various human and animal study conducted to retrieve the data for the creastal bone loss in both study samples within different intervals of time.

2. A systemic review
JPD July 2016 115;5 Dr. Deeksha Saxena
3rd year

3. Albrektsson et al stated that 0.1 to 0.2 mm of crestal bone
loss after implant loading is a normal phenomenon
crestal bone remodeling
(requirement of long term success of implant)

4. A variety of factors have been associated with crestal
bone loss around dental implants including
 Periodontal biotype,
 Bone density,
 The formation of biological width,
 Implant placement depth,
 Inter-implant distance ,
 Implant Micro-design and Macro-design,
 Occlusal overloading,
 surgical trauma.

5.  The early loss of crestal bone loss facilitates the
stagnation and proliferation of anaerobic bacteria on
exposed implant surfaces,
 If left uncontrolled or untreated may result in the further
loss of perimplant bone.
No one definitive therapeutic strategy is most effective in minimizing Crestal
Bone Loss around implants.

6. But,
 Implant placement (vertical placement = alveolar crest)
 It creates influence on marginal bone resorption, and
placing them in a submerged position,
 Aids in obtaining an ideal emergence profile in esthetic
areas.

7.  Including the use of platform switched implants,
 Using a flapless surgical technique,
 Placing dental implants approx. 2mm below the alveolar
crest(submerged /subcrestal placement).

8. Non- submerged implants Submerged implants
Placing implants – abutment interface in
non-submerged position
More crestal bone loss
Effects on crestal bone remodelling
Placing implant – abutment interface in
submerged position
Mucosa texture
Tonality of the mucosa
Reestablishment of favourable marginal
tissue architecture
Crestal bone remodeling
bone to implant contact ( implant neck
region)
Advantages and Disadvantages

9.  systematic reviews and meta-analyses (PRISMA)
guidelines,
 Databases were searched from 1986 – oct. 2015

10. Specific questions was constructed acc. To PICO i.e.
P Participants: Participants must have undergone
dental implant treatment.
I Types of interventions : the intervention of interest was
the placement of implants using the submerged
technique (ST).
C Control Intervention : Implants were placed using
non-ST.
O Outcome Measures : CBL around implants placed
using ST and non-ST.

11. 32 record identified
through electronic
searches
0 - records identified
through manual
search
13 records selected
after duplicates
removed
13 full text articles
assessed for eligibility
19 excluded after
screening titles and
abstracts
Studies which did not
answer the focused
question -10
Studies in which
platform switched
platform implants were
used – 7
Review articles - 213 articles included in
the systematic review

12.  Original studies,
 Human (clinical ) studies,
 Studies based on animal models (experimental )
 Control group and interventions
 Crestal bone loss around submerged and non-
submerged dental implants,

13. Following databases were electronically searched:-
 Pub-Med / Medline,
 EMBASE,
 Cochrane central register of controlled trials
(CENTRALS),
 Scopus
 Web of knowledge,
 Cumulative index to Nursing and allied Health Literature,
 Google-Scholar

14. Full text of studies judged by title and abstracts to be
relevant were read and evaluated in accordance with the
following eligibility criteria:
 Clinical and experimental studies
 Assessment of periimplant clinical parametres
 Crestal around submerged and nonsubmerged dental
implants.

15.  Studies on Platform-switched implants
 Letter to the editors and case reports
 Case series
 Commentaries
 Historical review
 Articles published in languages other than english were
excluded.

16.  The NewCastle – Ottawa Scale(NOS) was used,
 Grading the methodological quality of each study
assessed in the present systematic review,
 This scale uses a systematic approach based on 3
specific criteria:
 Selection (S)
 Comparability (C)
 Exposure (E)

17. These are subdivided into 9 criteria :
S1, adequate case definition
S2, representativeness of the
cases
S3, selection of control
S4, definition of Control
C1, comparability of cases
C2, controls on the basis of the
analysis
E1, ascertainment of exposure
E2, same method of ascertainment
for cases and controls
E3, nonresponse rate

18.  Each criterion was given a response of
 “YES”,
 “NO” or “cannot tell”
Maximum possible score for each study was given 9.

19.  In total, 13 studies (6 human and 7 animal ),
 All human studies included were prospective,
 4 studies were randomized controlled trials(RCTs)
 No. of participants = 8 – 84 individuals

20.  In this study, split mouth randomized controlled clinical
trial ,
 20 participants
 18 implants (submerged in bone)
 18 implants (non-submerged in bone)

21.  3 studies reported the no. of implants placed
 18- 171 implants
 Crestal(control sites)
 subcrestal (test positions)
 Follow up period 1-5 years
 Crestal bone loss at the test sites ranged from 0.17 to
0.9mm and control sites from 0.02 to 1.4mm

23. Ref. Study
design
RCTs No. of
implants
(n)
No. of
partici-
pants
(n)
Mean
Age
(y)
Study
group
s
Follow
up
Bone
loss
(test –
submer
ged
sites)
Bone
loss
(control
non-
submerg
ed sites)
Cecchi
nato et
al
Prospe
ctive
Yes 324 84 51.6 Group
1
n= NA
Group
2
n= NA
2Y 0.17
mm
0.02
mm
Carrdel
li et al
Split
mouth
No 16 8 >21 n= NA
n=NA
3y 0.25
mm
0.25
mm
Nemli
et al
Split
mouth
Yes 36 20 38.4 n=18
n=18
2y 0.68
mm
0.57
mm
Cecchi
nato et
al
Prospe
ctive
Yes 324 84 NA n=153
n=171
5y 0.17
mm
0.02
mm
Ericsso
n et al
Split
mouth
No 61 11 NA n=NA
n=NA
5y 1.5mm 1.4mmkoh et
al
Prospe
ctive
Yes 20 20 55.5 n=10
n=10
1y 0.9mm 1.4mm

24. The remaining studies included were prospective,
 Performed in dogs
 5- 6 dogs
 Mean age 1-2 years
 Five studies had a split mouth design
 No.of implants placed – 25 to 59 implants,

26. Ref. Study
desig
n
RCTs No. of
implan
ts(n)
No.of
partici
pants
(n)
Mean
age
(y)
Study
groups
Follow
up
Bone
loss
(test –
subme
rged
series)
Bone
loss
(contro
l –
nonsub
merge
d sites)
Calvo-
Guirado
et al
Split
mouth
Yes 48 6 dogs 1 n=24
n=24
4
months
0.91
Mm
1.89
mm
Calvo-
Guirado
et al
Split
mouth
Yes 48 6 dogs 1 n=24
n=24
3
months
0.93
Mm
0.95
Mm
Negri et
al
Split
mouth
Yes 36 6 dogs 1 n=18
n=18
2
Months
2.05
Mm
1.75
mm
Cesarett
i et al
Prosp
ective
No 25 6dogs 1 n=NA
n=NA
2
Months
1.4mm 2.2mm
Herman
n et al
Prosp
ective
YeS 59 5dogs ~2 n=NA
n=NA
6
months
1.68
Mm
1.57
mm
Fiorellini Prosp Yes 38 6 dogs 1 n=18 2 0.67 0.62

27.  Included in this study

28. Human
studies
g
period
t
length
(mm)
t
diamet
er
(mm)
t shape ed t
surface
plant
distanc
e
on
torqu
e
(Ncm)
loading
Cecchi
nato et
al
3 to 6
months
~ 12 3.5 and
4
Tapere
d
Yes MR NA NA Yes
(max. –
man.)
Carrdel
li et al
1.5 to 2
months
NA 3.4,
3.8,4.5
and 5.5
NA Yes MR ~ 3mm NA 8wk
NA
Nemli
et al
3 – 4
months
10-12
3.2 ,4.2 Tapere
d
Yes MR NA 30 2wk
NA
Cecchi
nato et
al
NA NA NA Tapere
d
YES MR NA NA Non
submer
ged –
immedi
ade
loading
submer

29. Ref. Healin
g
period
Implan
t
length
(mm)
Implan
t
diamet
er
(mm)
Implan
t shape
Thread
ed
Implan
t
surface
Interim
plant
distanc
e
Inserti
on
torque
(Ncm)
Implan
t
loadin
g
Ericsso
n et al
NA NA NA NA NA NA NA NA Yes
Man.
Koh et
al
NA NA NA Tapere
d
Yes MR NA NA Not
done
Max.

30.  Overall 3 studies reported the healing period after
implant placement, which ranged from 1.5- 9 months.
 2 studies reported the length of the implants ranged
from 10 – 12 mm
 3 studies which ranged from implant diameter from 3.2
to 5.5mm
 4 studies – tapered implants, 2 studies – not mentioned.

31.  In animal studies, implants were placed in moderately
rough surfaces.
 4 studies- tapered implants
 2 studies – parallel implants

32.  5 of the 6 human studies showed no
significant difference in crestal bone loss
around submerged and non-submerged
implants.
In studies by Nemli et al, Crestal bone Loss was
higher around submerged than non-submerged
implants within the acceptable range of follow up of
2 years.

33.  It was found that poor bone quality (D1 or D4),
 Operator’s skills,
 chronic periodontitis,
 Systemic diseases (uncontrolled diabetes)
 In all human studies, patients were given oral hygiene
maintenance instructions,
 Acc. To this study, oral hygiene plays a significant role in
maintaining crestal bone loss than surgical
interventions.

34.  4 out 7 animal studies showed no significant differences
in submerged and non-submerged dental implants.
 .
But 2 studies reported higher
bone loss and a study by
Negri et al
Follow up 2- 4
months
compared to
human studies
extending to
60 months,
In few animal studies,
showed a difference in
crestal bone loss

35. Follow up period of submerged and non-submerged
techniques if do have affect on bone levels,
 These changes are noted with the post operative
healing period but in long term and marked variedly.
 In animal studies, they are of shorter duration (up to 6
months).
 Further studies are needed to test this hypothesis.

36.  Surgical trauma do effects the crestal bone loss
 Flapless techniques lowers the crestal bone loss than
flap technique.

37.  Within the limits of present review,
 It was concluded that no significant difference exists in
Crestal bone loss around submerged and non-
submerged implants.

38. 1. Linkevicius T, Puisys A, Linkeviciene L, Peculiene V,
Schlee M, Crestal bone stability around implant with
horizontally matching connection after soft tissue
thickening: a prospective clinical trial . Clin Implant Dent
Relat Res 2015: 17 :497-508
2. Javed f, Almas K, Crespi R, Romanos GE, Implant surface
morphology and primary stability: is there a connection?
Implant Dent 2011;20;40-6
3. Romanos GE, Javed F, Delgado-Ruiz RA, Calvo-Guirado
JL. Peri-implant disease: a review of treatment
interventions. Dent Clin North Am 2015;59;157-78

39.  Albrektsson T, Zarb G, Worthington P, Eriksson AR. The long
term efficacy of currently used dental implants: areview and
proposed criteria of success.
Int J Oral Maxillofac Implants 1986;1; 11-25
 Calvo-Guirado JL, lopez-lopez PJ, Mate Sanchez JE,
Gargallo Albiol J, Velasco Ortega E, Delgado Ruiz R. crestal
bone loss related to immediate implants in crestal and
subcrestal position: a pilot study in dogs. Clin Oral Implants
Res 2014; 25;1286-94.