PowerPoint Presentation
Amount of tooth substance gained by crown lengthening:a
systematic reviewPresented by: Dr. Syeda Mahvash HussainResident
Operative Dentistry Aga Khan University Hospital Karachi
Contributors: Drs. Maham Muneeb Lone, Sana Ehsen Supervised by: Dr.
Farhan Raza Khan & Dr. Munawar Rahman
Biologic Width TOOTH
GINGIVA
Takei, HH; Azzi, RR; Han, TJ: Preparation of the Periodontium
for Restorative Dentistry. In Newman, MG; Takei, HH; Carranza, FA;
editors:Carranzas Clinical Periodontology, 9th Edition.
Philadelphia: W.B. Saunders Company, 2002. page 945.
2The biologic width is defined as the dimension of the soft
tissue, which is attached to the portion of the tooth coronal to
the crest of the alveolar bone.It is the distance established by
"thejunctional epitheliumandconnective tissue attachment
The biologic width is patient specific and may vary anywhere
from 0.75-4.3mmbut the mean value is 2mm2
Chronic inflammation and bleeding Loss of alveolar bone because
of restoration overhang 3If a dental restoration violates the
biologic width:chronicpain andinflammationof the gingivaAnd
unpredictable loss ofalveolar bone
This distance is important to consider when fabricatingdental
restorations, because they must respect the natural architecture of
the gingival attachment if harmful consequences are to be avoided.
3
Crown Lengthening4Crown lengthening is the surgical procedure
performed to expose tooth structure by removing gingival tissue,
bone or both to gain adequate height for the purpose of providing a
prosthesisAs we can see in this diagram this is the old gum line b4
CLS and this is the new gum line after CLSAnd it can be appreciated
that there is a significant ATSG after CLS
Why would you need it? 4Indications5There are certain clinical
situations where proper treatment would not be possible without
crown lengthening surgery5Methods Gingivectomy/
gingivoplastySurgical bladeElectro cauteryLasers
6There are several methods by which CLS can be doneGingivectomy
involves removing the gingival tissue to gain crown height with out
raising a flap6Apical repositioning of flapWith osseous
reductionWithout osseous reductionOrthodontic extrusion
Combination
7Apical repositioning involves raising a flap to proceed with
CLSIt could either be with bone reduction or without bone
reduction7ReviewThe most common technique for crown-lengthening
surgery is APF with osseous surgery
Padbury Jr A, Eber R, Wang H-L. Interactions between the gingiva
and the margin of restorations. J Clin Periodontol 2003; 30:
379385
8According to a review by padbury et al
8Review QuestionAmount of tooth substance gained by crown
lengthening
9With these facts at hand and in mind we still wanted to know
which technique provides the best results in terms of amount of
tooth substance gained
This is the reason we decided to conduct a systematic review
which lead us to formulate our review question.
9
PICOPatient /population :Human, mature permanent
teethIntervention:Different methods of crown lengthening Comparison
of the intervention: Comparing the different methodsOutcome(s)
:Amount of tooth structure gained 10Our PICO model was Patient
/population : Human, mature permanent teeth which required CLS
prior to a dental restorationIntervention: Different methods of
crown lengtheningComparison of the intervention: Comparing the
different methods of CLSOutcome : Amount of tooth structure
gained
10Registration of Review
Registration No: CRD4201401326611PROSPERO is an international
database of prospectively registered systematic reviews in health
sciences
Registration with Prospero is imp b/c it increases transparency,
helps safeguard against bias and avoids unplanned duplicationThe
registration of a SR with Prospero is some what similar to
registration of a meta analysis with the Cochrane collaboration
which maintains a log of meta analysis11Search StrategyGoogle
scholarPubMed(NLM)CINAHL Plus (Ebsco)
Gingivectomy or Gingival cautery or Gingivoplasty or Gum
resection ANDTooth gain or Tooth exposure or Crown lengthening or
Ferrule12Literature search key termswas conducted in 3 major Health
Sciences Databases from 1978 till dateAnd the key terms we used to
conduct this search were
12Study SelectionInclusion Criteria:
Exclusion Criteria:
13Studies-Human permanent mature teeth where CLS was
doneOutcome-Amount of tooth gainedPrimary teethImmature permanent
teeth Animal basedIn vitro studiesLanguages other than
EnglishStudies Which had assessed the amount of tooth structure
gained through CLS in human permanent mature teeth
Clinical trials which assessed the amount of tooth gained as an
outcome
13First Electronic Search 412 Selection of relevant titles
273After excluding No Abstract available83Abstracts available
190Techniques only different outcome 33Case reports 92 RCT/Clinical
trials n=8(321 teeth)Reviews/guidelines42 Trials not relevant to
objective10Finally selected for this review14DuplicatesNot relevant
to topicNot in EnglishAnimal based studiesCommentary 1C.S survey
1In-vitro 1Retrospective 2 In collaboration with the librarian we
had 412 articles as the initial electronic search14
Registration No: CRD4201401326615DATA EXTRACTIONThis was the
customized form which we used to extract data from the included
studies for assessment of study quality and evidence synthesis
15
16DATA EXTRACTIONThe compiled data was analyzed using SPSS
version 19.0
16
17In the initial part of the review the unit of analysis was the
individual studyHowever, after selecting the final pool of studies
the unit of analysis shifted to the individual teeth undergoing the
CLS
1718So when we tabulated our results we found that the total
number of teeth assessed in all 8 studies was 321with a minimum of
20 teeth assessed by N. Ayubian and a maximum of 84 teeth assessed
by Ponteriero18Contribution of Data By Weight19N.AYUBIAN
n=20HERRERO n= 21HAN n= 27DINIZ n= 30DEAS n= 43BRAGGER n= 43ARORA
n= 53PONTERIERO n= 84The contribution of individual study to the
overall pool of 321 teeth is as follows1920The surgical site was
mentioned in 2/8 studies which made a total of 73 from the 321
teeth assessed2021And the radiographic evaluation was assessed in
only 1/8 studies which had 30 teeth2122In 7 out of the 8 studies
which is a total of 291 teeth did not mention which jaw maxillary
or mandibular they belonged to 222380 of the 321 teeth assessed in
the 8 studies were affected because of subgingival cariesAnd
another 53 had a fracture going sub-gingivally and the remaining
5/8 studies did not mention the clinical presentation 23Indication
For Crown Lengthening24the most common indication for crown
lengthening was. for proper restorative Tx 24Follow up of CLSNumber
of teeth Minimum(mm) Maximum(mm) Mean (mm)Std. DeviationAmount of
tooth structure gained Initially with APF and bone reduction
3001.324.002.461.03Amount of tooth structure gained in 3 months
with APF and bone reduction 1461.601.871.750.13Amount of tooth
structure gained in 6 months with APF and bone reduction
1961.001.801.490.32Tooth Structure Gained By Crown
Lengthening25When we ran the descriptive statistics for the amount
of tooth structure gained 7/8 studies (300teeth) reported the
initial gain in tooth structure after CLS with a mean of
2.46mmWhile 4/8 studies (146teeth) reported the amount gained after
3months of CLS and the mean was 1.75mm
However only 5/8 studies (196teeth) followed their cases till 6
months after CLS and they reported the mean amount gained to be
1.49mm25
DISCUSSION26AUTHOR TITLE SEARCH STRATEGYSUMMARYHempton T.J et al
2010Contemporary crown lengthening therapy
A REVIEW
Pub med
Google scholarMethods of CLS
Sharma A et al2012Short clinical crowns (SCC) treatment
considerations and techniques A REVIEWPub med Methods for CLSThe
role of restoration margin locationEffects of violation of the
supracrestal gingivae AKUH 2014Amount of tooth substance gained
with crown lengthening
A SYSTEMATIC REVIEWPub med Google scholarCINAHL plus (Ebsco)
Identified the characteristics of the relevant studies:
Most commonly used method for CLSType of studyAmount of tooth
substance gained Year of Publication
27When comparing our study with other researchersWe found that
both hempton et al and sharma et al published a review using search
engines like PubMed and google scholarWhile we used PubMed and
CINAHL plus in our search strategy and our study is a SRIn summary
we looked at Most commonly used method for CLSType of studyAmount
of tooth substance gained Year of Publication
27
conclusions28The number of clinical trials on CLS were limited n
= 8 ( 321 teeth)
The quality of the studies which report data on CL was mostly
inadequate
APF with bone reduction was the most commonly used technique
(7/8 studies) for CLS
The mean amount of tooth structure gained initially was 2.46mm
which decreased to 1.49mm after 6months
29The number of clinical trials on CLS were limited n = 8 ( 321
teeth)
The quality of the studies which report data on CL was mostly
inadequate b/c basic demographics like the surgical site, the type
of jaw (mand or max) radiographic evaluation and clinical
presentation were missing from most of the studies evaluated29
Strengths and Limitations30STRENGTHS The first ever Systematic
review on this topic
LIMITATIONS Only three search engines were used
Studies lacked homogeneity in reporting the outcome
Only experimental studies were included
31Its an ongoing research and we intend to explore data from
other search engines such as the Cochrane library and Google
scholar to make sure that we dont miss any information before
publishing
Review question too focusedOur review question was too specific
therefore we could not include studies which measured variables
like biologic width and gingival recession 31Explore more data
through other search engines to expand existing research
More clinical trials are needed to answer the research
question
32recommendationsExplore more data through other search engines
to expand existing research
More clinical trials are needed to answer the research
question
32Thank you!
33