Restorative dentistry paediatric dentistry and orthodontics

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Master Dentistry

Master Dentistry

Volume Two

Restorative Dentistry, Paediatric Dentistry

and Orthodontics

T H I R D E D I T I O N

E d i t e d b y

Peter Heasman BDS, MDS, FDSRCPS, PhD, DRDRCS

Professor of Periodontology

School of Dental Sciences

Newcastle University, UK

Edinburgh London New York Oxford Philadelphia St Louis Sydney Toronto 2013

© 2013 Elsevier Ltd. All rights reserved.

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This book and the individual contributions contained in it are protected under copyright by the

Publisher (other than as may be noted herein).

First edition 2003

Second edition 2008

Third edition 2013

ISBN: 978 0 7020 4597 4

British Library Cataloguing in Publication Data

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Notices

Knowledge and best practice in this field are constantly changing. As new research and

experience broaden our understanding, changes in research methods, professional practices, or

medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in

evaluating and using any information, methods, compounds, or experiments described herein. In

using such information or methods they should be mindful of their own safety and the safety of

others, including parties for whom they have a professional responsibility.

With respect to any drug or pharmaceutical products identified, readers are advised to check

the most current information provided (i) on procedures featured or (ii) by the manufacturer of

each product to be administered, to verify the recommended dose or formula, the method and

duration of administration, and contraindications. It is the responsibility of practitioners, relying

on their own experience and knowledge of their patients, to make diagnoses, to determine

dosages and the best treatment for each individual patient, and to take all appropriate safety

precautions.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors,

assume any liability for any injury and/or damage to persons or property as a matter of products

liability, negligence or otherwise, or from any use or operation of any methods, products,

instructions, or ideas contained in the material herein.

Printed in China

v

Contents

Contributors vi

Preface vii

Using this book viii

1. Periodontology 1

Philip Preshaw and Peter Heasman

2. Endodontics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61

Philip Lumley

3. Conservative dentistry 97

Stewart Barclay and Simon Stone

4. Prosthodontics 127

Craig Barclay

5. Restorative management of dental implants . . . . . . . . . . . . . . . . . 157

Giles McCracken

6. Conscious sedation in dentistry 167

Nigel D. Robb

7. Paediatric dentistry I 193

Richard Welbury and Alison Cairns

8. Paediatric dentistry II 225

Richard Welbury and Alison Cairns

9. Orthodontics I: development, assessment and treatment planning . . . . . 255

Declan Millet

10. Orthodontics II: management of occlusal problems..............293

Declan Millet

11. Orthodontics III: appliances and tooth movement . . . . . . . . . . . . . . 339

Declan Millet

12. Law and ethics 363

Douglas Lovelock

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403

vi

Contributors

Craig Barclay BDS PhD MPhil FDSRCPS DRDRCS MRDRCS

Consultant and Honorary Senior

Lecturer in Restorative Dentistry,

Associate Postgraduate Dental Dean,

Director of Postgraduate Education,

University Dental Hospital of Manchester

Manchester, UK

Stewart Barclay BDS MSc FDSRCPS DRDRCS MRDRCS Ed

Consultant in Restorative Dentistry,

Department of Restorative Dentistry,

Newcastle Dental Hospital,

Newcastle upon Tyne, UK

Alison Cairns BDS MSc MFDSRCSEd MPeadDent FDS RCPS

DipAcPrac FHEA

Senior Clinical University Teacher/Honorary

Consultant in Paediatric Dentistry,

Glasgow Dental School and Hospital,

Royal Hospital for Sick Children,

Glasgow, UK

Peter Heasman BDS MDS FDSRCPS PhD DRDRCS

Professor of Periodontology,

School of Dental Sciences,

Newcastle University,

Newcastle upon Tyne, UK

Douglas Lovelock MSc BDS MDS FDSRCSEng DDRRCR

Emeritus Consultant,

Newcastle upon Tyne Hospitals NHS Trust,

Newcastle upon Tyne, UK

Philip Lumley BDS FDSRCPS MDentSci PhD FDSRCS Eng

FDSRCS Ed

Professor of Endodontology,

Department of Restorative Dentistry,

Birmingham Dental Hospital,

Birmingham, UK

Giles McCracken BDS PhD FDS RCPS

Clinical Senior Lecturer and Honorary

Consultant in Restorative Dentistry,

Department of Restorative Dentistry,

School of Dental Sciences,

Newcastle University,

Newcastle upon Tyne, UK

Declan Millet BDSc DDS FDSRCPS FDSRCSEng

DOrthRCSEEng MOrthRCSEng

Professor of Orthodontics,

Cork University Dental School and Hospital,

Ireland

Philip Preshaw BDS FDSRCS Ed PhD

Professor of Periodontology,

School of Dental Sciences,

Newcastle University,

Newcastle upon Tyne, UK

Nigel D. Robb TD PhD BDS FDSRCSEd FDS(Rest Dent)

FDSRCPS FHEA

Reader/Honorary Consultant in Restorative Dentistry,

School of Oral and Dental Sciences,

University of Bristol,

Bristol, UK

Simon Stone BDS MFDSRCSEd

Clinical Fellow, School of Dental Sciences,

Newcastle University,

Newcastle upon Tyne, UK

Richard Welbury MB BS BDS PhD FDSRCSEng

FDSRCPS FRCPCH

Professor of Paediatric Dentistry,

Department of Paediatric Dentistry,

Glasgow Dental School,

Glasgow, UK

vii

Preface

The philosophy of this textbook remains unchanged

from that of the first edition, where the emphasis

was placed on understanding, learning and self￾assessment so that the reader is able to explore

their own level of knowledge, identify their

strengths and, perhaps more importantly, weak￾nesses or gaps in their knowledge base, which can

then be addressed. Basically, the book comprises

chapters on aspects of restorative dentistry, seda￾tion, paediatric dentistry and orthodontics. There

is also a chapter on law and ethics that has been

updated considerably since the second edition as

a consequence of the considerable changes, devel￾opments and restructuring that have occurred

within the General Dental Council of the United

Kingdom. Changes with respect to registerable

qualifications, development of specialist lists and

the Overseas Registration Examination have also

underpinned significant rewriting of this chapter.

An evaluation of feedback from undergraduate

dental students confirms that a valued part of this

book comprises the sections on assessment. The

popularity of various assessment methods, how￾ever, tends to change on a regular basis and those

assessment methods presented in this textbook are

continuously reviewed to ensure that they remain

in touch with contemporary education philosophy.

Finally, I should like to record my sincerest

thanks to the contributing authors to this book, all

of whom are recognised experts in their respec￾tive specialties and who have worked diligently to

update their chapters for this third edition.

PAH

Newcastle upon Tyne

2012

viii

Using this book

Philosophy of the book

Most students need a textbook that will provide

all the basic facts within a discipline and that also

facilitates understanding of the subject. This text￾book achieves these objectives and also provides

test questions for the student to explore their level

of knowledge. It is also important for students to

achieve a ‘feel for the subject’ and learn communi￾cation skills.

The book is designed to provide basic informa￾tion necessary to pass an undergraduate exami￾nation in restorative, paediatric and orthodontic

dentistry. It also expands on the core curriculum

to allow the motivated student an opportunity to

pursue the subject in greater detail. The informa￾tion is presented in such a way as to aid recall for

examination purposes but also to facilitate under￾standing of the subject. Key facts are highlighted,

and principles of diagnosis and management

emphasised. It is hoped that the book will also be

a satisfactory basis for postgraduate practice and

studies.

Do not think though that this book offers a ‘syl￾labus’. It is impossible to draw boundaries around

the scientific basis and clinical practice of dentistry.

Learning is, therefore, a continuous process carried

out throughout your career. This book includes all

that you must know, most of what you should know

and some of what you might already know.

We assume that you are working towards one or

more examinations, probably in order to qualify.

Our purpose is to show you how to overcome this

barrier. As we feel strongly that learning is not sim￾ply for the purpose of passing examinations, the

book aims to help you to pass but also to develop

useful knowledge and understanding.

This introductory chapter aims to help you:

• to understand how the emphasis on self￾assessment can make learning easier and more

enjoyable

• to use this book to increase your understanding

as well as knowledge

• to plan your learning.

Layout and contents

Each chapter begins with a brief overview of the

content and a number of learning objectives are

listed at the start of each subsection. The main part

of the text in each chapter describes important top￾ics in major subject areas. We have tried to provide

the essential information in a logical order with

explanations and links. In order to help you, we

have used lists to set out frameworks and to make

it easier for you to put facts in a rational sequence.

Tables are used to link quite complex and more

detailed information. Techniques used in various

procedures are listed in boxes.

You have to be sure that you are reaching the

required standards, so the final section of each

chapter is there to help you to check your knowl￾edge and understanding. The self-assessment is in

the form of multiple choice questions, extended

matching items questions, case histories, short

notes, data interpretation, possible viva questions

and picture questions. Questions are designed to

integrate knowledge across different chapters and

to focus on the decisions you will have to take in a

given clinical situation. Detailed answers are given

with reference to relevant sections of the text; the

answers also contain information and explanations

that you will not find elsewhere, so you have to do

the assessments to get the most out of this book.

How to use this book

If you are using this book as part of your examina￾tion preparations, we suggest that your first task

should be to map out on a sheet of paper three

lists dividing the major subjects (corresponding to

the chapter headings) into your strong, reasonable

and weak areas. This will give you a rough outline

of your revision schedule, which you must then fit

in with the time available. Clearly, if your exami￾nations are looming, you will have to be ruthless in

the time allocated to your strong areas. The major

subjects should be further classified into individual

topics. Encouragement to store information and

Using this book

ix

to test your ongoing improvement is by the use of

the self-assessment sections – you must not just

read passively. It is important to keep checking

your current level of knowledge, both strengths and

weaknesses. This should be assessed objectively –

self-rating in the absence of testing can be mislead￾ing. You may consider yourself strong in a particular

area whereas it is more a reflection on how much

you enjoy and are stimulated by the subject. Con￾versely, you may be weaker in a subject than you

would expect simply because the topic does not

appeal to you.

It is a good idea to discuss topics and problems

with colleagues/friends; the areas that you under￾stand least well will soon become apparent when

you try to explain them to someone else.

Effective learning

You may have wondered why an approach to learn￾ing that was so successful in secondary school does

not always work at university. One of the key dif￾ferences between your studies at school and your

current learning task is that you are now given more

responsibility for setting your own learning objec￾tives. While your aims are undoubtedly to pass

examinations, you should also aim to develop learn￾ing skills that will serve you throughout your career.

That means taking full responsibility for self￾directed learning. The earlier you start, the more

likely you are to develop the learning skills you will

need to keep up with changes in clinical practice.

We know that students learn in all sorts of dif￾ferent ways, and differ in their learning patterns at

different stages in a given course. You may intend

to do as little work as you can get away with, or

you may do the least that will guarantee to get you

through the examinations; however, the students

who gain most are usually those who take a deep

and sustained interest in the subject. It will be

worth the effort to start out this way, even if good

intentions flag a little towards the end.

You will also get more out of your course by

participating actively. Handouts, if given, may

help, but they are rarely a satisfactory substitute

for your own lecture notes. Remember that time￾tabled teaching sessions are not the only oppor￾tunities for effective learning. It is safer to regard

lectures, practicals and tutorials as a guide to the

core material that you are expected to master.

Greater depth and breadth to this core knowledge

must be achieved by reference to more detailed

texts. Well-organised departments will provide a

set of learning objectives and a reading list early in

the course. Many lecturers will give more detailed

learning objectives, either in their handouts or

verbally at the start of a lecture. If not, paragraph

headings can be used as a rough guide to the teach￾er’s expectations. An active approach to learning

does not necessarily mean being highly individu￾alistic or overcompetitive. Many students gain a

broader and deeper understanding of the subject by

working in small informal groups. This may be par￾ticularly helpful when it comes to revision.

The final run up to examinations should require

little more than a tying up of loose ends and a fill￾ing of learning gaps. An effective way of doing

this is to work through a steady stream of self￾assessment questions and to keep a daily note of

points that need clearing up. In other words, con￾centrate on what you do not know and strengthen

the links with what you already know. By this

time, the value of pigeonholing factual information

within a framework should be self-evident.

Approaching the examinations

The discipline of learning is closely linked to prepa￾ration for examinations. Many of us opt for a pro￾cess of superficial learning that is directed towards

retention of facts and recall under examination

conditions because full understanding is often not

required. It is much better if you try to acquire a

deeper knowledge and understanding, combin￾ing the necessity of passing examinations with

longer-term needs, particularly with the pros￾pect of continuing professional development after

qualification.

First you need to know how you will be exam￾ined. Does the examination involve clinical assess￾ment such as history taking and clinical examination?

If you are sitting a written examination, what are the

length and types of question? How many must you

answer and how much choice will you have?

Now you have to choose what sources you are

going to use for your learning and revision. Text￾books come in different forms. At one extreme,

there is the large reference book. This type of

book should be avoided at this stage of revision and

only used (if at all) for reference, when answers

to questions cannot be found in smaller books. At

the other end of the spectrum is the condensed

‘lecture note’ format, which often relies heavily

x

Using this book

on lists. Facts of this nature on their own are dif￾ficult to remember if they are not supported by

understanding. In the middle of the range are the

medium-sized textbooks. These are often valuable

irrespective of whether you are approaching final

university examinations or the first part of profes￾sional examinations. Our advice is to choose one

of the several medium-sized books on offer on the

basis of which you find the most readable. The

best approach is to combine your lecture notes,

textbooks (appropriate to the level of study) and

past examination papers as a framework for your

preparation.

Armed with information about the format of

the examinations, a rough syllabus, your own lec￾ture notes and some books that you feel comfort￾able in using, your next step is to map out the

time available for preparation. You must be real￾istic, allow time for breaks and work steadily, not

cramming. If you do attempt to cram, you have

to realise that only a certain amount of informa￾tion can be retained in your short-term memory.

Cramming simply retains facts. If the examination

requires understanding, you will undoubtedly have

problems.

It is often a good idea to begin by outlining the

topics to be covered and then attempting to sum￾marise your knowledge about each in note form.

In this way, your existing knowledge will be acti￾vated and any gaps will become apparent. Self￾assessment also helps to determine the time to be

allocated to each subject for examination prepa￾ration. If you are consistently scoring excellent

marks in a particular subject, it is not very effec￾tive to spend a lot of time trying to achieve the

‘perfect’ mark.

In an essay, it is many times easier to obtain the

first 50% of the marks than the last. You should

also try to decide on the amount of time to assign

to each subject based on the likelihood of it appear￾ing in the examination.

The main types of examination

Multiple choice questions

Most multiple choice questions test recall of infor￾mation. The aim is to gain the maximum marks

from what you can remember. The common form

consists of a stem with several different phrases

that complete the statement. Each statement is to

be considered in isolation from the rest and you

have to decide whether it is ‘True’ or ‘False’. There

is no need for ‘Trues’ and ‘Falses’ to balance out

for statements based on the same stem; they may

all be ‘True’ or all ‘False’. The stem must be read

with great care and, if it is long with several lines

of text or data, you should try and summarise it by

extracting the essential elements. Make sure you

look out for the ‘little’ words in the stem such as

only, rarely, usually, never and always. Negatives

such as not, unusual and unsuccessful often cause

marks to be lost. May occur has entirely different

connotations to characteristic. The latter generally

indicates a feature that is normally observed, the

absence of which would represent an exception to

a general rule, e.g. regular elections are a character￾istic of a democratic society. Regular (if dubious)

elections may occur in a dictatorship but they are

not characteristic.

Remember to check the marking method before

starting. Some still employ a negative system in

which marks are lost for incorrect answers. The

temptation is to adopt a cautious approach answer￾ing a relatively small number of questions. This

can lead to problems, however, as we all make

simple mistakes or even disagree vehemently with

the answer favoured by the examiner! Caution

may lead you to answer too few questions to pass

after the marks have been deducted for incorrect

answers.

Extended matching items (EMIs)

The extended matching items questions are

becoming more popular for dental assessments

and lend themselves well to clinical dental situ￾ations. You are usually presented with an over￾arching theme for the question set and then a list

of 10–15 options from which you have to choose

your answers. There is then a short lead-in state￾ment followed by the stems; a set of questions,

often clinical vignettes, for which you are asked to

select, in your opinion, the one best response from

the aforementioned list. For example, the list may

be causes of dental pain (NUG, reversible pulpi￾tis, irreversible pulpitis and so on), and the clinical

vignettes describe signs and symptoms for which

there is ONE BEST ANSWER to select from the

list. Occasionally, you may be asked to select two

answers from the list or more than one answer

may be appropriate for the one question. As with

any type of assessment, it is crucial that you read

the instructions for the question before attempting

Using this book

xi

to answer so that you know exactly what you are

being asked to do. EMIs are notoriously time￾consuming and difficult to write and are usually

as challenging for the examiners to write as they

are for the candidates to answer! One of the more

common pitfalls when writing these questions is for

the list of potential options to comprise heteroge￾neous, unrelated items, for example five causes of

dental pain, three partial denture components, two

drugs used for sedation and two periodontal diag￾noses. If the vignette is based on dental sedation

then you only have to choose from the two drugs

rather than the other options that are simply irrel￾evant. These questions tend not to be negatively

marked so you would then have a 50–50 chance of

being right should you need to guess!

Essays

Essays are not negatively marked. Relevant facts

will receive marks as will a logical development of

the argument or theme. Conversely, good marks

will not be obtained for an essay that is a set of

unconnected statements. Length matters little

if there is no cohesion. Relevant graphs and dia￾grams should also be included but must be properly

labelled.

Most people are aware of the need to ‘plan’ their

answer yet few do this. Make sure that what you

put in your plan is relevant to the question asked,

as irrelevant material is, at best, a waste of valu￾able time and, at worst, causes the examiner to

doubt your understanding. It is especially impor￾tant in an examination based on essays that time is

managed and all questions are given equal weight,

unless guided otherwise in the instructions. A bril￾liant answer in one essay will not compensate for

not attempting another because of time. Nobody

can get more than 100% (usually 70–80%, tops)

on a single answer! It may even be useful to begin

with the questions about which you feel you have

least to say so that any time left over can be safely

devoted to your areas of strength at the end.

Short notes

Short notes are not negatively marked. The system

is usually for a ‘marking template’ to be devised

that gives a mark(s) for each important fact (also

called criterion marking). Nothing is gained for

style or superfluous information. The aim is to set

out your knowledge in an ordered, concise manner.

The major faults of students are, first, devoting too

much time to a single question thereby neglect￾ing the rest, and, second, not limiting their answer

to the question asked. For example, in a question

about the treatment of periodontal disease, all facts

about periodontal disease should not be listed, only

those relevant to its treatment.

Picture questions

Pattern recognition is the first step in a picture

quiz. This should be coupled with a systematic

approach looking for, and listing, abnormalities. For

example, the general appearance of the facial skele￾ton as well as the local appearance of the individual

bones and any soft tissue shadows can be examined

in any radiograph. Make an attempt to describe

what you see even if you are in doubt. Use any

additional statements or data that accompany the

radiographs as they will give a clue to the answer

required.

Case history questions

A more sophisticated form of examination ques￾tion is an evolving case history with information

being presented sequentially; you are asked to give

a response at each stage. They are constructed so

that a wrong response in the first part of the ques￾tion still means that you can obtain marks from the

subsequent parts. Patient management problems

are designed to test the recall and application of

knowledge through an understanding of the prin￾ciples involved. You should always give answers

unless the instructions indicate the presence of neg￾ative marking.

Viva/oral examination

The viva or oral examination can be a nerve-wrack￾ing experience. You are normally faced with two

examiners (perhaps including an external exam￾iner) who may react with irritation, boredom or

indifference to what you say. You should try and

strike a balance between saying too little and too

much. It is important to try not to go off the topic.

Aim to keep your answers short and to the point.

It is worthwhile pausing for a few seconds to col￾lect your thoughts before launching into an answer.

Do not be afraid to say ‘I don’t know’; most exam￾iners will want to change tack to see what you do

know.

xii

Using this book

In some centres, oral examinations are only

offered to candidates who have either distinguished

themselves or who are in danger of failing. Inter￾views for the two types of candidate vary consider￾ably. In the ‘distinction’ setting, the examiner may

try to discover what the candidate does not know

and may also be looking for evidence of knowledge

of the current literature. A small number of topics

will usually be considered in depth. In the pass/fail

setting, the examiner will try to cover many topics,

often quite superficially. She/he will try to estab￾lish whether the candidate did badly in the written

examination because of ignorance in just a couple

of areas, or whether ignorance is wide ranging.

Remember also that the examiners may have

your written paper in front of them; if you have

done particularly badly in one topic, they may well

take this up in the oral examination. This is not an

attempt to be unpleasant, but a chance for you to

redeem yourself somewhat, so be prepared.

Conclusions

You should amend your framework for using this

book according to your own needs and the exami￾nations you are facing. Whatever approach you

adopt, your aim should be for an understanding of

the principles involved rather than rote learning of

a large number of poorly connected facts.

1

Overview

A healthy or a stable periodontium is an important

prerequisite both for the maintenance of a functional

dentition and to ensure a long-term, successful out￾come of restorative dental treatment. In view of the

high prevalence of gingivitis and chronic periodontitis

in the population, all dental patients should undergo

periodontal screening, although more thorough clini￾cal and radiographic examinations are essential before

a definitive periodontal diagnosis is confirmed and

a treatment plan formulated. These examinations,

together with medical, dental and social histories,

may also reveal predisposing and risk factors that

increase an individual’s susceptibility to, and the sub￾sequent rate of progression of, periodontal disease.

The intensive oral hygiene phase of treatment

and the patient’s compliance with a personalised

plaque-control regimen are of major importance in

stabilising the disease and improving the long-term

prognosis for an affected dentition. Scaling and root

surface instrumentation (RSI) are frequently indi￾cated to disrupt the subgingival biofilm and remove

calculus. Additional adjunctive treatments that may

be indicated are periodontal surgery, guided tissue

regeneration, systemic or locally delivered antimi￾crobials and the management of localised problems

such as furcation defects, mucogingival problems,

periodontal–endodontic lesions and loss of attachment

that has been exacerbated by a traumatic occlusion.

1.1 Healthy periodontium

The diagnostic skills required to identify peri￾odontal diseases, particularly in the early stages,

are based upon a sound knowledge of the clinical

appearance of healthy tissues.

Periodontology

CHAPTER CONTENTS

Overview                       1

1.1 Healthy periodontium 1

1.2 History and examination 3

1.3 Gingivitis                    9

1.4 Periodontal diseases 12

1.5 Microbiology and pathogenesis of

periodontal diseases 16

1.6 Risk factors and predisposing factors 22

1.7 Furcation and periodontal–endodontic

lesions 24

1.8 Gingival problems 30

1.9 Trauma and the periodontium       34

1.10 Syndromes and medical conditions

associated with aggressive periodontitis 37

1.11 Treatment of periodontal disease     39

Self-assessment: questions . . . . . . . . . . . 49

Self-assessment: answers . . . . . . . . . . . .54

Learning objectives

You should:

• know the clinical and radiographic features of

healthy periodontal tissues in adults and in children

• be familiar with the histological structures of the

periodontium.

2

Master Dentistry

Clinical features

The gingiva is pink, firm in texture and extends

from the free gingival margin to the mucogingi￾val line. The interdental papillae are pyramidal in

shape and occupy the interdental spaces beneath

the contact points of the teeth. Gingiva is kera￾tinised and stippling is frequently present. The gin￾giva comprises the free and the attached portions.

The free gingiva is the most coronal band of

unattached tissue demarcated by the free gingival

groove, which can sometimes be detected clinically.

The depth of the gingival sulcus ranges from 0.5 to

3.0mm.

The attached gingiva is firmly bound to under￾lying cementum and alveolar bone and extends

apically from the free gingival groove to the muco￾gingival junction. The width of attached gingiva var￾ies considerably throughout the mouth. It is usually

narrower on the lingual aspect of the mandibular

incisors and labially, adjacent to the canines and

first premolars. In the absence of inflammation, the

width of the attached gingiva increases with age.

The mucogingival line is often indistinct. It

defines the junction between the keratinised,

attached gingiva and the oral mucosa. Oral mucosa

is non-keratinised and, therefore, appears redder

than the adjacent gingiva. The tissues can be dis￾tinguished by staining with Schiller iodine solution;

keratinised gingiva stains orange and non-keratinised

mucosa stains purple–blue. This can be used to

determine clinically the width of keratinised tissue

that remains (e.g. in areas of gingival recession).

Radiographic features

The crest of the interdental alveolar bone is well

defined and lies approximately 0.5–1.5 mm api￾cal to the cementoenamel junction (Fig. 1.1). The

periodontal membrane space, often identifiable on

intraoral radiographs taken using a paralleling tech￾nique, is approximately 0.1–0.2 mm wide. This

accounts for the slight tooth mobility that is some￾times observed when lateral pressure is applied to a

tooth with a healthy periodontium.

Histology

Epithelial components include:

• junctional epithelium cells: non-keratinised and

attached to the tooth surface by a basal lamina

and hemidesmosomes

• sulcular epithelium: non-keratinised and lines

the gingival crevice

• oral epithelium: keratinised and extends from

the free gingival margin to the mucogingival line.

Gingival connective tissue core contains ground

substance, blood vessels and lymphatics, nerves,

fibroblasts and bundles of gingival collagen fibres

(dentogingival, alveologingival, circular and trans￾septal). The combined epithelial and gingival fibre

attachment to the tooth surface is the biologic

width, which is typically 2 mm, not including the

sulcus depth (see Fig. 1.1).

Periodontal connective tissues comprise alveolar

bone, periodontal ligament, principal and oxytalan

fibres, cells, ground substance, nerves, blood vessels

and lymphatics, and cementum.

Periodontal tissues in children

The gingiva in children may appear red and

inflamed. Compared with mature tissue, there is a

thinner epithelium that is less keratinised, greater

vascularity of connective tissues and less variation

in the width of the attached gingiva.

Attached

gingiva

Free

gingiva

Free

gingival

margin

Sulcular

epithelium

Free

gingival

groove

Junctional

epithelium

Biologic

width

Alveolar

bone crest

Keratinised

gingiva

Mucogingival

junction

Oral mucosa

Fig. 1.1 • Diagrammatic representation of the epithe￾lial and connective tissue attachments of the gingiva.