short oral communications (oral presentations – abstracts 51 to 71)

Short Oral Communications(Oral presentations – Abstracts 51 to 71)

051 Short Oral Communications

Analysis of accuracy of re-positioned abutments invarious implant interfaces

Semper W1, Heberer S1, Mehrhof J2, Schink T3, Nelson K1

1Department of Oral and Maxillofacial Surgery, Clinical Navigation

and Robotics, Berlin, 2Private Office, Zahntechnik Mehrhof GmbH,

Berlin, 3Institute of Biostatistics and Clinical Epidemiology, Berlin

In this in vitro experiment the precision of manually repositioned

abutments in six implant systems with various implant-abutment

interfaces was evaluated.

Material and methods: Of these systems (Straumann ITI, Strau-

mann Bone Level, Astra Tech, Replace Select, Camlog, SteriOss) six

angled (01, 51, 151) implants each were fixated in a prefabricated

metal block. Three persons placed and removed a prefabricated

abutment with anti-rotational features 20 times on each of the six

implants/system using the system-specific screwdriver. A precision

Video check analysis system (precision� 0.7mm and 0.0041) de-

tected the deviation of position of a standardized test body attached

to the abutment and it was measured three-dimensional in a co-

ordinate system. Rotational and vertical changes as well as changes

in angulation were monitored and statistically evaluated using the

non-parametric analysis of variance of repeated measurements.

Results: The tested interfaces showed a deviation ranging from

0.921–4.81 in rotation, one implant system (Camlog) showed a

significant difference in rotational accuracy to all other systems

(P <0.001). Vertical alterations ranged from 1 to 83mm in height.

Statistically significant differences exist between butt-joint and

conical implant-abutment connections. ITI and Astra Tech im-

plants showed no significant difference when compared (P¼ 0.84)

but to all other implant systems (P <0.001) showing deviations less

than 15mm. Canting discrepancies (measurements 0.001–0.311)

were minor distinctive.

Conclusion: The investigation showed that some commercially

available implant-abutment connections are less precise than pro-

moted. The resulting three-dimensional inaccuracy of repositioned

abutments may contribute to fitting accuracy of implant-retained

restorations.


Early loading of SLA implants supporting maxillaryfixed full-arch prosthesis

Lai HC, Zhang ZYDepartment of Oral & Maxillofacial Implantology, Shanghai Ninth

People’s Hospital affiliated to School of Stomatology, College of

Medicine, Shanghai Jiao Tong University, Shanghai

Nowadays large numbers of studies are directed at achieving

quicker osseointegration and shortening healing periods prior to

implant restoration. Maxilla is thought to be a more risky indica-

tion for implant therapy because poor bone quality is common

particularly in posterior maxilla. Therefore, the attempts to apply

early or immediate loading in completely edentulous upper jaws are

relatively less reported.

Objective: This prospective study was aimed to evaluate the

predictability of the early-loaded SLA (sand-blasted, large-grit

and acid-etched) implants supporting maxillary fixed full-arch

prostheses.

Material and methods: 91Straumanns

SLA implants were placed

in 12 edentulous maxillae (6 to 8 implants per patient). The

impressions were taken at 4 weeks post-surgery. The abutments

were tightened and the final fixed prostheses were cemented at 6

weeks post-surgery. Resonance frequency analysis (RFA) and

panoramic radiographs were taken immediately after surgery, at

4 weeks post-surgery, immediately after prostheses attachment

(baseline). And at the yearly follow-ups the radiographs were

also taken.

Results: All the implants were distributed in type 2–4 bone

(16.48%, 67.03% and 16.48% respectively). The survival rate of

implants was 98.90% and the success rate of prostheses was

100% (mean follow-up: 2.5 years). The radiographic results

indicated that the marginal bone level revealed no significant

resorption compared with the baseline. The RFA results re-

vealed ISQ (Implant Stability Quotient) values of 63.44� 4.32,

57.14� 4.25 and 66.43� 3.78 for the 3 time points.

Conclusions: The findings of this study indicated that early

loading of SLA implants supporting maxillary fixed full-arch

prostheses should be predictable.


Histomorphometric comparison of Bio-Oss andStraumann Bone-Ceramic in sinus elevation

Cordaro L1, Chiapasco M2, Vaia E3, Serino G4, Rao W5,Torsello F1

1Eastman Dental Hospital, Roma, 2University of Milan, Milano,3Private Practice, Napoli, 4Private Practice, Roma, 5Private Practice,

Milano

A multicenter, randomized controlled clinical trial has been de-

signed to compare the histological and histomorphometric results of

sinus floor augmentation with Anorganic Bovine Bone (ABB) or

Biphasic Calcium Phosphate (BCP).

The hypotheses to be tested was that the histomorphometrical

appearence of the material was comparable after 6 months of

healing.

Patients could be included in the study if residual alveolar crest

width was > 6 mm and height was > 3 mm and < 8 mm. Forty-

eight maxillary sinuses were treated in 37 patients. According to

852

the randomization list, lateral sinus augmentation was performed

using either ABB (control group; 23 sinuses) or BCP (test group; 25

sinuses). After 180–240 days of healing, implant sites were created

by means of threphine burs. The obtained biopsies were analyzed

for histological and histomorphometric evaluation.

Histology showed close contact between new bone and graft

particles for both groups, with no significant differences in the

amount of mineralized bone (21.6� 10.0% BCP, 19.8� 7.9%

ABB). The bone-to-graft contact was found to be significantly

greater for ABB (48.2� 12.9% ABB, 34.0� 14.0% BCP). Signifi-

cantly less remaining percentage of graft was found in the BCP

group (26.6� 5.2% BCP, 37.7� 8.5% ABB) and significantly

more soft tissue (46.4� 7.7% versus 40.4� 7.3% for ABB).

However the amount of soft tissue for both groups was found not

greater than in the residual alveolar ridge (60.6� 12.8% BCP,

55.2� 15.4% ABB).

The results indicated that both materials are suitable for sinus

floor augmentation. The potential clinical relevance of more soft

tissue and different resorption characteristics of BCP requires

further investigation.


Esthetic outcome of one-piece vs. two-pieceimplants: 3-year prospective study

Younes R1, Nader N2, Makary C1, Abi-Nassif R3, Khalife S3,Jabbour G1

1St-Joseph University, Faculty of Dental Medicine, Department of Oral

Surgery, Beirut, 2Lebanese University, Faculty of Dental Medicine,

Department of Oral Surgery, Beirut, 3St-Joseph University-Faculty of

Medicine, Department of Biostatistics, Beirut

Objectives: Gingival esthetics around natural teeth is based

upon a constant vertical dimension of healthy periodontal soft

tissues, the Biologic Width. When placing endosseous implants,

however, several factors (microgap etc. . .) influence periimplant

soft and crestal hard tissue reactions, which are not well under-

stood as of today. The aim of the present investigation was to

evaluate the marginal bone level after 3 year of follow-up of 1-

piece vs. 2-piece implants after immediate provisional restora-

tion fabrication.

Methods: 52 Patients included in a split-mouth design prospec-

tive study received either 1-piece or 2-piece (one abutment, one

time) Zimmer dental implants (Carlsbad, USA) in cases of

symmetrical missing lateral incisor cases that were immedi-

ately restored and placed into function as part of a 3-year

multicenter investigation. Periapical X-rays at time 0, 2, 6, 12

months and 3 years enabled us to evaluate the vertical bone loss

based on the well-known implant length. The Student t test and

Pearson correlation were used to estimate the influence of

separate parameters on marginal bone.

Results: 2 implants, one in each group were lost, resulting in a

cumulative survival rate of 98.07% after 3 years. The average

marginal bone loss level at the 3-year follow-up was 0.67 mm

(SD¼ 0.36) in 1-piece vs. 1.2 mm (SD¼ 0.69) in 2-piece implants.

Shallow implant positioning resulted in less gingival and mar-

ginal bone remodeling compared to deep implant positioning.

Conclusion: Stable marginal bone level support the hypothesis

that the 1-piece implant had further capacity to preserve both

hard and soft tissue in order to achieve long-lasting esthetics.


Corrosion in implant retained cast titanium andcobalt-chrome frameworks

Hjalmarsson L1, Wennerberg A2, Smedberg JI3

1Department of Prosthetic Dentistry, Public Dental Health Service,

The Malar Hospital, Eskilstuna, 2Department of Prosthodontics, Faculty

of Odontology, Malmo University, Malmo, 3Department of Prosthetic

Dentistry, Public Dental Health Service, St Erik Hospital, Stockholm

Objectives: To examine corrosion of implants and titanium or

cobalt-chrome frameworks before and after exposure to artificial

saliva.

Experimental methods: Four full-arch implant frameworks were

fabricated according to the Cresco Ti Precision methods

(Astra

Tech AB, Sweden), two in CP titanium and two in a cobalt-

chrome alloy. Each framework was vertically cut in five sec-

tions. The three central sections were used. Their contact

surfaces to the implants and the corresponding surfaces of six

Branemark Systems

implants (Nobel Biocare AB, Sweden) were

examined with optical interferometry before and after exposure

to artificial saliva. Leakages of titanium, chrome and cobalt

were observed. Before saliva exposure, three implants were

screw retained to titanium sections (TiI) and three to cobalt-

chrome sections (CoCrI). The remaining titanium (Ti) and

cobalt-chrome (CoCr) sections were unconnected. The signifi-

cance level was set at 5%.

Results: Before saliva exposure, significant rougher surfaces

were revealed in the Ti-group compared to all other groups

and in the CoCr-group compared to the implant groups. After-

wards, significant decreased differences were found between the

Ti-group and the TiI-group. Within two groups, Ti and TiI,

significant rougher surfaces were present after saliva exposure

than before. Significant higher leakages of cobalt were found in

the CoCrI-group compared to ions leakages from any other

group except the CoCr-group.

Conclusions: The Cresco frameworks, regardless of material, had

rougher contact surfaces than the implants. Saliva exposure made

titanium frameworks and implants which had been connected to

titanium frameworks rougher. Significant cobalt leakage was

detected. These findings indicate active corrosion processes.


Method and results in harvesting mandibular boneblock grafts

Khoury F, Hanser TClinic Schloss Schellenstein, Olsberg

Since 25 years mandibular bone block grafts are harvested using the

MicroSaw (Dentsply Friadent, Mannheim, Germany). With the

MicroSaw handpiece two vertical cuts are made in the retromolar

853

region which are connected basilary with the contra-angled hand-

piece and next to the crest with holes made with the drill.

Connecting the holes with a chisel the bone block can be luxated

to the buccal.

Between 1982 and 2006 a total of 5964 autogenous bone block

grafts were obtained using the MicroSaw from the retromolar area

(n¼ 4831/75%), symphysis region (n¼716/12%) and edentulous

ridge segments (n¼ 417/8%). In addition to clinical palpation of the

donor site a panoramic radiograph was used to map the individual

anatomy before the bone block preparation. Lateral cephalometric

radiographs were used additionally for donor site assessment when

grafts were harvested from the symphysis region. Volumetric

measurements of the grafts were made and parameters such as lip

and soft tissue sensibility, vitality of teeth, wound healing and

clinical complications inspected.

Volumetric measurements of the grafts showed that the average

graft volume harvested from the chin was 2.7 cm3 as compared to

2.0 cm3 from the retromolar area and 1.6 cm3 from edentulous ridge

sections of the mandible. The intra- and postoperative complication

rate of harvesting grafts from the retromolar area was 0.5%, lesions

of the inferior alveolar nerve did not occur. No complications

occurred when bone was obtained from edentulous ridge segments

of the mandible. The complication rate in the chin region was

9.5%, mainly anaesthesia and paresthesia of the lower anterior

teeth for more than 6 months after surgery.

The data and experience described of this 25-year analysis

indicates that the described diagnostic protocol and surgical proce-

dure allowed efficient and safe bone block harvesting from intraoral

mandibular sites. An injury of the mandibular nerve seems to be

unlikely when the osteotomy is within the retromolar area. If big

bone blocks should be harvested including the area of the ramus, the

distal osteotomy should be made only with half of the cutting depth

of the diamond disc because the position of the nerve might be more

superficial.


Immediate function using computer guided implantsin Pterygo-maxillary region

Polizzi G1, Cantoni T2

1Private praxis BSC, Verona, 2Private praxis BSC, Verona

Objectives: Purpose of the study.To evaluate the clinical outcome of computer guided Pterygoid

implants, immediately loaded, compared to the conventional ap-

proach to the pterygoid area.

Material and methods: 51 patients (31 females, 20 males) mean

age 59 (34–77), with atrophic maxilla, were selected for pter-

ygoid implants and consecutively included.

40 patients (group A), totally and partially edentulous, were

treated using 239 implants (66 Pterygoid) immediately loaded

after guided surgery (Flapless technique using NobelguideTM

protocol).

11 patients (group B), reference group, were treated with conven-

tional (flap, trap door technique and Sinus walls control) staging

approach, using 61 implants (16 Pterygoid). VAS was used to

evaluate patient’s opinion.

Results: The follow-up period was 12–48 months. In the group

A, one implant in the pterygoid region could not reach primary

stability. 3 other anterior implants failed. No implant failure

was recorded for the reference group B. The difference regarding

implant survival rate (98.75%–100%) of the two groups was not

significant. All the implants, in the pterygo-maxillary region

(n¼ 81), except one reached primary stability and were stable at

follow-up.

Conclusion: Implants guided, after software based planning, and

immediately loaded can predictably integrate in the pterygoid

region. The less invasive procedure seems safe but require

perfect knowledge of the anatomy and accurate planning. The

patient’s opinion, regarding post-operative pain, comfort and

function, was in favor of the flapless guided approach and

immediate loading.


Marginal bone resorption: comparison betweendifferent rehabilitation techniques

Nowakowska J, Basso M, Del Fabbro M, Francetti LUniversity of Milan, Galeazzi Institute, Section of Odontology, Milan

Aim: This prospective study evaluated marginal bone resorp-

tion between a computer guided flapless technique (Nobel

Guides

, Nobel Biocare) and two traditional protocols for implant

positioning in fully or partially edetulous.

Material and methods: A total of 229 implants (Nobel Speedys

,

MK-IVs

or Replaces

Select, Nobel Biocare) were placed in 76

fully or partially edentulous patients. They were rehabilitated

by full arch fixed prostheses, single crowns or bridges. All the

implants selected for this study had same implant surface

(TiUnites

, Nobel Biocare). Bone level evaluation was assessed

by image software (Image Tools

3.0, UTHSCSA), analyzing

intraoral radiographs obtained through individual positioning

devices.

Number ofPATIENTSIMPLANTS

Rehabilitationtype

Loadingtime

Follow-up CumulativeSuccessRate %

21/84 All-on-4s

Immediate 24 months 100%12/48 All-on-4

s

computerguided

Immediate 24 months 100%

43/97 Single crowns,bridges

Delayed 24 months 95.84%

Results: For All-on-4 cases, marginal bone resorption averaged

1.62� 0.4 mm at 24 month evaluation for traditional protocol,

and 1.1� 0.33 mm for computer guided technique. In cases

treated with delayed loading protocol, single crowns or bridges

rehabilitations, bone resorption was 1.43� 0.3 mm at 24

months. Non significant statistical data were collected about

relation between bone resorption and implant length, diameter,

position and type of rehabilitation.

Conclusions: This study indicated that computer guided tech-

nique may result in lower bone resorption (p < 0.05) around

854

dental implants in respect to traditional protocols. It seems to

depend on technique but moreover on diagnosis, pre-surgical

preparation, and careful protocols application in computer plan-

ning and surgical procedures.


Clinical outcome of tapered implants placed withhigh insertion torques (up to 176 Ncm)

Khayat P1, Arnal H2, Tourbah B2, Sennerby L3

1University of Paris VII, Paris, 2University of Paris V, Paris, 3Institute

for Surgical Sciences, Goteburg University, Goteburg

Objectives: The aim of this study was to report on the

clinical outcome of implants placed with a maximum insertion

torque (MIT) equal or greater than 70 Ncm and evaluate bone

levels around these implants at time of loading and one year

after.

Material and methods: This study was designed as a prospective

study. MIT was recorded with an electronic torque measuring

device (Tohnichi) on 66 tapered implants (4.7 mm Screw-Vent,

Zimmer Dental). Torques below 30 Ncm could not be measured

by this instrument. Nine implants presented MIT between 30

and 50 Ncm (control group) and 42 implants MIT equal or

greater than 70 Ncm (experimental group). Fifteen implants

with MIT between 50 and 70 Ncm were not included in the

study. Marginal bone levels were recorded at time of loading and

one year after.

Results: Mean MIT was 37.1 Ncm (control group) and

110.4 Ncm (range 70.8 to 176 Ncm, experimental group). All

implants were clinically stable after one year of loading. Mean

marginal bone resorption was 1.03 mm (SD¼ 0.44) for the con-

trol group (low torque) and 0.72 mm (SD¼ 0.56) for the experi-

mental group (high torque) at time of loading. It was 1.09

(SD¼ 0.62) and 1.24 mm (SD¼ 0.75) respectively after one

year. There was no difference between low and high torque

groups (Wilcoxon Rank Sum test, p > 0.05) at any time. More-

over, there was no correlation between insertion torque and

marginal bone resorption when grouping all measurements

(Spearman correlation test, p > 0.05).

Conclusions: The use of high insertion torques (up to 176 Ncm)

did not prevent osseointegration. Marginal bone levels in the

low and high torque groups were similar both at time of loading

and one year after.


Biological & prosthetic complications with fixedprosthodontic reconstructions on implants after 2–15years of function

Gisakis IG, Zabaras D, Bouboulis, SpanosDepartment Dental Implants & Bone Regeneration, HYGEIA

Hospital, Athens

Aim: The aim of this retrospective study was to evaluate the

frequency of biological and prosthetic complications with fixed

prosthodontic reconstructions on Straumann dental implants

(Institute Straumann AG, Basel, Switzerland) after 2 to 15 years

of function.

Material and methods: A total of 932 patients (429 male, 503

female) participated in the study, in which 3043 implants were

inserted. The diameter of the implants was: a) 3.3 mm, 518

implants (17.02%), b) 4.1 mm, 2282 implants (74.99%), c)

4.8 mm, 243 implants (7.98%). The length of the implants

was: a) 8 mm, 426 implants (13.99%), b) 10 mm, 1399 implants

(45.97%), c) 12 mm, 1218 implants (40.03%). A total of 1063

fixed prosthetic restorations were placed: 143 (13.45%) full-arch

dentures, 506 (47.61%) partial dentures and 414 (38.95%) single

crown prostheses. At the time the restorations were mounted,

all implants showed clinical signs of stable osseointegration. All

patients underwent detailed clinical [plaque index (PI), bleeding

index (BI), probing depth (PD), probing attachment level (PAL)]

and radiographic [crestal bone level: mesial site, distal site]

examination every 6–12 months, or earlier in cases of bruxism,

heavy smoking, impaired general health and diagnosed peri-

implantitis.

Results: The main results of the study were:

A] Biological complications: 1) Periimplantitis was revealed in

638 implants (20.97%) (p¼0.846). Out of them: 55 (1.81%) in

patients with good oral hygiene, 174 (5.72%) in patients with

moderate oral hygiene and 409 (13.44%) in patients with poor

oral hygiene (p¼ 0.043). Most cases (383, 60.03%) revealed in the

time interval of 6–10 years of function. In total, 259 implants

(8.51%) were lost due to periimplantitis, while the majority of them

(156, 5.13%) in patients with poor oral hygiene (p¼ 0.067).

2) Regarding peri-implant parameters (means): PI 0.58 (0.53), BI

0.42 (0.44), PD 3.19 mm (� 0.98) and PAL 3.5 mm (� 1.19). 3)

Marginal bone loss around implants ranged from 1.14 mm (� 0.75)

at mesial sites to 1.19 mm (� 0.80) at distal sites (p¼ 0.056).

Factors associated with bone loss, except poor oral hygiene

(82.34% in patients of this group, p < 0.05), were bruxism

(43.34% in this group, p¼ 0.573) and heavy smoking ( > 35 cigar-

ettes per day) (21.13% in this group, p¼ 0.813).

B] Prosthetic complications: 1) Regarding implants and abut-

ments (in total of 2784 implants, during the study period): in 112

cases (4.02%) untightening of abutment screw in single crown

restorations, in 65 cases (2.33%) fracture of abutment screw, in 35

cases (1.26%) fracture of the abutment and in 68 cases (2.44%)

implant fracture (p > 0.05). 2) Regarding prosthetic restorations: in

16 cases (1.52%) fracture of metal framework, in 7 cases (0.67%)

porcelain fracture and in 42 cases (4.01%) loss of cementation

(p > 0.05). The prevalence of fractures was higher in patients with

bruxism (p¼ 0.067), and concerned in the majority of cases implant

of 3.3 mm in diameter (p < 0.001). Most of the complications

revealed between the 2nd and 5th year of function (173 cases,

50.14%) (p < 0.05).

Conclusions: a) the mean implant survival rate was 89.25%,

b) poor oral hygiene was the major risk factor of periimplantitis

and implant loss, c) bruxism was an important risk factor for

marginal bone loss and fractures.

855


Esthetic outcome of ceramometal and all-ceramicsingle-tooth implant restorations: a randomizedcontrolled trial

Gruetter L1, Gallucci G2, Belser U3

1University of Geneva, Department of Prosthodontics, Geneva,2Department of Restorative Dentistry and Biomaterials Science,

Harvard School of Dental Medicine, Boston, 3University of Geneva,

Head of Department of Prosthodontics, Geneva

Objective: This study compared the objective/subjective

esthetic outcome of screw-retained ceramo-metal (control) and

all-ceramic (test) single-tooth implant restorations in the ante-

rior maxilla.

Material and methods: 22 patients were randomly allocated to

one of the two groups, 17 patients completed the first year

evaluation.

These objective measurements were taken at baseline, crown

insertion (CI) and 1-year:

Intraoral digital photograph, height of mesial and distal papilla,

length of adjacent teeth and length of the restoration (excepted

baseline), then DIM value (excepted baseline) and periapical radio-

graph to assess DIB values.

Subjective measurements: Visual Analogue Scale (VAS) of

patient’s overall treatment satisfaction and expert clinicians’

judgements on overall treatment and esthetic integration

Results: Statistically analyzed as: ‘‘between groups’’ (control vs.

test) and ‘‘within group’’. At baseline, the mean mesial and

distal papilla length at implant sites was 2.84 mm and 2.21 mm,

respectively. When comparing papilla height at CI (3.19 mm and

2.64 mm) and at one year (3.34 mm and 3.14 mm), a statistically

significant increase was observed. A statistically significant

increase in mean DIM values was observed between baseline

and CI, more pronounced at mesial and distal sites. The same

trend was visible at buccal sites, but less pronounced. Radio-

graphic analysis revealed normal bone remodeling. These objec-

tive parameters were similar for test and control groups. VAS

showed a high degree of satisfaction with the esthetic results,

regardless of the type of restoration.

Conclusion This RCT study on anterior single-tooth implant

restorations revealed excellent overall esthetic results. No statisti-

cally significant differences were observed between the two restora-

tion types investigated.


Bone apposition around two different SLA implantsurfaces at defect sites

Zhuang LF, Zhang ZY, Lai HCDepartment of Oral & Maxillofacial Implantology, Shanghai Ninth

People’s Hospital affiliated to School of Stomatology, College of

Medicine, Shanghai Jiao Tong University, Shanghai

Objective: The study was designed to evaluate bone apposition

around SLA (sandblasted and acid-etched) implants compared

with modified SLA (modSLA) ones at sites with different sizes of

circumferential gaps.

Material and methods: All mandibular premolars and first

molars of 6 Beagle dogs were extracted bilaterally. After a

healing period of 3 months, three 10 mm-long implants were

inserted in each side of the mandible. One implant was inserted

with a 1 mm and one with a 1.35 mm gap between the implants

and bone around the coronal 5 mm of the implants. The third

implant was inserted without a gap as a control. The dogs were

sacrificed respectively at week 2, 4 and 8 after implant place-

ment for histologic and histomorphometric analyses. Resonance

frequency analysis (RFA) was conducted immediately postpla-

cement and before euthanization.

Results: The histomorphometric results showed similar pattern

of bone apposition for the two surfaces. At 2 and 4 weeks of

healing, the percentage of newly formed bone-to-implant con-

tact (BIC) was significantly higher for modSLA in all the 3 sites

(p < 0.05). At 8 weeks of healing, this difference was not sig-

nificant (p > 0.05). RFA results showed significant difference

between the two implant surfaces only at week 2 and 4

(p < 0.05) while no significant difference was found for week 8

(p > 0.05).

Conclusions: Significantly more bone apposition was found for

the modSLA surface than for the SLA surface at 2 weeks of

healing, indicating that the modSLA surface may possess an

advantage when inserted in extraction sockets or compromised

sites.

This project was supported by ITI Foundation.


Immediate rehabilitation of the edentulous mandiblewith a definitive prosthesis supported by an intra-oralwelded titanium bar

Degidi M1, Nardi D1, Piattelli A2

1Private Practice, Bologna, 2University of Chieti-Pescara, Chieti

Purpose: The aim of this prospective study was to evaluate the

suitability of intra-oral welding of implant frameworks to allow

placement of final restoration on the same day of surgery.

Material and methods: Forty patients with edentulous mandible

were planned to be treated with a fixed restoration supported by

an intra-oral welded titanium bar. Definitive abutments were to

be connected to the implants and then welded to a titanium bar

using an intra-oral welding unit. This framework was to be used

as a support for the final restoration, which was to be placed on

the same day as implant placement. Mean marginal bone loss

and radiographically detectable alteration of the welded frame-

work were to be assessed using periapical radiographs immedi-

ately after surgery, and at 6, 12 and 24 month follow-up

examinations.

Results: 20 males and 20 females, with a mean age of 47.8 years

old (SD¼ 13.9; n¼ 40), were consecutively treated with 160

immediately-loaded implants. All implants osseointegrated.

No fracture or radiographically detectable alteration of the

welded framework were present. All implants were clinically

stable at the 24 month follow-up. Mean marginal bone loss,

assessed using 640 periapical radiographs, was 0.59 mm

(SD¼ 0.12; n¼ 160) at 6 months, 0.21 mm (SD¼0.051; n¼160)

856

at 12 months and 0.11 mm (SD¼ 0.036; n¼160) at 24 months.

The accumulated mean marginal bone loss was 0.91 mm

(SD¼ 0.21; n¼160).

Conclusions: It is possible on the same day as surgery to

successfully rehabilitate the edentulous mandible with a fixed,

permanent prosthesis supported by an intra-oral welded

titanium framework.


Lateral ridge augmentation using different bonesubstitutes biocoated with rhGDF-5/ rhBMP-2

Schwarz F1, Sahm N1, Ferrari D1, Rothamel D1, Sager M2,Becker J1

1Department of Oral Surgery, Heinrich Heine University, Dusseldorf,2Animal Research Institute, Heinrich Heine University, Dusseldorf

Objectives: The aim of the present study was to immunohisto-

chemically evaluate lateral ridge augmentation using a particu-

lated (BOG) or block (BOB) natural bone mineral biocoated with

rhGDF-5 and rhBMP-2 in dogs.

Material and methods: Three standardized box-shaped defects

were surgically created at the buccal aspect of the alveolar ridge

in each quadrant of 8 beagle dogs. After 2 months of healing, the

chronic-type defects were randomly allocated in a split-mouth

design to either (i) BOG, or (ii) BOB biocoated with (a) rhGDF-5,

or (b) rhBMP-2, respectively. Uncoated grafts served as controls.

After 3 and 8 weeks, dissected blocks were prepared for im-

munohistochemical (osteocalcin – OC) and histomorphometri-

cal analysis [e.g. area (mm2) of new bone fill (BF), newly formed

mineralized- (MT) and nonmineralized tissue (NMT)]

Results: rhBMP-2 biocoated BOG revealed significantly highest

BF and MT values at 3 (upper and lower jaws – UJ/ LJ – compared

to BOG) and 8 weeks (UJ – compared to rhGDF-5). Biocoating of

BOB using both rhGDF-5 and rhBMP-2 resulted in significantly

increased MT values at 8 weeks (UJ/ LJ – compared to BOB). In

all groups, NMT adjacent to BOG and BOB scaffolds revealed

pronounced signs of an OC antigen reactivity.

Conclusions: Within the limits of the present study, it was

concluded that both rhGDF-5 and rhBMP-2 have shown effi-

cacy, however, their bone regenerative effect was markedly

influenced by the carrier.


Osseointegration of implants with biofunctionalizedsurfaces in comparison to the ANKYLOS

s

plusimplant surface

Schlegel KA1, Nonhoff J2, Nkenke E1, Lutz R1, Srour S1,Weisel T2, Neukam FW1

1Maxillofacial Surgery Department, Erlangen, 2Friadent GmbH,

Clinical Research, Mannheim

Purpose: The bone-to-implant interaction is a complex process,

which does not only depend on surface topography. In the early

stages of bone formation, which play the essential role for

osseointegration the chemical or biochemical composition of

implant surface also plays a crucial role. Thus, it could be

suggested that the biofunctionalization of implant surfaces

may interfere in the acceptance of the implant to the surround-

ing bone, enhancing the initial biologic response and lead to an

enhanced bone-to-implant contact.

Material and methods: Each six Ankyloss

implants with four

different surfaces (diameter 3.5 mm; length 8 mm) modified

with an indentation placed under the top of the implant were

randomly distributed and placed in the forehead region of 12

adult pigs. Each six animals were sacrificed after 14 or 30 days.

As four different implant surfaces were tested, 12 implants for

each surface and timepoint could be examined. Group A with

the plus surface (grit-blasted/acid-etched) as a control, group B

with the plus surface and an hydroxyapatite coating as refer-

ence, group C with hydroxyapatite coating and bioactive peptide

in a low concentration and group D with hydroxyapatite coating

and bioactive peptide in a high concentration.

Results: The histomorphometric analysis showed that the

implants with the Bioplus surface with the high concentration

of the bioactive peptide (group D) provided significantly higher

bone-to-implant contact rates (81.5%� 15.2 vs. 70.6%� 20.3

(group A); 67.4%� 28.8 (group B); 74.2%� 16.4 (group C);

p¼0.00 to p¼ 0.02) compared to the other groups after 14

days. After 30 days the bone-to-implant contact was signifi-

cantly increased in group C and D compared to the control

(84.0%� 17.0 (group C) and 81.6%� 16.1 (group D) vs.

65.2%� 22.8 (group A); p¼0.00 and 70.3%� 24.9 (group B)).

Conclusion: It could be shown that a biofunctionalization of the

implant surface with a bioactive peptide resulted in significantly

increased bone-to-implant contact rates after 14 and 30 days.


Elemental microanalysis following maxillary sinusaugmentation with Bio-Oss

s

or BoneCeramics

Lindgren CL1, Hallman MH2, Sennerby LS3, Sammons RS4

1Department of Oral & Maxillofacial Surgery, University Hospital,

Linkoping, Sweden, 2Department of Oral & Maxillofacial Surgery,

Gavle Hospital, Gavle, Sweden, 3Department of Biomaterials,

Institute for Surgical Sciences, Goteborg University, Sweden,4University of Birmingham School of Dentistry, UK

Objectives: To investigate the biocompatibility of a synthetic

biphasic calcium phosphate bone substitute material in com-

parison with anorganic bovine bone for human maxillary sinus

augmentation.

Material and methods: Maxillary sinus floor augmentation was

performed with anorganic bovine bone (ABB; Bio-Osss

, Geis-

tlich, Wolhusen, Switzerland) on one side andBoneCeramics

(BC; Straumann, Bern, Switzerland) on the other in 11 patients.

Simultaneously 22 microimplants were placed into the graft.

Eight months after the initial surgery all microimplants with

surrounding bone were harvested. Samples were examinedusing

back-scattered electron scanning electron microscopy and en-

ergy dispersive X-ray spectroscopy to identify the biomaterial

particles and analyse the elemental composition at the graft-

tissue interface.

857

Results: Large, 10–100 micronparticles of both materials were

present in direct contact with or completely surrounded by

newly-formed bone; smaller particles were also present in non-

organised tissue. Linescans across the material-bone interface

showed higher levels of Ca and P in BC in comparison with ABB

or bone but Ca/P ratios, determined from > 100 discreet sites

within residual particles or bone, were similar: 1.6� 0.07

(ABB), 1.5� 0.1 (BC) and 1.6� 0.1 (bone).

Conclusion: In this study equal osteoconductivity and material-

resistance to resorption was found comparing anorganic bovine

bone and a synthetic biphasic calciumphosphate used for aug-

mentation of the floor of the maxillary sinus. The material-bone

interface revealed higher levels of Ca and P in BC compared to

ABB or bone, but Ca/P ratios were similar.


A systematic review of GBR treatments for peri-implantitis defects

Sahrmann P1, Hammerle CHF2, Attin T1, Schmidlin PR1

1Clinic for Preventive Dentistry, Periodontology and Cariology, Center

for Dental and Oral Medicine, University of Zurich, Zurich, 2Clinic for

Fixed and Removable Prosthodontics and Dental Material Science,

Center for Dental and Oral Medicine, University of Zurich, Zurich

Aim: The aim of this systematic review was to assess the

available literature for GBR treatment of bony defects resulting

from peri-implantitis.

Methods: A MEDLINE and a manual search was conducted to

assess all types of clinical studies treating peri-implantitis

derived bone defects by using bone graft substitutes and mem-

branes. Articles up to and including December 2007 were

considered.

Results: During the first screening, 399 titles were identified.

Finally, eighteen articles reporting on 258 implants were in-

cluded. Only six studies assessed more than 7 peri-implantitis

cases. The articles mainly focussed on radiographic bone fill of

the defect. Qualitative measures of bone fill were reported:

25.6% of the implants showed complete ‘‘bone fill’’, whereas

60.4% revealed an incomplete defect resolution. No ‘‘bone fill’’

was shown in 4.7%. Little information (in 54.8%) was provided

for the probing depth before or after treatment. Data concerning

the inflammatory status of the soft tissues was also scarce and

reported only in four out of 18 studies. A large heterogeneity

concerning disinfection protocols and regenerative materials

used was found. The high percentage of low-quality studies

rendered a meta-analysis impossible.

Conclusion: Complete fill of bony defect caused by peri-im-

plantitis using GBR-protocol doesn’t seem to be predictable. The

mucosal health status is vastly neglected in the treatment of

defects resulting from peri-implantitis. Well-controlled trials are

needed to determine predictable treatment protocols for the

successful treatment of peri-implantitis derived bony defects

using GBR technique.


Effect of pharmacologic treatment on inferior alveolarnerve injury after implant surgery

Kim ST1, Kim HT2, Merrill R2

1TMJ & Orofacial Pain Clinic, Yonsei University, Dental College, Seoul,2Orofacial Pain Clinic, UCLA, School of Dentistry, Los Angeles

Injury of inferior alveloar nerve is one of the most common post-

operative complications after implant surgery. Usually the altered

sensation and neuropathic pain caused by the nerve injury are

temporary, but sometimes they result in permanent neurosensory

disorder. As an alternative, anticonvulsants and antidepressants has

been reported to be effective to post-operative neuropathic pain. The

aim of this study was to evaluate the effect of pharmacologic

treatment on inferior alveolar nerve injury after implant surgery.

For evaluation of the effects of anticonvulsants and antidepres-

sants on inferior alveolar nerve injury, 85 patients were enrolled in

this study, who visited TMJ & Orofacial pain clinic, with the

history of inferior alveolar nerve injury. Prospectively, their pain

characteristics, pain and discomfort level (VAS), and pain relieving

factors were investigated.

In results, the patients, who took anticonvulsants and antide-

pressants for at least 12 weeks, reported reduction in pain and

discomfort level, which was average 24.8% reduction. Interestingly

the patients, who have experienced the altered sensation and

neuropathic pain over a year, also reported reduction in pain and

discomfort level, with average of 17.1% reduction. In addition, we

found that early treatment using medications increased the reduc-

tion rate in pain and discomfort level. It is reported that the most

effective pain relieving factor in daily life was rest, sleep and use of

moist heat.

Based on this study, we could conclude that anticonvulsants and

antidepressants may be used as an alternative effective treatment to

relieve the altered sensation and neuropathic pain after inferior

alveolar nerve injury.


Accuracy of a CT guided template assisted implantplacement system: an in vitro study

Horwitz J, Zuabi O, Machtei EUnit of Periodontology, Department of Oral and Dental Medicine,

Rambam Health Care Campus, Haifa

Objectives: To evaluate the accuracy of computer assisted 3D

planning and implant insertion in pre and post operative CTs.

Material and methods: Six resin models with preexisting 3

implants in each (group C), were used. 9 implants in each model

were planned with Med3DTM

software on pre-operative CTs,

acquired with radiographic templates (group E). Templates were

converted into operative guides containing 5 mm diameter titanium

sleeves. A single set of insertable sleeves was used for consecutively

drilling the six models followed by MISs

SevenTM

implant insertion

through the guide sleeves. Group E implants was further divided

into group E1- the first 27 and group E2- the later 27 implants. Post-

operative CTs were used to compare implant positions with

858

pre-operative planned positions. Statistical analysis included Mann-

Whitney U test for pair-wise comparisons and Kruskal-Wallis Test

for the 3 groups.

Results: Mean apex depth deviations for groups E and C

(0.49 mm� 0.36SD and 0.32 mm� 0.21SD respectively),

and mean apex radial deviations (0.63 mm� 0.38SD and

0.49 mm� 0.17SD,) were similar for both groups (p > 0.05).

Mean angulation deviation was 2.171� 1.061SD and 1.321

� 0.691SD, p < 0.05. Significant differences were found with

the Kruskall-Wallis test between groups E1, E2 and C, the

differences being statistically significant when comparing E2

vs. C and E1 vs. E2.

Conclusions: Computer assisted implant planning and insertion

provides good accuracy. Deviations are mainly related to system

and reproducibility errors. A safety margin of 1.14 mm (3 times

the maximum SD) should be used when planning around vital

structures. Multiple use of drills and titanium sleeves signifi-

cantly reduces system accuracy.


Clinical results of anti-microbial photodynamictherapy for peri-implantitis

Neugebauer J, Karapetian VE, Lingohr T, Scheer M,Zoller JEDepartment for Oral Surgery and Implantology, Koln

The microbiological infection of the peri-implant tissue is still one

of the most difficult implant complications today. The anti-micro-

bial photodynamic treatment shows high levels of antimicrobial

reduction for all relevant bacterial strains in periodontology.

From 2003 till 2007, during regular implant recall, 31 patients

showed clinical signs of peri-implantitis including bleeding on

probing. The initial treatment concept included hygienic instruc-

tion, supragingival cleaning and determination of the cause of the

pathology. 22 patients with 44 implants showed a bone loss less

than the first thread and were classified as mucositis. 9 patients

show a bone loss of more than 4 mm and were stated as osseose-

paration. For reduction of peri-implant infection photodynamic

therapy (Helbo, Grieskirchen, Austria) by a thiazin-based dye and

a non thermal laser was applied.

In the osseoseparation group vertical bone defects were augmen-

ted in combination with photodynamic treatment of the surgical

site. Six month after treatment 64.3% showed no signs of infection.

In the mucositis group 7 patients received the implant treatment

after cancer rehabilitation with skin graft and suffered on super

infection with Candida. These patients were retreated by a se-

quence of antimicrobial treatments between 2 and 8 weeks. Other

patients in the mucositis group showed no clinical symptoms after

1.2 appointments in average for 96.2% of the implants.

The anti-microbial photodynamic treatment offers a bacteria

reduction without administering local anaesthesia and can be

repeated without any side effects. This non-invasive method allows

an early treatment of peri-implantitis prior to radiological signs of

bone loss.


Corrosion of magnetic attachments in implantdentistry

Boeckler AF1, Ehring C1, Morton D2, Geis-Gerstorfer J3,Setz JM1

1Martin-Luther-University Halle-Wittenberg, Centre for Dentistry and

Oral Medicine, Department of Prosthodontics, Halle (Saale),2University of Florida, Department of Oral and Maxillofacial Surgery

and Diagnostic Sciences, Center for Implant Dentistry, Gainesville, Fl,3University Hospital Tuebingen, Center for Dentistry and Oral

Medicine, Department of Medical Materials and Technology,

Tuebingen

Introduction: In the past the utilization of magnets as implant

attachments often failed due to lacking biocompatibility and their

high susceptibility to corrosion in the mouth. The aim of this

study was the standardized analyse of the corrosion behaviour of

contemporary magnetic attachments for dental implants.

Material and methods: 21 different components (n¼ 4) of mag-

netic implant attachments from different alloys (NdFeB, SmCo,

Ti, CrMoMnTiFe, etc) as delivered by the manufacturers (Tech-

novent-GB, Aichi-J, Brassler-G, Dyna-NL, Steco-G) were exam-

ined for their corrosion behaviour (statical-immersion-analysis-

ISO 10271:2001; Control: uncased-SmCo-magnet). The eluate

was examined (after 1-4-7-28-days) quantitatively on alloy com-

ponents (optical-emission-spectrometry [mg/cm2]). The results

were statistically analyzed and compared to the requirements of

ISO-22674:2006. (T-Test, Mann-Whitney-Wilcoxon-rank-sums-

test; p < 0.05).

Results: Dissolved-metal-ions could be found on all tested

products. The release after 1 and 4-days was different for all

specimens. After 7-days (Fe[13.94], Pd[1.53], Cr[1.32], Ti[1.09],

Co[0.81], B[0.6], Nd[0]) and after 28-days (Fe[173.58], Pd[44.17],

Cr[2.02], Ti[2.11], Co[26.13], B[1.77], Nd[79.18]) the ion-release

increased irregularly. The release of corrosion products of all

analysed products stayed significantly under the limit of 200 mg/

cm2 (ISO-22674:2006). The Control magnet exceeded that limit

significantly: after 7-days Sm[55.06], Co[86.83] and after 28-days

Sm[603.91], Co[950.56].

Conclusion: Metal-ions had dissolved on all specimens, but

below the threshold of ISO-22674: 2006. In one product the

magnet corroded and calls for improvement of the capsulation.

Within these limitations all products seem to be suitable for

dental implant application.

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short oral communications (oral presentations – abstracts 51 to 71)

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