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Amount of tooth substance gained by crown lengthening:
A SYSTEMATIC REVIEW
Presented by: Dr. Syeda Mahvash Hussain
Resident Operative Dentistry
Aga Khan University Hospital Karachi
Contributors: Drs. Maham Muneeb Lone, Sana Ehsen
Supervised by: Dr. Farhan Raza Khan & Dr. Munawar Rahman
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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: Carranza’s Clinical Periodontology, 9th Edition. Philadelphia: W.B.
Saunders Company, 2002. page 945.
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Chronic inflammation and bleeding
Loss of alveolar bone because of restoration overhang
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Indications
Sub-gingival Fracture Inadequate ferrule Sub-gingival Decay
Badly broken down tooth Excessive gingival
display Tooth wear
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Methods
Gingivectomy/ gingivoplasty
Surgical blade
Electro cautery
Lasers
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Apical repositioning of flap
With osseous reduction
Without osseous reduction
Orthodontic extrusion
Combination
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Review
The 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: 379–385
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Review Question
Amount of tooth substance gained by crown lengthening
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PICO
Patient /population :
Human, mature permanent teeth
Intervention:
Different methods of crown lengthening
Comparison of the intervention:
Comparing the different methods
Outcome(s) :
Amount of tooth structure gained
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Registration of Review
Registration No: CRD42014013266
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Search Strategy
Google scholar
PubMed(NLM)
CINAHL Plus (Ebsco)
“Gingivectomy” or “Gingival cautery” or “Gingivoplasty” or “Gum resection”
AND
“Tooth gain” or “Tooth exposure” or “Crown lengthening” or “ Ferrule”
Literature search
key terms
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Study Selection
Inclusion Criteria:
Exclusion Criteria:
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Studies-Human permanent mature teeth where CLS was done
Outcome-Amount of tooth gained
Primary teeth
Immature permanent teeth
Animal based
In vitro studies
Languages other than English
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First Electronic Search 412
Selection of relevant titles 273
After excluding
No Abstract available
83 Abstracts available
190 Techniques only
different outcome
33 Case reports 92
RCT/Clinical trials n=8
(321 teeth)
Reviews/guidelines 42 Trials not
relevant to objective
10 Finally selected for this review
14
Duplicates Not relevant to topic Not in English Animal based studies
Commentary 1 C.S survey 1 In-vitro 1 Retrospective 2
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Registration No: CRD42014013266
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0
20
40
60
80
100
20 21 27 30 43 43
53
84
Number Of Teeth Assessed
(n = 321)
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Contribution of Data By Weight
6% 7%
9%
9%
13%
13%
17%
26%
N.AYUBIAN n=20
HERRERO n= 21
HAN n= 27
DINIZ n= 30
DEAS n= 43
BRAGGER n= 43
ARORA n= 53
PONTERIERO n= 84
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0
50
100
150
200
250
POSTERIOR TEETH
NOT MENTIONED
73
248
Surgical site
(n =321)
POSTERIOR TEETH
NOT MENTIONED
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0
50
100
150
200
250
300
MENTIONED NOT MENTIONED
30
291
Radiographic Evaluation (n = 321)
MENTIONED
NOT MENTIONED
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0
50
100
150
200
250
300
MANDIBULAR NOT MENTIONED
30
291
Type of Jaw (n = 321)
MANDIBULAR
NOT MENTIONED
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0
50
100
150
200
SUBGINGIVALCARIES SUBGINGIVAL
FRACTURE NOT MENTIONED
80
53
188
Clinical Presentation
(n = 321)
SUBGINGIVALCARIES
SUBGINGIVALFRACTURE
NOT MENTIONED
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Indication For Crown Lengthening
73
27
125
53
43
0 20 40 60 80 100 120 140
Inadequate Ferrule
Sub gingival caries
For proper restorative treatment
Caries and Fracture
Not mentioned
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Follow up of
CLS
Number
of teeth
Minimum
(mm)
Maximum
(mm)
Mean
(mm)
Std.
Deviation
Amount of tooth
structure gained
Initially with APF
and bone reduction
300
1.32
4.00
2.46
1.03
Amount of tooth
structure gained in
3 months with APF
and bone reduction
146
1.60
1.87
1.75
0.13
Amount of tooth
structure gained in
6 months with APF
and bone reduction
196
1.00
1.80
1.49
0.32
Tooth Structure Gained By Crown Lengthening
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The 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
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STRENGTHS
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
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Explore more data through other search engines to expand existing research
More clinical trials are needed to answer the research question