Single-crown restorations in premolar-molar regions: short (<= 6.5) vs longer implants: retrospective cohort study

Ani uae al.
In e na ional Jou nal o Implan Den is y (2022) 8:40
h ps://doi.o g/10.1186/s40729-022-00438-y
RESEARCH
Single-c own es o a ions inp emola –
mola egions: sho (≤ 6.5) s longe implan s:
e ospec i e coho s udy
Edua do Ani ua1,2*† , Mohammad Hamdan Alkh aisa 2 and Asie Eguia1,3†
Abs ac
Pu pose: To compa e he su i al, changes in ma ginal bone le el and p os he ic complica ions a e o sho
(≤ 6.5 mm) and longe implan s (≥ 7.5) suppo ing a single-c own es o a ion in he maxilla y/mandibula p emola
o mola egion.
Me hods: This coho s udy was conduc ed ollowing he STROBE s a emen ecommenda ions o obse a ional
s udies. Clinical ou comes o 88 sho implan s in 78 pa ien s and 88 long implan s in 88 pa ien s we e examined.
All he implan s had been placed by he same su geon and es o ed ollowing he same p os he ic concep ; using a
ansepi helial abu men (in e media e abu men ) and a sc ew e ained es o a ion.
Resul s: All he implan s we e in unc ion a e he ollow-up pe iod since inse ion (median: 31 mon hs; ange 11 o
84 o SiG s median: 35 mon hs; ange: 6–117 o CG; p = 0.139). No s a is ical di e ences (p = 0.342) we e obse ed
ela ed o p os he ic complica ions (sc ew loosening 2/88 s 5/88 CG, ce amic chipping 1/88 s 0/88, empo a y
c own esin chipping 1/88 s 0/88 o SiG and CG, espec i ely) o ela ed o ma ginal bone le el (Mesial o Dis al
MBL ≥ 2 mm in 1/88 implan s o SiG s 3/88 o CG; p = 0.312).
Conclusions: Wi hin he limi a ions o his s udy, no su i al di e ences ha e been obse ed be ween sho implan s
and longe implan s in single-c own es o a ions in pos e io maxilla/mandible.
Keywo ds: Den al implan s, Sho implan s, Ma ginal bone loss, C own- o-implan a io
© The Au ho (s) 2022. Open Access This a icle is licensed unde a C ea i e Commons A ibu ion 4.0 In e na ional License, which
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In oduc ion
Too h loss leads o changes in he in eg i y o he al eo-
la bone and so issues [1, 2]. The healing o ex ac ion
socke s leads o his ological and dimensional changes
in he emaining al eola idge [1–4]. P og essi e a o-
phy o he al eola p ocess begins a his momen bo h
ho izon ally and e ically. Reso p ion o he al eola
idge occu s due o a combina ion o di e en ac o s,
such as loss o he pe iodon al ligamen (and lack o he
ascula iza ion o he bundle bone), loss o unc ion (and
he s imulus on he bone), ac u es in he al eola wall
du ing ex ac ion o he subsequen occu ence o in ec-
ious p ocesses [1–4].
The physiological pos -ex ac ion eso p ion (RRR,
Residual Ridge Reduc ion) [5] can hinde he implan
ehabili a ion o missing ee h. I no only a ec s he
a ailable olume, bu also he densi y o he emaining
bone [5]. These changes could hampe he subsequen
placemen o an implan in an op imal posi ion o a ec
he es he ic esul s. [6]
Clinicians a e o en aced wi h he challenge o ea -
ing pa ien s wi h se e e e ical bone a ophy. Di e en
ea men op ions allow he use o s anda d implan s
in he pos e io egion whe e he ne e canal o he
Open Access
In e na ional Jou nal o
Implan Den is y
†Edua do Ani ua and Asie Eguia con ibu ed equally o he wo k
*Co espondence: edua do@ undacionedua doani ua.o g
1 Clínica Edua do Ani ua, Jose Ma ia Cagigal Kalea, 19, 01007, Vi o ia-Gaz eiz,
Ála a, Spain
Full lis o au ho in o ma ion is a ailable a he end o he a icle
Page 2 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
maxilla y sinus limi he esidual bone heigh , such as
guided bone egene a ion (GBR), maxilla y sinus g a -
ing, inlay o onlay bone g a , dis ac ion os eogenesis,
ne e la e aliza ion o o he s [7, 8]. These echniques
equi e g ea e knowledge and su gical skills on he pa
o he p o essional and po en ially inc ease he compli-
ca ion a e [9–12]. Recen ad ances in implan design
and sizing (sho , ex a-sho implan s) ha e p o ided
new solu ions and al e na i es o ha e allowed op imi-
za ion o exis ing ones [13–15]. In addi ion o acili a e
he p ocedu es, he use o sho implan s educes he isk
o eaching ana omical s uc u es a he ime o d illing,
minimizes he numbe o su ge ies, educes he ime and
cos o ea men , and sa es he need o bone augmen a-
ion. [7, 16–18]
In cases o e ical a ophy, he p os he ic space is
la ge hus inc easing he c own- o-implan a io. Fo -
me ecommenda ions abou he ideal p opo ions seem
ou da ed in sigh o he di e se clinical and biomechani-
cal s udies demons a ing he sa e y and good clinical
pe o mance o sho and ex a-sho implan s [19, 20].
C own- o-implan a ios anging om 0.9 o 2.2 did no
in luence he occu ence o echnical o biological com-
plica ions [21]. Indeed, i has been claimed ha wi hin
he ange o 0.6 o 2.36, he highe he c own- o-implan
a io, he less he pe i-implan ma ginal bone loss (MBL)
[20]. As he leng h o he implan is educed, i has been
sugges ed o inc ease he diame e o enhance he bone–
implan con ac and op imize he dis ibu ion o s ess in
he bone, pa icula ly in cases o low bone densi y. [22]
Sho implan s a e no limi ed o cases o limi ed a ail-
able bone. Cu en ly, sho implan s can be p e e ed o
main ain as much p is ine bone as possible, e en when
s anda d implan s could be housed. [23, 24]
Some au ho s epo ed ha sho implan s could ha e
lowe su i al a es han s anda d implan s [25, 26] bu
ecen sys ema ic e iews ha e shown ha sho implan s
had a be e o equal pe o mance compa ed wi h s and-
a d [27–29] and did no seem o ha e a signi ican in lu-
ence on ma ginal bone loss [30]. Se e al sys ema ic
e iews and me a-analysis ha e been conduc ed o cla i y
he con o e sies on he clinical pe o mance o sho
implan s [25, 31–34] bu hei esul s should be indi idu-
ally in e p e ed wi h cau ion o assess he e en ual p es-
ence o uncon olled con ounding ac o s in he included
s udies [31] (as s udies including bo h splin ed and non-
splin ed es o a ions, implan s placed in bo h g a ed o
p is ine bone, di e en implan designs and su aces o
di e en ypes o es o a i e design).
The e is also ano he con o e sy ega ding he clas-
si ica ion o sho implan s ha could esul in a mis-
in e p e a ion o he esul s. While some au ho s
conside ed sho implan s hose unde 10mm [35, 36],
o he s conside ed a leng h unde 8mm [37] and mo e
ecen ly, o he s unde 6.5mm [38] o 6mm. [39, 40]
Recen e idence om clinical ials has shown he need
o mo e s udies and longe pe iods o ollow-up be o e
he ecommenda ion o sho implan s o suppo single-
c own es o a ions [19, 40]. The objec i e o his s udy
has been he compa ison be ween sho implan s and
longe implan s in e ms o implan su i al, ma ginal
bone emodeling and p os he ic complica ions o single-
c own es o a ions.
Ma e ials andme hods
S udy design
The p esen unicen ic obse a ional e ospec i e s udy
was conduc ed ollowing he STROBE s a emen ecom-
menda ions o obse a ional s udies and in compliance
o he p inciples o he Decla a ion o Helsinki on clinical
esea ch in ol ing human subjec s. Be o e s a ing, he
pe mission o he e hics commi ee was ob ained om
he Basque d ug esea ch commi ee.
Sample size es ima ion
A s udy o a con inuous esponse a iable o ma ched
pai s o s udy subjec s was planned. The sample size was
es ima ed based on p e ious bone loss da a a 12-mon h
ollow-up indica ing ha he di e ence in esponse o
ma ched pai s was no mally dis ibu ed wi h a s anda d
de ia ion o 0.4320 [41]. I he ue di e ence in ma ginal
bone loss a 12mon hs o ma ched pai s was 0.13, 88
pai s o implan s should be necessa y o ejec he null
hypo hesis ha his di e ence in esponse is ze o wi h a
p obabili y (powe ) o 0.8. The p obabili y o ype I e o
associa ed wi h his es o he null hypo hesis was 0.05.
Pa ien s
Da a we e e ospec i ely collec ed om 88 sho
(≤ 6.5 mm; 78 pa ien s) and 88 longe implan s
(≥ 7.5mm; 88 pa ien s) andomly selec ed om a coho
o 16.780 implan s placed om 2012 o 2019 a he same
cen e (Edua do Ani ua Clinic, Vi o ia, Spain). A e
sample size es ima ion, his coho was di ided in wo
g oups (sho implan g oup; SIG and con ol g oup; CG)
and simple andom sampling was conduc ed using he
SPSS so wa e, (SPSS o Windows, Ve sion 15.0. Chi-
cago, SPSS Inc) o selec 88 implan s o m each g oup.
The inclusion c i e ia we e:
– Implan s placed bo h in maxilla o mandible
– Implan s suppo ing a single-c own sc ew- e ained,
es o ed using a ansepi helial (in e media e abu -
men ).
– Pa ien s o e 18yea s
Page 3 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
To add ess sou ces o bias, all pa ien s included in his
s udy had been p e iously ea ed by he same eam,
using he same implan sys em (UnicCa®, BTI Bio ech-
nology, Vi o ia, Spain) and he same su gical and p os-
he ic p o ocols. All he ea men s we e pe o med
ollowing he usual clinical p ac ice o he pa icipa ing
cen e o he inse ion and subsequen loading o sho
and s anda d implan s in he mandible and/o maxilla.
Da a collec ion me hods
The ou comes measu ed we e su i al (p esence o he
implan a he las isi ), MBL and p os he ic ( echnical)
complica ions. The bone le el assessmen was pe o med
e ically measu ing he dis ance om he bone c es
o he i s bone-implan con ac bo h mesially and dis-
ally. Measu emen s o es ima e MBL we e pe o med a
loading ime and a he ime o he las a ailable adio-
g aph using he Sidexis so wa e (Den sply Si ona; Yo k,
US) and he leng h o he implan was used as calib a o .
Among he echnical complica ions sc ew loosening/
b eak and ce amic/ esin chipping we e conside ed.
O he clinically ele an a iables eco ded we e
implan diame e , loca ion, inse ion o que, bone ype,
sex and age, esidual bone heigh , ype o an agonis ee h
and he need o addi ional su gical echniques. Follow-
up ime was calcula ed since implan inse ion (un il las
ecall) and implan loading (un il las ecall).
The c own- o-implan a io was de e mined by di id-
ing he leng h o he c own oge he wi h he ansepi he-
lial (in e media e) abu men by he leng h o he implan .
Residual bone heigh was measu ed om he bone idge
c es o he maxilla y sinus/ne e canal a he implan
posi ion, using he adiog aphy ob ained p e iously o
he su ge y.
In o ma ion abou smoking habi , alcohol in ake, dia-
be es o hype ension was also e ie ed om medical
eco ds. Bone ype quali y [42] was a ed wi h he aid o
compu e so wa e (BTI Scan, BTI Bio echnology, Vi o-
ia, Spain).
S a is ical analysis
A s a is ical analysis was pe o med using specialized
so wa e (SPSS o Windows, Ve sion 15.0. Chicago,
SPSS Inc). Ca ego ical a iables we e exp essed in abso-
lu e and ela i e equencies. Con inuous a iables we e
exp essed as median and ange. Be o e s a is ical analy-
sis, he no mal dis ibu ion o he con inuous a iables
was e alua ed using he Saphi o–Wilk no mali y es .
S a is ical di e ences be ween ca ego ical a iables we e
pe o med by he Chi-squa e es , and s a is ical di e -
ences be ween dicho omous and con inuous ca ego ical
a iables we e pe o med wi h he Mann–Whi ney es .
The e ec o he c own o implan a io on he ma ginal
bone loss was assessed by linea eg ession analysis. The
s a is ical signi icance was se a p < 0.05.
Resul s
The s udy included 176 den al implan s placed in 166
pa ien s ha complied wi h he inclusion/exclusion c i-
e ia. The Sho implan G oup (SiG) was composed by
88 sho implan s (≤ 6.5mm) placed in 78 pa ien s (53
emales; 35 males) and he Con ol G oup (CG) was com-
posed by 88 implan s (≥ 7.5mm) placed in 88 pa ien s
(52 emales; 36 males). Fu he demog aphic da a a e
p esen ed in Table1.
F om he SiG, 71 implan s we e 6.5mm-leng h and
17, 5.5mm-leng h. A ending o hei loca ion, 4 co e-
sponded o Uppe P emola s (UP), 3 o Lowe P emola s
(LP), 52 o Uppe Mola s (UM) and 29 o Lowe Mola s
(LM). Figu es1,2. F om he CG, 69 we e 7.5-leng h, 17
8.5 mm-leng h and 2 we e 10 mm-leng h, and co e-
sponded o 23 UP, 11 LP, 20 UM and 34 LM. Diame e o
he implan s is p esen ed in Fig.3. The diame e o SiG
implan s was highe (p < 0.001).
Residual bone heigh was highe (p < 0.001) in CG
(12.6 s 7.7mm) and c own- o-implan a io was highe
(p < 0.001) in SiG (1.7 s 1.3mm). Figu e4. Con e sely,
he e we e no s a is ical di e ences be ween bo h g oups
ega ding inse ion o que, bone ype o an agonis ype.
Fu he in o ma ion is a ailable in Table2.
A he ime o implan placemen , no di e ences could
be obse ed a ending o he numbe o implan s placed
equic es al (− 0.5 o 0.5 mm), subc es al > 0.5 mm o
sup ac es al < −0.5mm. in mesial, bu a highe p opo -
ion o sho implan s (p ≤ 0.001) we e placed equic es al.
A he ime o loading and las adiog aphy, no di e -
ences in bone le el we e obse ed be ween bo h g oups
in mesial. CG implan s we e mo e subc es al in dis al a
loading ime han SiG implan s (p ≤ 0.001). In addi ion,
du ing he las adiog aphy, a sligh di e ence (p < 0.05)
in dis al bone le el was obse ed in a o o CG implan s.
Mo eo e , he c own o implan a io did no signi ican ly
a ec he ma ginal bone loss (p = 0.781).
Table 1 Demog aphic da a
CG con ol g oup, SiG sho implan g oup
a Mann–Whi ney es
b Chi-squa e es
SiG CG p- alue
Numbe o pa ien s (n = 176) 78 88 NA
Numbe o implan s (n = 186) 88 88 NA
Age (yea s; median ( ange) 56 (20 o 78) 53 (18 o 76) 0.159a
Sex ( emales (males) 52 (36) 53 (35) 0.878b
Smoke s 7 8 0.787b
Page 4 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
Fig. 1 Le : 6.5 leng h implan placed in #3.7 posi ion. Cen e : 2 yea s la e ; single sc ew- e ained c own o e 4 mm. s aigh ansepi helial
(in e media e abu men ). Righ : 6 yea s a e implan placemen . No ma ginal bone loss obse ed a e 6-yea ollow-up
Fig. 2 Le : 8.5 leng h implan placed in #1.4 posi ion. Cen e : 2 yea s la e ; single sc ew- e ained c own o e 2 mm. S aigh ansepi helial
(in e media e abu men ). Righ : 6 yea s a e implan placemen . No ma ginal bone changes a e 6-yea ollow-up
3.30 3.50 3.75 4.00 4.25 4.50 5.00 5.50 6.00 6.25
SiG (≤6.5mm) 23285932 22 41
CG (≥7.5 mm) 319128 6419 16 10
0
5
10
15
20
25
30
35
SiG (≤6.5mm) CG (≥7.5 mm)
Fig. 3 Implan diame e . SiG (sho implan g oup), CG (con ol g oup)
Page 5 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
The ollow-up o den al implan s, since inse ion had
a median o 31 mon hs ( ange 11 o 84) o SiG and
35mon hs o CG ( ange 6–117).
All he implan s om bo h g oup we e in unc ion
a he las ecall (100% su i al) and he numbe o
p os he ic complica ion did no s a is ically di e (3
e en s o SiG s. 6 o CG). A ending o he Heal h
Scale o Den al Implan s [43], Success a e o SIG g oup
was 100% and 98.9% o CG. No s a is ical di e ences
in Ma ginal Bone Loss (MBL) we e obse ed ei he in
Fig. 4 Le : 5.5 mm leng h implan placed in he #2.7 posi ion. Sc ew- e ained single-c own o e a 3 mm ansepi helial (in e media e abu men ).
C own- o-implan a io: 1.84. Righ : 7.5 mm leng h implan placed in he same posi ion (#2.7). Sc ew- e ained single-c own o e a 3 mm
ansepi helial (in e media e abu men ). C own- o-implan a io: 1.80
Table 2 Su gical da a, c own- o-implan a io, and ollow-up da a
a Mann–Whi ney es
b Chi squa e es
G oup p- alue
Expe imen al Con ol
Residual bone heigh (mm; median ( ange)) 7.7 (4.2 o 17.6) 12.6 (7.7 o 20.4) 0.000a
Inse ion o que (Ncm; median ( ange)) 42.5 (5.0 o 70.0) 35.0 (5.0 o 70.0) 0.188a
Bone ype (numbe o implan s)
Type I 4 4 0.234b
Type II 44 49
Type III 33 22
Type IV 7 13
An agonis (numbe o implan s)
Too h 63 66 0.609b
Implan 25 22
C own o implan a io (median ( ange)) 1.7 (1.1 o 2.5) 1.3 (0.9 o 2.1) 0.000a
Immedia e loading (numbe o implan s) 49 49 1.000b
Follow-up since inse ion (mon hs; median ( ange)) 31 (11 o 84) 35 (6 o 117) 0.139a
Follow-up since loading (mon hs; median ( ange)) 27 (4 o 84) 31 (6 o 67) 0.249a
Follow-up o ma ginal bone le el (mon hs; median ( ange)) 24 (3 o 92) 30 (1 o 96) 0.095a

Page 6 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
mesial o dis al be ween bo h g oups a e he ollow-
up pe iod. The e we e no di e ences in he numbe o
implan a eas (mesial/dis al) showing MBL ≥ 2mm (SiG
1/166; 6/166 CG). Addi ional in o ma ion abou he clini-
cal pe o mance is a ailable in Table3.
Discussion
The esul s o he p esen e ospec i e coho s udy
showed no di e ences in su i al, changes in ma ginal
bone le els o p os he ic complica ions be ween SiG and
CG implan s suppo ing a single-c own es o a ion o e
a ansepi helial (in e media e abu men ) in pos e io
maxilla o mandible. These esul s a e in line wi h hose
o he sys ema ic e iew and me a-analysis published
by Tolen ino da Rosa de Souza e al. [7] Sho implan s
in pos e io single c own had simila su i al a es, low
MBL and low p os he ic and su gical complica ions
a e o a 1-yea ollow-up ime. On he con a y Xu
e al. [41] on hei me a-analysis s a ed ha he su i al
a e o sho implan s in he maxilla may be lowe han
ha o long implan s, while in he mandible bo h ype
o implan s showed simila su i al a e. Fu he mo e,
sho implan s ha e been associa ed wi h lowe MBL and
biological complica ions bu highe echnical complica-
ions. I Wo h men ioning ha sho and longe implan
de ini ion was di e en in hese s udies [7, 41]. Mo eo e ,
mos o au ho s selec ed a unique leng h in he SiG and a
unique leng h in he CG ins ead o de ining a limi leng h
be ween bo h g oups. The ype o included a icles (only
RCTs [41] o CCTs and RCTs [7]), he a io o maxilla y/
mandibula implan s, he p opo ion o implan s placed
wi h addi ional echniques, o he ollow-up pe iod could
also explain he di e ences be ween bo h me a-analysis.
Sys ema ic e iews compa ing Sho and S and-
a d implan s including bo h splin ed and non-splin ed
implan s [31, 44, 45] should be in e p e ed wi h cau ion
as he biomechanical pe o mance o splin ed implan s is
subs an ially di e en om non-splin ed ones. In mul i-
ple es o a ions splin ed implan s can dispe se he s ess
on each single implan he eby educing he implan
o e load and he possible incidence o mechanical com-
plica ions [7, 46, 47]. In ela ion o he biomechanical
pe o mance o sho implan s suppo ing single c owns,
simila ou comes ha e been epo ed when he implan is
placed in he mos dis al posi ion in he a ch o be ween
adjacen ee h o o he implan s. [48]
Many a icles ha e been published compa ing he
pe o mance o sho implan s in na i e bone s longe
implan s along wi h sinus g a ing in he maxilla. A
ecen umb ella e iew o me a-analysis om Ve omilla
e al. [28] concluded ha sho implan s showed ewe
biological complica ion a es, educed cos , and an o e -
all simila sa is ac ion a e o he pa ien s.
In he p esen s udy, he c own- o-implan a io o all
he implan s in he CG whe e wi hin he anges ha ha e
been s a ed no o nega i ely in luence he pe o mance
o implan s; om 0.9 o 2.2 [21] o 0.6 o 2.36 [20]. F om
he SiG, only 2/88 implan s sligh ly exceeded his second
Table 3 Resul s. Da a ela ed o implan su i al, MBL (ma ginal bone loss) and p os he ic complica ions
Ma ginal bone (MB) le el ((−): below he mos co onal pa o he implan shoulde ; ( +): abo e he mos co onal pa o he implan shoulde )
a Mann–Whi ney es
b Chi squa e es
G oup p alue
Sho Implan s S anda d
Technical complica ions (numbe o implan s) None 85 82 0.342b
Sc ew loosening 2 5
Resin chipping 1 0
Ce amic chipping 0 1
Mesial MB le el (mm; median ( ange)) Loading 0.7 (− 0.7 o 2.5) 0.7 (− 0.4 o 2.3) 0.173a
Las isi 0.8 (− 1.2 o 2.9) 0.6 (− 3.3 o 2.9) 0.262a
Dis al MB le el (mm; median ( ange)) Loading 0.3 (− 2.5 o 2.3) 0.6 (− 1.3 o 2.3) 0.001a
Las isi 0.4 (− 2.1 o 2.1) 0.5 (− 3.8 o 2.4) 0.018a
Change in MB le el (mm; median ( ange)) Mesial 0 (− 1.5 o 1.3) 0.1 (− 4.0 o 1.4) 0.322a
Dis al 0.1 (− 2.2 o 1.0) 0.1 (− 4.0 o 1.0) 0.758a
Change in MB le el ≥ 2 mm Mesial 0 1 0.316b
Dis al 1 3 0.312b
Change in MB le el ≥ 3 mm Mesial 0 1 0.316b
Dis al 0 1 0.316b
Su i al (numbe o implan s) 88 88 NA
Page 7 o 8
Ani uae al. In e na ional Jou nal o Implan Den is y (2022) 8:40
p e iously published ange and 5/88 he i s one. The
di e ences be ween SiG and CG in he c own- o implan
in he p esen s udy we e lowe han in o he s udies [20,
21] p obably because he leng h o he CG implan s was
lowe .
The use o ansepi helial abu men s in all he implan s
p obably con ibu ed o achie e a low numbe o echni-
cal complica ions in bo h g oups and helped o dissipa e
implan loads hus posi i ely in luencing in he biologi-
cal pe o mance oo [22, 49, 50]. This o al homogenei y
in he ype o p os he ic es o a ion and in he ype o
implan su ace oge he wi h a well-balanced sampling
in ela ion o pa ien s´ sex and age, numbe o smoke s,
bone ype, inse ion o que o ype o an agonis , a e
ele an s eng hs o he p esen s udy. The unicen ic
design o he s udy ensu ed ha all implan s we e placed
and p os he ically ehabili a ed by he same eam, ollow-
ing he same p o ocol. This could ha e helped o educe
bias bu a he same ime he lack o da a om o he
cen e s could be a he same ime conside ed a limi a-
ion o he s udy. O he limi a ions o he s udy we e he
limi ed ollow-up ime o he educed abili y o con ol
con ounding ac o s o he e ospec i e designs. New
long- e m p ospec i e s udies a e ecommended o con-
i m hese esul s.
Conclusions
Wi hin he limi a ions o his s udy, sho (≤ 6.5mm)
and s anda d (≥ 7.5mm) implan s suppo ing a single-
c own es o a ion o e a ansepi helial (in e medi-
a e abu men ) in he pos e io maxilla/mandible show
simila clinical pe o mance (su i al, MBL, p os he ic
complica ions).
Acknowledgemen s
No applicable.
Au ho con ibu ions
All au ho s ha e made subs an ial con ibu ions o he concep ion o design
o he wo k o he acquisi ion, analysis, o in e p e a ion o da a o he
wo k; AND d a ing he wo k o e ising i c i ically o impo an in ellec ual
con en ; AND ha e gi en inal app o al o he e sion o be published; AND
ag ee o be accoun able o all aspec s o he wo k in ensu ing ha ques ions
ela ed o he accu acy o in eg i y o any pa o he wo k a e app op ia ely
in es iga ed and esol ed. All au ho s ead and app o ed he inal manusc ip .
Funding
This esea ch did no ecei e any speci ic g an om unding agencies in he
public, comme cial, o no - o -p o i sec o s.
A ailabili y o da a and ma e ials
The da a se s used and/o analysed du ing he cu en s udy a e a ailable
om he co esponding au ho on easonable eques .
Decla a ions
E hics app o al and consen o pa icipa e
The s udy p o ocol was app o ed by he e hical commi ee o he Uni e si y
Hospi al o A aba (FIBEA-02-ER/22/Ex aco os).
Consen o publica ion
No applicable.
Compe ing in e es s
EA is he Scien i ic Di ec o and he p esiden o BTI Bio echnology Ins i u e,
a den al implan company ha in es iga es in he ields o o al implan ology
and PRGF-Endo e echnology, and he p esiden o Edua do Ani ua Founda-
ion. MHA is a esea che (employee) a BTI Bio echnology Ins i u e. AE is a
esea che a he Edua do Ani ua Founda ion.
Au ho de ails
1 Clínica Edua do Ani ua, Jose Ma ia Cagigal Kalea, 19, 01007, Vi o ia-Gaz eiz,
Ála a, Spain. 2 BTI-Bio echnology Ins i u e, Vi o ia-Gaz eiz, Ála a, Spain. 3 Uni-
e si y o he Basque Coun y UPV/EHU, Leioa, Vizcaya, Spain.
Recei ed: 7 June 2022 Accep ed: 8 Sep embe 2022
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Publishe ’s No e
Sp inge Na u e emains neu al wi h ega d o ju isdic ional claims in pub-
lished maps and ins i u ional a ilia ions.