiscussionsforref-
materials in dental practice and help teachers convey the erence andstudy.
(cid:129)
same.Wehaveaddedinformationthroughoutabouttherap- VocabularyResources:Boldedupontheirinitialtextmen-
idlyemergingareaof“digitaldentistry.”Wehavealsoadded tion within the chapter, and defined in a back-of-book
iii
iv PREFACE
(cid:129)
glossary to help students master the language of dental Appendices: Several chapters include appendices that set
materials. apart from the text discussion and describe dental mate-
(cid:129)
Learning Objectives: Each chapter begins with a detailed rials (e.g., agar impression material and zinc phosphate
list of student outcomes that serve as study tools and cement) that are less commonly used in modern dental
checkpoints for studentcomprehension. practices.
(cid:129) (cid:129)
Supplemental Readings: Chapters include listings of con- New Ancillary Materials: A color image collection,
temporary texts and journal articles that supply further expanded test bank, and the addition of case studies are
information on the topic at hand to promote evidence- addedtotheinstructormaterials,whereasstudentsbenefit
based practice and provide students with sources of in- fromaccesstoinstant-feedbackassessmentquestionsand
depth study on specific topics. interactiveexercises to reinforceglossary terms.
(cid:129)
ConversionFactors:Theinsidebackcoverincludeslistings
of common metric conversions as a handy reference for
COMPANION WEBSITE
students.
(cid:129)
Evolve Website: A companion site provides resources to
An Evolve website has been created specifically for this text
ease bothinstruction and learning.
and is accessible via http://evolve.elsevier.com/Powers/
dentalmaterials.Assets on this site include thefollowing:
NEW TO THIS EDITION
(cid:129) STUDENT RESOURCES
New Content: Expanded and updated discussions
are included for particularly dynamic areas such as
(cid:129)
Self-Assessment Practice Quizzes
esthetics,CAD/CAMtechnology,cements,ceramics,den-
(cid:129)
Instructional Videos
tal implants, and impressions (including digital impres-
(cid:129)
VocabularyFlashcards
sions) to keep up with changes and advances in dental
materialsand associated technology.
(cid:129)
FullColor:Thistextisinfullcolor,improvingtheclarityof INSTRUCTOR RESOURCES
images and helping students understand complex pro-
(cid:129)
cessesandsequences,anddifferentiateamongthenumer- Test Bank(approximately650 questions)
(cid:129)
oustypes of dental materials,particularly. Case Studies (includingcritical thinking questions)
(cid:129) (cid:129)
NewArtwork:Morethan70newillustrationsandphoto- PowerPoint Presentations
(cid:129)
graphshavebeenadded,includingimagesthatshowmate- Image Collection
(cid:129)
rials being mixed and used, making this often-difficult Answers to Textbook Self-Test Questions
(cid:129)
subject matter easier to grasp. Many intraoral photos are Performance Skills Checklists
included to give the reader a sense of how the materials John M. Powers
are used in sometimes complex sequences. JohnC. Wataha
A C K N O W L E D G M E N T S
WegratefullyacknowledgethedonationsofphotographsforthepreviouseditionsbyDr.Regina
Messer of Georgia Regent’s University and Drs. Kavita Shor, Ricardo Schwedhelm, Richard D.
Tucker, Mats Kronstr€om, J. Martin Anderson, Xavier Lepe, Ariel Raigrodski, James Johnson,
Brandon Seto, Mr. Richard Lee, Sr., and Mr. Andreas Saltzer, all from the University of Wash-
ington School of Dentistry, greatly enhance the learning and understanding of the reader, and
we thank theseindividualsfor contributingthem.
Inaddition,weespeciallythankDr.Yen-WeiChenfromtheUniversityofWashingtonSchool
of Dentistry for his perspective and expertise as we constructed the eleventh edition. We also
acknowledgehisdonationofmanyclinicalphotographs.Asapracticingprosthodontist,teacher
ofpredoctoraldentalandgraduateprosthodonticstudents,andacademician,hisextensiveknowl-
edge about how restorative materials are used in contemporary dental practice has added
immense value to the book for readers and instructors alike. We are grateful for his many
contributions.
v
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Introduction: The Building Blocks of
Restorative Dental Materials
OBJECTIVES
After reading this chapter, the student should be able to: arrangementalongwithexamplesofmaterialsusingeach
1. Describe the importance of the atomic number and the arrangement.
periodic table of the elements. 4. Listthefourmajorclassesofrestorativedentalmaterials
2. Compareandcontrastionic,covalent,andmetallicbonds andexplain howeach is uniqueand howthe atomic
andtheir role inrestorativedental materials. structure of each leadsto its macroscopic and clinical
3. Describe the differences between moleculesand lattices properties.
andcitewhich restorativematerials occur in which
behavethewaytheydo.Beyondatom-to-atombonding,atoms
What makes up the materials in the world around us? What are arranged at a higher level into molecules or crystals that
makes materials different from one another in color, strength, ultimately give dental materialstheir familiar clinical proper-
flexibility,conductivity, or weight? Andwhycan weusesome ties. It is these arrangements of atoms and the nature of the
materialstorestoreteethbutnotothers?Whyaresomematerials bonds among them that allows metals to conduct electricity,
bestsuitedfororalimpressions,othersforfillings,stillothersfor ceramics to have translucence, and elastomers to stretch. We
implants?Theanswerstothesequestionsarebasedontheway willbrieflydiscusstheseideasfurtherinthefollowingsections.
themostbasicunitsofmatterarearrangedandinteract.Inthe
currentpreview,wewillbrieflyexploretheworldofmatterand ALERT
materialsasanintroductiontorestorativedentalmaterials.
Theoralenvironmentisharshanddiverse,andthemate- Atomsarethebasicbuildingblockofalldentalmaterials.The
interactions between atoms are the key difference among
rialsweuseinthatenvironmentmustsurvivemanychallenges.
materials.
Thisenvironmentexperiencesremarkablechangesintemper-
ature,substantialmechanicalforces,adhesionofcommunities
of microorganisms on every exposed surface, and chemical Atoms
attacksfromfoodsandfromthebody,withalltheseoccurring
Everyatomconsistsofanucleusofprotonsandneutronsand
overyearstodecades.Isitanywonder,then,thatthematerials
electronsincloudlikeareasaroundthenucleus(Figure0-1).
neededtofunctioninthisenvironmentarethemselvesdiverse
Thenumbersofprotons(theatomicnumber)determinesthe
andcomplicated?Evenmoreremarkableisthattheroleswe
identity of the atom—whether it is copper, gold, or carbon,
ask these materials to play. We have asked materials to act
etc.Wecallatomswithdifferentnumbersofprotonsdifferent
assurrogatesformissingoralstructuresforthousandsofyears.
elements.Thecomponentsofatomshaveapropertyknown
Buttoday,weincreasinglyaskmaterialstoalsoserveasther-
as charge: protons are positively charged, neutrons have no
apeuticsortoadaptautomaticallytochangingoralconditions.
charge, and electrons are negatively charged. In their native
Theworldofrestorativedentalmaterialsiscomplex,excit-
state,allatomshaveequalnumbersofprotonsandelectrons
ing,andevolving.Inthispreview,wewillintroducematerials
and therefore have no netcharge.
fromthemostbasicperspectiveoftheatomandexplorehow
The number of protons in the nucleus of an atom deter-
atoms interact to form the classes of materials we use every
minesthenumberandarrangementoftheelectronsandelec-
dayinthetreatmentoforaldisease.Intheend,understanding
troncloudsaroundit.Thesecloudsaretechnicallyreferredto
these basic ideas is the key to understanding and predicting
asatomicorbitals;thecomplexshapesandpropertiesofthese
whether our everyday clinical treatments with dental mate-
orbitalsarewellbeyondthefocusofthischapter.Forourpur-
rials will succeed orfail.
poses,itissufficienttounderstandthatthesecloudsofelec-
ATOMS: THE BUILDING BLOCKS trons are the basis by which atoms interact with each other
OF DENTAL MATERIALS and that electron numbers and properties are determined
bythe number of protons.
Thebasicbuildingblockofallrestorativedentalmaterialsisthe The atoms in our universe are arranged into a sophisti-
atom.Atomscombinevariouswaysviabonding;thebonding cated table called the periodic table of the elements
betweenatomsisakeyfeatureofwhatmakesdentalmaterials (Figure0-2);thistableisarrangedinrows(periods)according
vii
viii INTRODUCTION The Building Blocks of Restorative Dental Materials
the periodic table is divided roughly into metals and non-
metals. Metals tend to donate their electrons to other ele-
ments; nonmetals tend to accept electrons. There are
currently about 109 elements in the periodic table, but the
dentalmaterialsweuseeverydayarecomprisedofonlyabout
40orsoofthese.Commonexamplesindentalmaterialsare
oxygen (O), palladium (Pd), tin (Sn), titanium (Ti), alumi-
num(Al),silicon(Si),carbon(C),copper(Cu),andgold(Au).
Bonds between Atoms
Atomsformvarioustypesofbondswithoneanother,anditis
these bonds that, in large part, determine the physical and
chemical properties of dental materials. It is the electrons
FIG0-1 Theatomisthebasicbuildingblockofallrestorative ofatomsandtheconfigurationsofatomicelectroncloudsthat
dentalmaterials.Everyatomconsistsofanucleusofprotons governbondingbetweenatoms.Theelectronsoftheelements
(positively charged) and neutrons (no charge) surrounded by interactinseveralbasicways(Figure0-3).Inthisintroductory
clouds of electrons (negatively charged). In its native state, discussion, we will only touch upon the most basic types of
every atom is electrically neutral, having an equal number of bonds.
positiveandnegativecharges.Thenumberofprotonsdeter-
minestheidentityoftheatomintheperiodictableofelements ALERT
(seeFigure0-2)andisknownastheatomicnumber.Thus,the
atomicnumberdeterminestheelement.Thenumberofelec- Itistheelectronsofatomsandtheconfigurationsofatomic
tronsandtheirconfigurationaroundthenucleuslargelydeter- electroncloudsthatgovernbondingbetweenatomsandulti-
mineshowtheelementbondswithotherelementstoformthe matelytheclinicalbehaviorofrestorativedentalmaterials.
materialsweuseinclinicalpractice.
Ionicbondsareformedwhenanelectronfromoneelement
to the number of protons in the nucleus of the elements. isgivencompletelytoanotherinreturnforformingthebond
Complex chemical rules dictate the number of elements in (Figure 0-3, upper diagram). In dental materials, ionic bonds
each row. Each element has a one- or two-letter symbol; areoftenformedbetweenelectron-donatingelementsandoxy-
thefirstletterisalwayscapitalized.Ifthereisasecondletter, gen. Ionic bonds are common in dental ceramics and are
it is lower case. Remarkably, from this table, we can predict among the strongest type of bond. Ionic bonds also are very
thephysicalandchemicalbehaviorofanelementandgeneral directional, tolerating little movement of the atoms that they
waysofhowitwillinteractwithotherelements.Forexample, bind.Oneuniqueaspectofanionicbondisthatitleavesthe
FIG0-2 Theperiodictableoftheelementsisthetabulationofallelementsintheknownuniverse,currentlynumberingabout109
(notallareshownhere).Therowsofthetable(calledperiods)determinethenatureoftheelectronconfigurationoftheelements;
complexrulesdictatethenumberofelementsineachroworperiod.Eachelementhasatwo-lettersymbol.Forexample,goldis
“Au.”Thepositionofanelementinthetableispredictiveofitselectronconfigurationanditsbonding,chemicalbehavior,andclinical
properties.Forexample,metallicelements(thosethattendtoreleasesomeoftheirelectrons)aregenerallysituatedtowardtheleft
ofthetable,whereasnonmetallicelements(thosethattendtoacceptelectrons)aretowardtheright.Attheextremeright(column
18)sitstheinertelementshelium(He)throughradon(Rn).Thesegasesdonoteitherreleaseoracceptelectronsandareoften
referredtoastheinertgases.Restorativedentalmaterialsarecomprisedofabout40orsoofelements,bothmetalsandnonmetals.