Immediate restoration implantology is having a greater success
in dentistry since it provides a better aesthetical result
and a better comfort for the patient [1, 2].
Literature concerning this protocol follow up is very poor.
Objective of this work is to compare results from the literature
with those gained from studies of 2014/2015 performed
at the Implantoprostheses Unit in the Department of Oral
and Maxillo Facial Sciences at Sapienza University of Rome.
Main issues of immediate restoration prostheses concern reabsorption
of crestal bone and the following gingival retraction,
leading to exposion of the implant platform and compromising
the final aesthetical result [3-5].
In traditional procedures, at the end of surgical period, a Provisional
Abutment (PA) is screwed on the implant on which a provisional resin crown is cemented. Later on provisional
abutment gets replaced with a definitive one.
In the One Abutment One Time (OAOT) technique, at the end
of surgery, a definitive abutment (DA) is placed directly on the
implant with a provisional resin crown. This way gingival reshiping
that takes place during the following prostheses phase
is eliminated [6-8].
Matherials and Methods
From January 2014 an in vivo study is conducted at the Implantoprostheses
Unit in the Department of Oral and Maxillo
Facial Sciences at Sapienza University of Rome.
Patients were considered eligible for inclusion ifthey fulfilled
the following criteria:
1) at least 18years of age;
2) in need of one or more single implant in the aesthetic
maxillary or mandible area from the left second premolar to the right second premolar, between two natural teeth (or
3) sufficient bone to allow the placementof an implant at least
11.5 mm long with a 3.7 mmdiameter;
4) adequate oral hygiene, i.e. maximumscore for Plaque Index
13 ≤ 2.
Patients were not accepted into the study ifthey met any of
the following exclusion criteria:
1)dehiscence or lack of buccal bone plate after toothextraction;
2) general contraindications to implant surgery;
3) subjected to irradiation in the headand neck area;
4) immunosuppressed or immunocompromisedpatients;
5) treated or under treatmentwith intravenous amino-bisphosphonates;
7) addiction to alcohol or drugs;
8) heavy smoking (≤ 20 cigarettes daily);
9)lack of opposing occluding dentition at the proposedimplant
12 patients were included in the study. Each patient underwent
emathological analysis to evaluate glycemic level, coagulation
factors, blood count and HbsAg, HCV and HIV present.
After analysing Orthopanoramic and TC Cone Beam, plasters
for surgical and prosthetical study were realized.
For each patient Plaque Index (PI) was detected and one
week before surgery patient received their first oral hygiene
sessionduring which they were instructed to use clorexidine
0,2% mouthwash for one minute twice a day starting from 3
days before surgery until one week afterwards. 1 g Amoxicillin
and Clavulanic Acid(Augmentin, Roche, Milan, Italy) Antibiotical
prophylaxis was somministrated every 12 hours for
6 days starting from the day before surgery. Patients allergic to
penicillin were treated with 500 mg of Clarithromycin (Klacid,
Abbott, Rome, Italy)1 hour before surgery and 250 mg twice a
day for one week.
All surgical procedures were performed by the same operator.
If implants did not reach an insertion torque of at least 35
Ncm, patientswere excluded from the study. Before suturing
wound edges transfer was screwed on the implant and a positioning
bicomponent monophase polyvinyl siloxane impression
was taken with pick up technique.
After surgery oral hygiene instructions were providedand patients
were instructed to have a soft diet for 8 days.
A post surgical intraoral radiography using Rinn XCP film
holder (Dentsply Rinn, Elgin, IL, USA)was taken measuring
peri-implant alveolar bone.
Impressions was sent immediately to the dental laboratory
where master casts were made and the titanium abutment was
milled; furthermore on the abutment a methacrylate provisional
resin crown was customed, refined and polished .
Occlusal centric and eccentriccontacts were not permitted on
the provisional restorations, and 200 μm articulating paper
was usedfollowing the guidelines for immediate non-functionalloading . On the same day of surgery a titanium definitive
abutment was screwed on the implant and a frequency
resonance test was performed showing an Implant Stability
Quotient (ISQ) ≥ 60 in every test.
After evaluating Resonance Frequency (RF) a provisional
crown was cemented on each abutment with zinc oxide eugenol-
free cement, TempBond NE (ZNE).
After 8 weeks intraoral radiography using Rinn XCP film
holder (Dentsply Rinn, Elgin, IL, USA) was taken measuring
peri-implant alveolar bone.
PI was also detected and a new oral hygiene session was performed.
2 months after surgery implant restoration was divided into
1. bicomponent monophase polyvinyl siloxane impression of
the definitive abutment
2. Metal structure test
3. rough porcelain test
4. Final Aesthetical test and cementation with zinc oxide eugenol-
free cement, TempBond NE (ZNE).
A 3-months (T1), 6-months (T2), 9-months (T3)and
12-months (T4) follow-up was reported after surgery. An intraoral
radiography using Rinn XCP film holder (Dentsply
Rinn, Elgin, IL, USA) was taken measuring peri-implant alveolar
bone. An oral hygiene session was performed at each
One of the limits of this study was to recreate repeatability on
mesurements of the alveolar bone on periapical radiograph,
due to the difficulty of positioning the RVG sensor in a repeatable
way. The limit was overcame by using adevice called the
Precision Implant X-ray Relator and Locator (PIXRL) developed
by researchers [1<0/a>].
A radiograph positioning device was developed to fit with
commercially available film holders and implant systems.
Thedevice is indexed to the dental implant body and the adjacent
dentition by using an implant placement driver and
polyvinylsiloxane occlusal registration material. By fitting the
device to a conventional film holder, accurate orthogonal radiographscan
monitor changes in bone architecture and prosthetic
A furtherlimit was discrepancy between implant and alveolar
bone radiographic and real measures. Considering this discrepancy,
in orther to avoid any projection error, alveolar bone
measurements were taken following a proportional mathematical
Assessments were made for statistically significantdifferences
in the peri-implant bone levels at eachfollow-up between the
test and the control groupusing the non-parametric Wilcoxon-
Mann-Whitneytest. The mesial and distal measurements on
eachimplant were averaged, and then were averagedat patient
level and then at group level. Statisticalanalysis was performed using the statistical packageStatView (version 5.01.98, SAS Institute
Inc, Cary,NC, USA). Significance was considered at P <
0.05.The intra-observer reliability was assessed usingPearson's
correlation coefficient. The inter-observerreliability was assessed
using the intraclass correlationcoefficient (ICC)20 .
12 patients, between 40 and 67 years of age, with monoedentulism
in aesthetic area starting from the second premolar, wererehabilitated
within 24 hours with definitive abutment and
provisional resin crown.
After measuring level of the crestal bone compared to the implant
length following dates were analyzed (Table 2)
The aim of this study is to evaluate the amount of crestal bone
reabsorption in the prosthetic rehabilitation of monoedentulism
of aesthetic zones using "One abutment one time"
technique. This study compared obtained results with two
sperimental studies from literature where non post-extractive
implants were placed, immediately rehabilitated with a provisional
abutment (PA) in the aesthetic zone (from the left second
premolar to the right second premolar).
In the first study made by Cooper LF et al. reabsorption of
crestal bone was 0,40 mm one year after surgery. In the other
study made by Oyama K.et al.  reabsorption of crestal
bone was 0,28 mm after 6 months and 0,38 mm one year after
Definitive abutment positioning doesn't reduce crestal bone
reabsorption one year after surgery. Different sperimental
studies concerning OAOT technique are shown in literature.
In these studies different clinical situations have been analyzed.
The first main distinction concerns timing of implant
placing. Grandi et al. in their study of 2012  used OAOT
technique in 12 post-extractive implants: crestal bone resorption
was 0,11 mm one year after surgery. The same technique
was used placing 15 implants by Canullo et al. , showing a
mean crestal reabsorption of 0,35 mm after 3 months and 0,33
mm 1,5 years after surgery.
On the other hand this study analyzed crestal bone reabsorption
using OAOT technique on non post extractive implants.
A crestal bone reabsorption of 0,35 mm 6 months after surgery
and 0,35 mm one year after surgery was measured. Comparing
these results with those of Canullo et al.  no significant
difference between the datas was found.Majordifference is
shown between this study and Grandi et al.. One year after
surgery difference between avarage measurments is infact
0,24 mm. OAOT technique would show better results if the
implant is placed right after tooth extraction. From the study
by Canullo et al.  is also shown that OAOT technique used
in post-extractive surgery gives better results than the traditional
method with provisional abutment. As a matter of fact
3 years after surgery a significant difference of 0,21 mm of
crestal bone reabsorption between provisional and definitive
abutment has emerged. Remarkable advantages using OAOT
technique have been shown by rehabilitating two implants
prosthetically attached, even in non-aesthetical areas. Two different
studies concerning this topic exist in literature. In the
first one, made by Degidi et al. , avarage crestal bone reabsorption
was 0,27 and 0,25 respectively 6 months and 1 year
after surgery. These datas concern prosthetic riahabilitation of
one or more elements (not specified) in posterior areas using
non post-extractive one-abutment one-time technique. In the
second study made by Grandi et al. , implants were placed
right after tooth extraction (post-extractive) and crestal bone
reabsorption was 0,065 mm after 6 months and 0,094 mm 1
year after surgery compared to 0,36 mm (6 months) and 0,44
mm (1 year) measured with traditional technique used in
the control group with provisional abutment. Avarage reabsorbed bone in both these cases is lower if compared to our
study measurements, and results have been significatly better
in post-extractive implants. This is probably due to the fact
that implants were often contiguous and were prosthesized together
improving stability and reducing therefore crestal bone
In the following Table 3. datas concerning crestal bone reabsorption
in different studies analyzed in literature are shown,
compared to the datas of this study.
Except for Grandi et al. , for the other studies in literature,
including ours, there is a small and non significant difference
between OAOT and traditional provisional abutment technique
1 year after surgery. This study sought to show that there
is no significant difference between OAOT post-extractive and
non post-extractive technique for what conscerns singol implants
in the aesthetic area 1 year after implant positioning.
Gingival reshaping due to abutment continuous repositioning
 doesn't adversely affect on peri-implant crestal bone
reabsorption whether it's placed in a post-extractive or non
post-extractive site. Advantages of OAOT technique are more
appreciable in case of two contiguous implants prosthetically
attached. This advantage is probably not due to OAOT technique
itself, but to the greater biomechanical stability gained
by implants when attached together.
Within the limits of this study, one abutment-one time technique
used for rehabilitation of single non post-extractive
teeth in the aestethic area, has shown not to significatively affect
peri-implant crestal bone reabsorption compared to traditional
technique. More clinical studies are needed. Furthermore
additional studies are required to evaluate crestal bone
reabsorption with OAOT technique in order to rehabilitate
contiguous implants prosthetically attached.