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Irena Sailer Sven MühlemannMarcel ZwahlenChristoph H. F. Hämmerle

David Schneider

Cemented and screw-retained implantreconstructions: a systematic review ofthe survival and complication rates

Authors’ affiliations:Irena Sailer, Sven Mühlemann, Christoph H. F.Hämmerle, David Schneider, Clinic of Fixed andRemovable Prosthodontics and Dental MaterialScience, University of Zurich, SwitzerlandMarcel Zwahlen, Institute of Social and PreventiveMedicine, University of Bern, Bern, Switzerland

Corresponding author:PD Dr. med. dent. Irena Sailer

Clinic of Fixed and Removable Prosthodontics andMaterial ScienceCenter of Dental MedicineUniversity of ZurichPlattenstr. 11CH 8032 Zurich, SwitzerlandTel.: +41 44 634 3260Fax: +41 44 634 4305e-mail: [email protected]

Conflicts of interest:Dr Irena Sailer has a consultancy agreement withVITA and research collaborations with 3M ESPE,Straumann, Astra, Ivoclar, DeguDent, Sirona. Theremaining authors have no potential conflicts todeclare.

Key words: biological complications, bridges, cemented, complication rates, failures, fixed,

fixed dental prostheses, full-arch, implant reconstruction, screw-retained, single crowns,

survival, systematic review, technical complications

Abstract

Objectives: To assess the 5-year survival rates and incidences of complications of cemented and

screw-retained implant reconstructions.

Methods: An electronic Medline search complemented by manual searching was conducted toidentify randomized controlled clinical trials (RCTs), and prospective and retrospective studies

giving information on cemented and screw-retained single-unit and multiple-unit implant

reconstructions with a mean follow-up time of at least 1 year. Assessment of the identified studies

and data abstraction were performed independently by three reviewers. Failure rates were

analyzed using Poisson regression models to obtain summary estimates and 95% confidence

intervals of failure rates and 5-year survival proportions.

Results: Fifty-nine clinical studies were selected from an initial yield of 4511 titles and the data

were extracted. For cemented single crowns the estimated 5-year reconstruction survival was 96.5%

(95% confidence interval (CI): 94.8 – 97.7%), for screw-retained single crowns it was 89.3% (95% CI:

64.9 – 97.1%) (P = 0.091 for difference). The 5-year survival for cemented partial fixed dental

prostheses (FDPs) was 96.9% (95% CI: 90.8 – 99%), similar to the one for screw-retained partial FDPs

with 98% (95% CI: 96.2 – 99%) (P = 0.47). For cemented full-arch FDPs the 5-year survival was 100%

(95% CI: 88.9 – 100%), which was somewhat higher than that for screw-retained FDPs with 95.8%(95% CI: 91.9 – 97.9%) (P = 0.54). The estimated 5-year cumulative incidence of technical

complications at cemented single crowns was 11.9% and 24.4% at screw-retained crowns. At the

partial and full-arch FDPs, in contrast, a trend to less complication at the screw-retained was found

than at the cemented ones (partial FDPs cemented 24.5%, screw-retained 22.1%; full-arch FDPs

cemented 62.9%, screw-retained 54.1%). Biological complications like marginal bone loss >2 mm

occurred more frequently at cemented crowns (5-year incidence: 2.8%) than at screw-retained ones

(5-year incidence: 0%).

Conclusion: Both types of reconstructions influenced the clinical outcomes in different ways, none

of the fixation methods was clearly advantageous over the other. Cemented reconstructions

exhibited more serious biological complications (implant loss, bone loss >2 mm), screw-retained

reconstructions exhibited more technical problems. Screw-retained reconstructions are more easily

retrievable than cemented reconstructions and, therefore, technical and eventually biological

complications can be treated more easily. For this reason and for their apparently higher biologicalcompatibility, these reconstructions seem to be preferable.

Introduction

Fixed implant reconstructions like single-

implant crowns and multiple-unit fixed den-

tal prostheses (partial FDPs) are well docu-

mented in the literature and nowadays fully

accepted as a treatment option for the

replacement of single or multiple missing

teeth (Pjetursson et al. 2007; Jung et al.

2008). The establishment of the osseointegra-

tion of dental implants has been thoroughly

investigated and found to be highly predict-

able (Esposito et al. 1998; Berglundh et al.

2002). Even more, the implant-borne recon-

structions themselves exhibit excellent clini-

cal survival rates. In a recent systematic

review, the implant-borne crowns and partial

FDPs exhibited high survival rates resem-

bling the ones of tooth-borne reconstructions,

amounting to 95% at 5-years (Pjetursson

et al. 2007). Albeit, the clinical success of

Date:Accepted 04 June 2012

To cite this article:

Sailer I, Mühlemann S, Zwahlen M, Hämmerle CHF,Schneider D. Cemented and screw-retained implantreconstructions: a systematic review of the survival andcomplication rates.Clin. Oral Implants Res. 23(Suppl. 6), 2012, 163–201doi: 10.1111/j.1600-0501.2012.02538.x

© 2012 John Wiley & Sons A/S 163


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dental reconstructions depends not only on

the survival rates but also on the amount of

technical or biological complications occur-

ring during clinical function. To improve the

clinical success, debates about the best mate-

rials and techniques for the implant-borne

reconstructions are constantly raised (Pjeturs-

son et al. 2007; Jung et al. 2008). One of

those actual debates deals with the ideal fixa-

tion method between the implant and the

reconstruction.

The fixation of an implant reconstruction

can either be accomplished by screw-retain-

ing the reconstruction on the implant or on a

screw-onto implant abutment, or by cement-

ing the reconstruction on standardized or cus-

tomized abutments. Initially, screw-retention

was used for full-arch FDPs in edentulous

patients (Adell et al. 1981, 1990; Albrektsson

et al. 1986). Single-unit reconstructions were

generally cemented on prefabricated cement-

onto abutments (Sharifi et al. 1994). Both

types of reconstructions exhibited satisfactory

clinical long-term outcomes (Adell et al.

1981; Jemt 2009). However, due to the need

for customized prosthetic components to

improve the aesthetic outcomes or a possible

misangulation of the implant, new compo-

nents like the cast-on UCLA abutment were

developed (Lewis et al. 1988, 1992). These

cast-on abutments allowed for both single-

unit screw-retained and cement-retained

reconstructions.

Both cementation and screw-retention

seem to have their benefits and shortcomings

in their clinical application (Michalakis et al.

2003; Chee & Jivraj 2006). Cemented implant

reconstructions clinically and technically

resemble the procedures used for tooth-borne

reconstructions. They might, therefore, be

easier to fabricate and to manipulate in the

patients’ mouths. Specific prefabricated

cement-onto or even customized abutments

are needed, though. Nowadays, the CAD/

CAM (Computer-aided design / Computer-

aided manufacturing) procedures enable a

broad application of customized abutments

and, as a consequence, the cemented recon-

structions have become the reconstruction of

choice in many clinical situations. One

shortcoming of cemented crowns and FDPs

is the difficulty with the removal of the

excess cement. In-vitro investigations have

shown that excess cement always remained

at the tested specimens, irrespective of sub-

mucosal position of the crown margin (Agar

et al. 1997; Linkevicius et al. 2011). More

distressing, in the clinical situation excess

cement was proven to cause peri-implantitis

(Wilson 2009). Another significant shortcom-

ing of the cemented reconstructions is that,

in case of problems, they are difficult or

impossible to remove without destruction,

for example, in cases of technical complica-

tions.

In contrast, the major benefit of the screw-

retained reconstructions is their retrievability

(Zarb & Schmitt 1990; Chee et al. 1998). Fur-

thermore, biological problems are rather unli-

kely to occur, provided that the

reconstruction exhibits a good fit (Keith et al.

1999). The horizontal and angular positioning

of the implant, however, is more delicate and

harbors less tolerance than when using

screw-retained reconstructions, because the

position of the screw access hole and the sur-

rounding material dimensions of the supra-

structure need to be considered. The opening

for the fixation screw should be preferably

placed in non-visible palatal or oral areas,

which is only possible if a respective implant

position and angulation is provided. Further-

more, the technical fabrication of screw-

retained reconstructions is more complex

because a customization of the reconstruc-

tion core is always needed. Technical compli-

cations like loosening of retaining screws or

fracture of the veneering ceramic have been

reported (Torrado et al. 2004).

Until today, very little scientific informa-

tion is available comparing the pros and cons

of cement-retention and screw-retention

(Michalakis et al. 2003; Sherif et al. 2011).

The decision between the two types of recon-

structions is difficult and rather a matter of

personal preference than scientific evidence.

To be applicable as alternatives in every clin-

ical situation the cemented and screw-

retained reconstructions need to exhibit simi-

lar survival and complications rates, though.

The objectives of this review, therefore,

were the following:

1) To obtain robust estimates of the 5-year

survival rates of cemented and screw-

retained single-unit and multiple-unit

reconstructions and their supporting

implants.2) To obtain robust estimates of the bio-

logical and technical complication rates

of the cemented and screw-retained

single-unit and multiple-unit reconstruc-

tions.

Materials and Methods

The focused PICO (problem, intervention,

comparison, outcome) question of the present

systematic review was, whether or not the

clinical survival and complication rates of

cemented implant reconstructions are similar

to the ones of screw-retained reconstructions.

The focused question was separately ana-

lyzed for three different kinds of fixed

implant-supported reconstructions: single

crowns, partial FDPs, and full-arch FDPs.

This review was performed by three review-

ers (IS, SM, and DS).

Search strategy and study selectionA general MEDLINE (PubMed search form

search from 1990 up to and including August

2011 was conducted for English- and Ger-

man-language articles in dental journals by

the three reviewers. For this purpose Mesh

terms and free text words were used. The

detailed search terms were as follows

“implant*”, “cement*” or “screw*”, “fix*”

or “retain*”, “single-crown”, “single crown”,

“FPD”, “FDP”, “bridge”, “reconstruct*”, and

“suprastruct*”. Furthermore, the terms

“long-term”, “long term”, “longterm”, “lon-

gitud*”, “survival” or “failure”, “compli-cat*”, “technical”, or “biological” were used

in the search. The search was limited to:

“human, clinical trial, RCT, case report, clin-

ical trial phase 1-4, comparative study, con-

trolled clinical trial, English abstract,

English, German.” In addition, Cochrane

Library and Embase searches were performed

applying the same search terms. The litera-

ture search was supported by a specialized

librarian.

Finally, the electronic search was comple-

mented by manual search of the bibliogra-

phies of recent reviews (Michalakis et al.2003; Weber & Sukotjo 2007; Chaar et al

2011).

All titles obtained were checked for rele-

vant clinical studies.

Inclusion criteria

The first aim of this extensive search was to

find randomized controlled clinical trials

(RCTs) comparing cemented and screw-

retained implant reconstructions.

The systematic review of the clinical liter-

ature, furthermore, included clinical studies

from all levels of evidence, that is, prospec-tive or retrospective cohort studies. The addi-

tional inclusion criteria for study selection

were as follows:

• the studies included a minimum of 10

patients;

• the studies reported on outcomes of final

reconstructions;

• the studies had a mean follow-up time of

the final reconstructions 1 year or more;

• the studies reported details of the fixation

mode of the respective final reconstruc-

tions; and

164 | Clin. Oral Implants Res. 23 (Suppl. 6), 2012/163–201 © 2012 John Wiley & Sons A/S

Sailer et al Systematic review of cemented and screw-retained implant reconstructions


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• the studies reported on partially or fully

dentate patients receiving implant-sup-

ported single crowns and/or FDPs (partial

or full-arch FDPs).

Studies were excluded where the patients

had not been examined clinically at the fol-

low-up visit, that is, publications based on

patient records, questionnaires, or interviews.

Selection of studies

Titles and abstracts of the searches were ini-

tially screened independently by the three

reviewers (IS, SM, and DS) for possible inclu-

sion in the review. The full text of all possi-

bly relevant studies was then obtained for

independent assessment by the reviewers.

Any disagreement regarding inclusion was

resolved by discussion.

Figure 1 describes the process of identify-

ing the 59 full-text articles on the clinical

performance of the cemented and screw-retained reconstructions selected from the

initial yield of 4511 titles.

For the analysis, the articles were divided by

the fixation method (cemented, screw-retained)

and into studies reporting on the following:

-single crowns

-multi-unit partial FDPs (including two to

four splinted crowns, three- to five-unit

partial FDPs, partial FDPs with/without can-

tilevers)

-full-arch FDPs (10 units or more)

Excluded Studies

Of the 520 full-text articles examined, 461

were excluded from the final analysis for

different reasons (for detailed information, see

reference list of excluded articles). Amongthose articles, unfortunately, one RCT com-

paring cemented and screw-retained crowns

(Vigolo et al. 2004) had to be excluded as well,

due to the fact that the report of the outcomes

of the reconstructions was based on patient

interviews and not on a clinical examination.

The main reasons for exclusion were as fol-

lows: no detailed information on the recon-

struction design or the clinical outcomes at

the follow-up visits, no detailed information

on the fixation method, a mean observation

period of the final reconstructions less than

1 year, no detailed analysis of the data andcase descriptions of failures without relevant

information on the entire patient cohort,

mixed reconstructions in one patient cohort,

and no detailed information on the respective

reconstructions and multiple publications on

the same patient cohorts.

Data extraction

Information on the survival proportions and

on the biological and technical complications

of the abutments and reconstructions was

extracted from the included studies. The

number of events and the corresponding totalexposure time of the reconstructions were

calculated.

Survival was defined as the implant and/or

the reconstruction remaining in situ for the

observation period with or without modifica-

tion.

The analysis of the technical complications

included loosening of the abutment/recon-

struction screws, fracture of the abutment/

reconstruction screws, de-cementation, chip-

ping/fracture of the veneer/reconstruction,

presence of a gap at the junction between

implant and abutment, and finally the totalnumber of technical complications.

The analysis of the biological complica-

tions encompassed bone loss of more than

2 mm, general soft tissue complications like,

for example, peri-implant infections, fistulas

or swelling, mucosal hypertrophy, and soft

tissue recession.

Data from allthe studies were extracted inde-

pendently by three reviewers (IS, SM, and DS),

using data extraction forms. Disagreement

regarding data extraction was resolved by con-

sensus.

Statistical analysis

Failure and complication rates were calculated

by dividing the number of events (failures or

complications) as the numerator by the total

time of the reconstructions being under obser-

vation as the denominator. The numerator

could usually be extracted directly from the

publication. If all patients/reconstructions had

a fixed follow-up time point, this was taken asthe observation period for all.

The total observation time was calculated

by taking the sum of the following:

1) Exposure time of reconstructions that

could be followed for the whole observa-

tion time.

2) Exposure time up to failure of the recon-

structions that were lost due to failure

during the observation time.

3) Exposure time up to the end of observa-

tion time for reconstructions that did not

complete the observation period for rea-sons such as death, change of address,

refusal to participate, nonresponse,

chronic illnesses, missed appointments,

and work commitments.

If all three components for the calculation

of the total exposure time were not available,

the total exposure time was estimated by

multiplying the mean follow-up time by the

number of constructions under observation.

For each study, event rates for the recon-

structions were calculated by dividing the

total number of events by the total recon-

struction exposure time in years. For further

analysis, the total number of events was con-

sidered to be Poisson distributed for a given

sum of abutment exposure years, and Poisson

regression with a logarithmic link-function

and total exposure time per study as an offset

variable was used (Kirkwood & Sterne

2003a). To assess heterogeneity of the study-

specific event rates, the Spearman goodness-

of-fit statistics and associated P-value were

calculated. If the goodness-of-fit P-value was

below 0.05, indicating heterogeneity, robust

Poisson regression (by calculating robust

standard errors for the summary rates) was

used to obtain a summary estimate of the

event rates, which incorporated the heteroge-

neity among studies. Five-year survival pro-

portions were calculated through the

relationship between event rate and survival

function S, S(T) = exp(-T *event rate), by

assuming constant event rates (Kirkwood &

Sterne 2003b). Five-year cumulative failure

rates were calculated by subtracting the five-

year survival proportion from one. The 95%

confidence intervals for the survival and

cumulative failure rates were calculated by

First electronic search:4511 titles selected

3714 articles excluded(titles not topic related)

797 abstracts independentlyselected by three reviewers

277 articles excluded(268 not topic related, 6 no

abstract available, 3 reviews)

520 full text articles

461 articles excluded

59 articles included for review

Fig. 1. Article selection.

© 2012 John Wiley & Sons A/S 165 | Clin. Oral Implants Res. 23 (Suppl. 6), 2012/163–201



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Table 1. Included articles – Overview

Study Authors Year Study design Center Implant system Reconstruction Jaw

Region of

jaw

Type of

fixation

1 Abboud et al. 2005; 2005 Prospective University Ankylos Single crown Maxilla

Mandible

Posterior Cement

2 Akca & Cehreli 2008; 2008 Prospective University ITI FDP Maxilla

Mandible

Nr Cement

3 Andersen et al. 2001; 2001 P rospective University Implant

Innovations

Single crown Maxilla Anterior Screw

4 Andersson et al.1998a;

1998 Prospective Specialized clinic Branemark Single crown MaxillaMandible

AnteriorPosterior

Cement

5 Andersson et al.

1998b;

1998 Prospective Private practices

Specialized clinic;

multicenter

Branemark Single crown Maxilla Anterior

Posterior

Cement

6 Astrand et al. 2000; 2000 Prospective University ITI Full arch Maxilla Full arch Screw

7 Astrand et al. 2004a; 2004 Prospective

split mouth

Private practices;

multicenter

Branemark

ITI

FDP Maxilla Posterior Screw

8 Astrand et al. 2004b; 2004 RCT Nr Astra Tech

Branemark

Full arch Maxilla

Mandible

Full arch Screw

9 Bambini et al. 2001; 2001 Retrospective Nr Threadloc

Spine

Single crown

FDP

Mandible Poster ior Screw

10 Bragger et al. 2005; 2005 Prospective University ITI Single crown Nr Nr CementA

1 1 Cannizza ro e t al.

2008a;

2008 RCT Nr Zimmer Tapered

SwissPlus

Single crown Maxilla

Mandible

Anterior,

posterior

Cement

1 2 Cecchinato et a l.

2008;

2008 RCT

multicenter

University Astra FDP Maxilla

Mandible

Canine to

molar

Screw

13 Cho et al. 2004; 2004 Prospective University Nr Single crown

FDP

Maxilla

Mandible

Anterior

Posterior

Screw

14 Cooper et al. 2007; 2007 Prospective University Astra Tech Single crown Maxilla Anterior Cement

15 Crespi et al. 2010 2010 Prospective Nr Outlink Single crown Maxilla Posterior Cement

16 Crespi et al. 2007; 2007 Prospective Nr Outlink Single crown

FDP

full arch

Maxilla

Mandible

Anterior

Posterior

Cement

17 Drago 2003; 2003 Prospective Specialiced clinic Osseotite Single crown Maxilla

Mandible

Nr Cement

1 8 Drago & Lazzara

2006;

2006 Prospective Private practices;

multicenter

Osseotite Sull arch Mandible Full arch Cement

Screw

1 9 Duncan et al. 2003; 2 003 Prospective

multicenter

Nr ITI Single crown

FDP

Maxilla

Mandible

Anterior

Posterior

Screw

Cement

20 Eliasson et al. 2006; 2006 Retrospective University Branemark FDP Maxilla

Mandible

Anterior

Posterior

Screw

21 Eliasson et al. 2010; 2010 Prospective University Paragon Full arch Mandible Full arch Screw

22 Fischer et al. 2008; 2008 RCT HospitalSpecialized clinic

Straumann Full arch Maxilla Full arch Cement

23 Froberg et al. 2006; 2006 Prospective Nr Branemark

TiUnite

Full arch Maxilla Full arch Screw

2 4 Fugazzott o et al.

2004;

2004 Retrospective Private practices;

multicenter

ITI TPS+SLA Single crown

FDP

full arch

All All Cement

Screw

25 Gallucci et al. 2009; 2009 Prospective University;

multicenter

Straumann FDP with

cantilevers

All Posterior Screw

26 Gallucci et al. 2011a; 2011 RCT University Straumann SP Single crown Maxilla Anterior Screw

27 Glauser et al. 2004;. 2004 P rospective University Branemark Mk II Single crown All Anterior to

premolar

Cement

28 Gotfredsen 2004; 2004 Prospective University Astra Tech ST Single crown Maxilla Anterior Cement

29 Guncu et al. 2008; 2008 RCT University Branemark Mk

III TiUnite

Single crown Mandible Posterior Cement

3 0 Halg et al. 2008; 2008 Ret rospective Pr ivat e practice St raumann FDP with/without

cantilevers

All Posterior Cement

3 1 Hellden et al. 2 003; 2003 Prospective Univers ity

Private practice;

multicenter

Cresco Ti API

syste,

FDP All All Screw

3 2 Henriks son & J emt

2004;

2004 Prospective University Branemark Mk

III

Single crown Maxilla Anterior Cement

33 Henry et al. 1995; 1995 Prospective Private practices Branemark Single crown All All Cement

34 Hjalmarsson et al.

2011;

2011 Retrospective Specialized clinic Astra Tech

Straumann

Biomet 3i

Branemark


35 Jemt 2009 2009 Retrospective University Branemark

machined

Single crown Maxilla Anterior

Premolar

Screw

Cement

3 6 Johns on & Pe rss on

2001;

2001 Prospective University Genetics

implant system

Single crown All All Cement




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using the 95% confidence limits of the event

rates. Multivariable Poisson regression was

used to formally compare reconstruction fixa-

tion types and to assess other study charac-

teristics. In case of zero events in all studies

of one group, exact Poisson regression with-

out robust standard errors was used. All P-

values are two-sided and analyses were per-

formed using Stata®, version 12 (StataCorp.

2011. Stata Statistical Software: Release 12.

College Station, TX: StataCorp LP http://

www.stata.com/support/faqs/resources/citing-

software-documentation-faqs/).

Results

Included studies

A total of 59 studies were included in the

analysis, giving information on the clinical

performance of cemented and screw-retained

implant-supported fixed reconstructions. The

characteristics of the selected studies are

shown in Table 1.

Unfortunately, no RCT comparing cemen-

ted and screw-retained fixed implant recon-

structions matching the inclusion criteria

was available. Solely nine RCTs comparing

different types of implants or prosthetic

materials were found, however, using the

same fixation method for the tested groups

(Astrand et al. 2004b; Cannizzaro et al.

2008a; Cecchinato et al. 2008; Fischer et al.

2008; Guncu et al. 2008; Schropp & Isidor

2008; Zembic et al. 2009; Larsson & Vult

von Steyern 2010; Gallucci et al. 2011a).

In addition 38 prospective and 12 retro-

spective studies were included in this

review. Among them were six studies,

which were included because they gave

detailed information on the survival of the

implants supporting cemented or screw-

retained reconstructions, although these

studies did not report on the reconstruction

outcomes (Naert et al. 2001; Murphy et al.

2002; Fugazzotto et al. 2004; Froberg et al.

2006; Guncu et al. 2008; Ortorp & Jemt

2009b) (Table 2).

All the studies chosen were published

within the past 14 years.

The studies were mainly conducted in an

institutional environment. Thirty-seven stud-

ies were performed at universities, eight at

specialized clinics or hospitals, and seven

were performed in private practices. In the

seven studies, the study setting was not

reported. Nine of the investigations were per-

formed as multicenter studies.

Table 1. (continued)

Study Authors Year Study design Center Implant system Reconstruction Jaw

Region of

jaw

Type of

fixation

37 Jung et al. 2008; 2008 Prospective University Straumann

Nobel Biocare

TiUnite

Single crown Mandible Posterior Screw

Cement

38 Karlsson et al. 1997; 1997 Prospective Specialized clinics;

multicenter

Astra Single crown All All Cement

3 9 Kemppainen et al.

1997;

1997 Prospective University ITI

Astra

Single crown All All Screw

Cement4 0 Lar sson & Vult von

Steyern 2010;

2010 RCT University Astra FDP All All Cement

41 Levine et al. 1999; 1999 Retrospective Private practices;

multicenter

Straumann Single crown All All Cement

Screw

42 Murphy et al. 2002; 2002 Prospective University Astra Full arch Mandible Full arch Screw

43 Naert et al. 2001; 2001 Prospective University Branemark

Nobel Biocare

FDP Maxilla

Mandible

Nr Screw

44 Nordin et al. 2007; 2007 Retrospective Private practice Straumann Full arch Maxilla Full arch Screw

45 Ortorp & Jemt 2008; 2008 Retrospective University Branemark FDP Mandible Nr Screw

46 Ortorp & Jemt

2009b;

2009 Prospective University Branemark Full arch Maxilla

Mandible

Full arch Screw

47 Ortorp & Jemt 2009a; 2009 Retrospective University Branemark Full arch mandible Full arch Screw

48 Palmer et al. 2000; 2000 Prospective Hospital Astra Single crown Maxilla Anterior Cement

4 9 Ras mus son et al.

2005;

2005 Prospective University TiOblast Astra Full arch Maxilla

Mandible

Nr Screw

5 0 Roma nos & Ne ntwig

2000;

2000 Retrospective University NobelBiocare Single crown Maxilla

Mandible

Molar Cement

51 Scholander 1999; 1999 Retrospective University Branemark Single crown Maxilla

Mandible

Nr CementB

52 Scheller et al. 1998; 1998 Prospective University

Private practice;

multicenter

Biomet3i

SPI Thommen

Single crown Maxilla

Mandible

Nr Cement

53 Schneider et al. 2011; 2011 Prospective University Biomet 3i Single crown Maxilla Anterior Cement

5 4 Schr opp & Isidor

2008;

2008 RCT University Osseotite 3i Single crown Maxilla

Mandible

Anterior

Premolar

CementC

55 Schwarz et al. 2010; 2010 P rospective University FRIA-LOC-

System

Full arch Mandible Nr Screw

56 Turkyilmaz 2006; 2006 Prospective University Branemark MK

III

Single crown Maxilla All Cement

5 7 Van Steenberghe

et al. 2005;

2005 Prospective University Branemark MK

III


58 Wannfors &

Smedberg 1999;

1999 Prospective Hospital NobelBiocare Single crown Maxilla

Mandible

Anterior Screw

Cement59 Zembic et al. 2009 2009 RCT University Branemark RP Single crown Maxilla

Mandible

Nr Cement

A) 67 single crowns cemented, 2 single crowns screw-retained

B) 256 single crowns cemented, 2 single crowns screw-retained

C) 40 single crowns cemented, 2 single crowns screw-retained




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Table 2. Summary of results for outcome “implant survival”

Study Authors Year

Total no. of

loaded

implants

Total no. of

drop-outs

Mean

follow-up

time (y)

Total no. of

failures after

load

Total

exposure

time

Estimated failure

rate (per 100 years) 95% CI

Single crown

Cement 1 Abboud

et al.

2005 20 0 1 1 20 5 0.13 – 27.86

4 Andersson

et al. 1

1998 65 5 5 1 307.5 0.33 0.01 – 1.81

5 Anderssonet al. 2

1998 34 4 5 0 170 0 0 – 2.17

10 Bragger

et al.

2005 69 Nr 10 5 665 0.75 0.24 – 1.75

11 Cannizzaro

et al.

2008 108 0 3 0 327 0 0 – 1.13

14 Cooper et al. 2007 43 11 3 3 120.6 2.49 0.51 – 7.27

15 Crespi et al. 2010 30 0 3 0 90 0 0 – 4.1

16 Crespi et al. 2007 147 0 1.5 0 220.5 0 0 – 1.67

19 Duncan

et al.

2003 22 0 3 0 66 0 0 – 5.59

24 Fugazzotto

et al.

2004 2615 Nr 2 30 5200 0.58 0.39 – 0.82

28 Gotfredsen 2004 20 0 5 0 100 0 0 – 3.69

29 Guncu et al. 2008 24 0 1 1 23.83 4.2 0.11 – 23.38

32 Henriks son &

Jemt

2004 18 0 1 0 18 0 0 – 20.49

33 Henry et al. 1995 50 1 1 0 50 0 0 – 7.38

36 Johnson &

Persson

2001 77 2 3 0 228 0 0 – 1.62

38 Karlsson

et al.

1997 43 4 2 0 86 0 0 – 4.29

39 Kemppainen

et al.

1997 86 1 1 0 87 0 0 – 4.24

48 Palmer et al. 2000 15 1 5 0 72.5 0 0 – 5.09

50 Romanos &

Nentwig

2000 58 0 2.44 2 139.08 1.44 0.17 – 5.19

51 Scholander 1999 258 Nr 5 2 1285 0.16 0.02 – 0.56

52 Scheller

et al.

1998 97 Nr 5 2 480 0.42 0.05 – 1.51

53 Schneider

et al.

2011 16 1 1 0 16 0 0 – 23.06

54 Schropp &

Isidor

2008 34 11 5 0 170 0 0 – 2.17

56 Turkyilmaz 2006 34 Nr 3 0 102 0 0 – 3.62

58 Wannfors &

Smedberg

1999 36 2 3 0 105 0 0 – 3.51

59 Zembic et al. 2009 40 12 3 0 102 0 0 – 3.62

Summary estimate 0.46 0.32 – 0.66

5 – year survival rate (%) 97.7 96.8 – 98.4

Screw 3 Andersen

et al.

2001 59 5 3 1 167 0.6 0.02 – 3.34

9 Bambini

et al.

2001 32 0 3 0 96 0 0 – 3.84

19 Duncan

et al.

2003 10 0 3 0 30 0 0 – 12.3

24 Fugazzotto

et al.

2004 102 Nr 2 1 203 0.49 0.01 – 2.74

26 Gallucci

et al.

2011 20 0 2 0 40 0 0 – 9.22

39 Kemppainen

et al.

1997 25 Nr 1 0 25 0 0 – 14.76

58 Wannfors &

Smedberg

1999 44 2 3 0 129 0 0 – 2.86


5-year survival rate (%) 98.6 96.6 – 99.4

Partial Fixed dental prosthesis

Cement 2 Akca &

Cehreli

2008 30 0 2.2 0 66 0 0 – 5.59

16 Crespi et al. 2007 147 0 1.5 0 220.5 0 0 – 1.67

19 Duncan

et al.

2003 19 0 3 0 57 0 0 – 6.47

24 Fugazzotto

et al.

2004 889 Nr 2 9 1769 0.51 0.23 – 0.97

30 Halg et al. 2008 78 6 5.3 3 389.55 0.77 0.16 – 2.25


5-year survival rate (%) 97.6 96.8 –

98.3




7/39

The studies reported on 14 different

implant systems.

Numbers of included reconstructions and respectivefollow-up times (Table 3)

Single crowns (SCs)

The 59 studies included 35 studies reporting

on a total of 1692 single crowns, of which

1408 were cemented and 284 were screw-

retained. The weighted mean follow-up time

of the crowns was 3.8 years for cemented and

2.4 years for screw-retained.

Partial FDPs

Fifteen studies reported on 740 partial FDPs,

118 cemented, and 622 screw-retained. The

weighted mean follow-up time of the cemen-

ted FDPs amounted to 4.2 years, and that of

the screw-retained FDPs to 6.2 years.

Full-arch FDPs

Sixteen studies reported on 681 full-arch

FDPs, 50 cemented, and 631 screw-retained.

The weighted mean follow-up time of the

cemented full-arch FDPs was 1.4 years and

for the screw-retained FDPs 6.1 years.


Study Authors Year

Total no. of

loaded

implants

Total no. of

drop-outs

Mean

follow-up

time (y)

Total no. of

failures after

load

Total

exposure

time

Estimated failure


Screw 7 Astrand

et al. 1

2004 148 2 3 2 439.5 0.46 0.06 – 1.64

9 Bambini

et al.

2001 64 0 3 0 192 0 0 – 1.92

12 Cecchinato

et al.

2008 321 35 5 3 1510 0.2 0.04 – 0.58

19 Duncan

et al.

2003 32 2 3 0 93 0 0 – 3.97

20 Eliasson

et al.

2006 371 4 9.5 10 3477 0.29 0.14 – 0.53

24 Fugazzotto

et al.

2004 33 Nr 2 0 66 0 0 – 5.59

25 Gallucci

et al.

2009 237 0 5 0 1185 0 0 – 0.31

31 Hellden

et al.

2003 190 21 3.7 3 699.9 0.43 0.09 – 1.25

43 Naert et al. 2001 305 Nr 5.8 1 2030.5 0.05 0 – 0.27

45 Ortorp &

Jemt

2008 351 Nr 8.6 10 1426 0.7 0.34 – 1.29



Full-arch reconstruction

Cement 16 Crespi et al. 2007 147 0 1.5 0 220.5 0 0 – 1.67

22 Fischer et al. 2008 139 6 5 4 690 0.58 0.16 – 1.48

24 Fugazzotto

et al.

2004 518 Nr 2 19 1017 1.87 1.12 – 2.92



Screw 6 Astrand

et al.

2000 157 10 1 2 156 1.28 0.16 – 4.63

8 Astrand

et al. 2

2004 371 Nr 5 13 1822.5 0.71 0.38 – 1.22

21 Eliasson

et al.

2010 167 30 5 0 760 0 0 – 0.49

23 Froberg

et al.

2006 89 Nr 1.5 0 133.5 0 0 – 2.76

24 Fugazzotto

et al.

2004 71 Nr 2 8 134 5.97 2.58 – 11.76

34 Hjalmar ssonet al.

2011 242 Nr 5 0 1210 0 0 – 0.3

42 Murphy

et al.

2002 123 8 5 0 615 0 0 – 0.6

44 Nordin et al. 2007 110 7 2 2 258.53 0.77 0.09 – 2.79

46 Ortorp &

Jemt 1

2009 719 Nr 7.8 15 2725 0.55 0.31 – 0.91

47 Ortorp &

Jemt 2

2009 1093 740 9 6 7914 0.08 0.03 – 0.17

49 Rasmusson

et al.

2005 199 Nr 10 0 3397 0 0 – 0.11

55 Schwarz

et al.

2010 185 Nr 4.5 19 789.75 2.41 1.45 – 3.76

57 Van

Steenberghe

et al.

2005 184 20 1 0 174 0 0 – 2.12






8/39

Implant survival

Data on implants lost in function were

reported in 33 patient cohorts (29 studies) on

single crowns (26 cemented, 7 screw-

retained), 15 patient cohorts (13 studies) on

partial FDPs (5 cemented, 10 screw-retained),

and 16 patient cohorts (15 studies) on full-

arch FDPs (3 cemented, 13 screw-retained).

The estimated 5-year survival rates of theimplants supporting the implant reconstruc-

tions ranged from 94.2% (cemented full-arch

FDPs) to 98.7% (screw-retained partial FDPs).

Detailed information on the included studies

for this analysis and the respective implant

survival rates at the different types of recon-

structions is given in Table 2 and Figs 2 – 7.

When comparing screw-retained with

cemented single crowns no statistically sig-

nificant difference was found with respect to

implant failure (event rate ratio = 0.63,

P = 0.32).

At partial FDPs a trend was observed

toward less implant failures at screw-retained

FDPs compared to cemented FDPs (event rate

ratio = 0.54, P = 0.07).

In the group with full-arch FDPs signifi-

cantly less implant failures were found at the

screw-retained bridges compared to the

cemented reconstructions (event rate

ratio = 0.27, P = 0.04).

Reconstruction survival

From 59 studies a total of 35 patient cohorts

(29 studies) provided data on single crown

survival (27 cemented, 10 screw-retained), 14

patient cohorts (12 studies) on FDP survival

(5 cemented, 9 screw-retained), and 17patient cohorts (13 studies) reported on the

survival of full-arch FDPs (3 cemented, 14

screw-retained).

Table 3 and Figs 8 – 13 give detailed infor-

mation on the included studies for this analy-

.46 (95% CI: .32 - .66)Zembic et al.,2009

Wannfors & Smedberg,1999

Turkyilmaz,2006

Schropp & Isidor,2008

Scholander ,1999

Schneider et al.,2011

Scheller et al.,1998

Romanos & Nentwig,2000

Palmer et al.,2000

Kemppainen et al.,1997

Karlsson et al.,1997

Johnson & Persson,2001

Henry et al.,1995

Henriksson & Jemt,2004

Guncu et al.,2008

Gotfredsen,2004

Fugazzotto et al.,2004Duncan et al.,2003

Crespi et al.,2010

Crespi et al.,2007

Cooper et al.,2007

Cannizzaro et al.,2008

Bragger et al.,2005

Andersson et al. 2,1998

Andersson et al. 1,1998

Abboud et al.,2005

0 5 10 15 20 25 30 35

Event rate per 100 years

Fig. 2. Implant survival rate for cemented single crowns.

.28 (95% CI: .12 - .69)



Gallucci et al. ,2011

Fugazzotto et al.,2004

Duncan et al.,2003

Bambini et al. ,2001

Andersen et al.,2001

0 5 10 15 20Event rate per 100 years

Fig. 3. Implant survival rate for screw-retained single crowns.




9/39

sis and the survival rates of the cemented

and the screw-retained reconstructions.

In general, the estimated 5-year survival

rates of the reconstructions ranged from

89.3% (screw-retained crowns) to 98.0%

(cemented full-arch FDPs).

Altogether 49 (3.2%) single crowns, 18

(2.7%) partial FDPs, and 32 (7.0%) full-arch

FDPs failed during follow-up. The main

reported reasons for the loss of the recon-

structions were loss of the supporting

implant (Schropp & Isidor 2008; Ortorp &

Jemt 2009a; Schwarz et al. 2010), fractures of

the reconstructions/frameworks (Scheller

et al. 1998; Jemt et al. 2003; Abboud et al.

2005; Gallucci et al. 2009), other technical

complications like chipping of the veneering

ceramic (Palmer et al. 2000; Bragger et al.

2005; Rasmusson et al. 2005), and, finally,

aesthetic problems not acceptable by the cli-

nician and/or the patient (Wannfors & Smed-

berg 1999).

At the single crowns more reconstructions

failed in the group with the screw-retained

crowns compared to cemented ones, how-

ever, this observation did not reach statistical

significance (event rate ratio = 3.22,

P = 0.09).

At the partial FDPs, in contrast, a tendency

toward less reconstruction failure was found

at the screw-retained FDPs compared to the

cemented ones (event rate ratio = 0.64,

P = 0.47).

In the group with full-arch FDPs three

studies contained data on cemented full-arch

FDPs and did not report on any failures (Dra-

go & Lazzara 2006; Crespi et al. 2007; Elias-

son et al. 2010). In contrast, 8 of the 14

studies on screw-retained full-arch FDPs

.48 (95% CI: .35 - .65)

Halg et al.,2008


Duncan et al.,2003

Crespi et al.,2007

Akca & Cehreli,2008

0 5 10Event rate per 100 years

Fig. 4. Implant survival rate for cemented partial FDPs.

.26 (95% CI: .14 - .48)

Ortorp & Jemt,2008

Naert et al.,2001

Hellden et al.,2003

Gallucci et al.,2009


Eliasson et al.,2006

Duncan et al.,2003

Cecchinato et al. ,2008


Astrand et al. 1,2004


Fig. 5. Implant survival rate for screw-retained partial FDPs.




10/39

reported on reconstruction failures (event rate

ratio = 1.9, P = 0.54).

Technical complications

Altogether 44 patient cohorts (34 studies)

reported on technical complications at single

crowns (30 cemented, 14 screw-retained), 16

patient cohorts (14 studies) reported on tech-

nical problems of partial FDPs (5 cemented,

11 screw-retained), and 20 patient cohorts (14

studies) reported on the technical outcomes

of full-arch FDPs (3 cement, 17 screw-

retained).

Table 4 gives detailed information on the

included studies for this analysis and the

technical complication rates of the cemented


The data extracted from these studies are

only allowed for statistical comparison of the

total number of technical complications, the

number of abutment and/or reconstruction

screw loosening, the number of screw frac-

tures, and the number of chipping of the

veneering ceramic. Other technical problems

were not reported or did not occur in the

investigations.

For single crowns, significantly more tech-

nical complications occurred at the screw-

retained reconstructions compared to the


P = 0.01). Loosening of the abutment and/or

reconstruction screws was the most frequent

technical problem at single crowns, occurring

significantly more often at screw-retained

than at cemented crowns (event rate

ratio = 6.0, P < 0.005). Screw fracture (abut-

ment screw) tended to occur more often at

cemented crowns. For this parameter 18

studies (14 cemented, 4 screw-retained) were

1.19 (95% CI: .49 - 2.89)


Fischer et al.,2008

Crespi et al.,2007


Fig. 6. Implant survival rate for cemented full-arch FDPs.

.32 (95% CI: .12 - .85)

van Steenberghe et al.,2005

Schwarz et al.,2010

Rasmusson et al.,2005

Ortorp & Jemt 2,2009


Nordin et al.,2007

Murphy et al.,2002

Hjalmarsson et al.,2011


Froberg et al.,2006



Astrand et al.,2000

0 5 10 15Event rate per 100 years

Fig. 7. Implant survival rate for screw-retained full-arch FDPs.




11/39

Table 3. Summary of results for outcome “reconstruction survival”

Study Authors Year

Total no. of

included

reconstructions

Total no. of

drop-outs

Mean

follow-up

time (y)

Total no.

of failures

Total

exposure

time

Estimated failure


Single crown

Cement 1 Abboud et al. 2005 20 0 1 1 19.04 5.25 0.13 – 29.26

4 Andersson

et al. (1)

1998 65 6 5 4 294 1.36 0.37 – 3.48

5 Andersson

et al. (2)

1998 38 4 5 1 181.75 0.55 0.01 – 3.07

10 Bragger et al. 2005 69 5 10 2 655 0.31 0.04 – 1.1

11 Cannizzaro

et al.

2008 108 0 3 0 324 0 0 – 1.14

14 Cooper et al. 2007 51 8 3 0 141 0 0 – 2.62

15 Crespi et al. 2010 30 30 3 0 90 0 0 – 4.1

16 Crespi et al. 2007 9 0 1.5 0 13.5 0 0 – 27.33

17 Drago 2003 110 6 1 0 107 0 0 – 3.45

19 Duncan et al. 2003 22 0 3 0 66 0 0 – 5.59

27 Glauser et al. 2004 54 18 4.1 0 184.5 0 0 – 2

28 Gotfredsen 2004 20 0 5 1 97.5 1.03 0.03 – 5.71

32 Henriks son &

Jemt

2004 18 0 1 0 18 0 0 – 20.49

33 Henry et al. 1995 50 0 1 1 49.5 2.02 0.05 – 11.26

35 Jemt 2009 23 5 5 1 100 1 0.03 – 5.57

36 Johnson &

Persson

2001 78 1 3 1 231 0.43 0.01 – 2.41

38 Karlsson et al. 1997 47 4 2 0 90 0 0 – 4.1

48 Palmer et al. 2000 15 1 5 1 70 1.43 0.04 – 7.96

50 Romanos &

Nentwig

2000 58 2 1.72 2 96.32 2.08 0.25 – 7.5

51 Scholander 1999 258 5 5 8 1257.5 0.64 0.27 – 1.25

52 Scheller et al. 1998 97 32 5 8 382 2.09 0.9 – 4.13

53 Schneider

et al.

2011 16 1 1 0 15.5 0 0 – 23.8

54 Schropp &

Isidor

2008 42 5 5 3 193 1.55 0.32 – 4.54

56 Turkyilmaz 2006 34 0 3 1 100.5 1 0.03 – 5.54

58 Wannfors &

Smedberg

1999 27 1 3 0 79.5 0 0 – 4.64

58 Wannfors &

Smedberg

1999 9 1 3 0 25.5 0 0 – 14.47

59 Zembic et al. 2009 40 12 3 0 102 0 0 – 3.62

Summary estimate 0.70 0.46 –

1.085-year survival rate (%) 96.5 94.8 – 97.7

Screw 3 Andersen

et al.

2001 28 2 3 1 79.5 1.26 0.03 – 7.01

3 Andersen

et al.

2001 31 3 3 1 87 1.15 0.03 – 6.4

9 Bambini et al. 2001 32 0 3 0 96 0 0 – 3.84

19 Duncan et al. 2003 10 0 3 0 30 0 0 – 12.3

26 Gallucci et al. 2011 10 0 2 0 20 0 0 – 18.44

26 Gallucci et al. 2011 10 0 2 0 20 0 0 – 18.44

35 Jemt 2009 18 5 5 0 77.5 0 0 – 4.76

39 Kemppainen

et al.

1997 101 0 1 0 101 0 0 – 3.65

58 Wannfors &

Smedberg

1999 36 2 3 10 86 11.63 5.58 – 21.38

58 Wannfors &Smedberg 1999 8 0 3 2 22 9.09 1.1 –

32.84



Partial Fixed dental prosthesis

Cement 2 Akca &

Cehreli

2008 15 0 2.2 0 33 0 0 – 11.18

16 Crespi et al. 2007 15 0 1.5 0 22.5 0 0 – 16.4

19 Duncan et al. 2003 9 0 3 0 27 0 0 – 13.66

30 Halg et al. 2008 54 2 5.3 3 272.95 1.1 0.23 – 3.21

40 Lars son & Vult

von Steyern

2010 25 0 5 0 125 0 0 – 2.95






12/39

analyzed, showing 2 studies reporting on

screw fractures in the cemented group (Karls-

son et al. 1997; Romanos & Nentwig 2000)

and no screw fractures in the screw-retained

group. Finally, chipping of the veneering cera-

mic tended to occur more frequently at the

screw-retained reconstructions (event rate

ratio = 3.6, P = 0.08).

At FDPs a trend to less total technical

complications was observed at the screw-

retained reconstructions compared to the



reconstruction screws was only reported in

studies on screw-retained FDPs and did not

occur on cemented FDPs. Due to the lack of

events for cemented FDPs, a statistical com-

parison (regression) was not possible. The

same applies to the technical parameter, the

screw fractures. Fractures of the retaining

screws were reported in five of the seven

included studies on screw-retained FDPs and

in none of the three studies included on

cemented FDPs. Finally, chipping of the

veneering ceramic tended to occur more fre-

quently at the screw-retained FDPs (event

rate ratio = 0.5).

At full-arch FDPs a trend to less total tech-

nical complications was observed at the

screw-retained reconstructions compared to

the cemented ones (event rate ratio = 0.62,


reconstruction screws tended to occur more

frequently at screw-retained FDPs (event rate

ratio = 3.1, P = 0.09). Screw fracture was only

reported in five of the seven studies with

screw-retained full-arch FDPs; no screw frac-

tures occurred at the cemented ones (two

studies). Due to the zero events of cemented

full-arch FDPs, again a statistical comparison

(regression) was not possible. Chipping of the

veneering ceramic was significantly less fre-

quently observed at the screw-retained FDPs

(event rate ratio = 0.24, P < 0.005).

Biological complications

Altogether 29 patient cohorts (25 studies)

reported on biological complications at single

crowns (22 cemented, 7 screw-retained), 9

patient cohorts (8 studies) reported on techni-

cal problems of partial FDPs (2 cemented, 7


Study Authors Year

Total no. of

included

reconstructions

Total no. of

drop-outs

Mean

follow-up

time (y)

Total no.

of failures

Total

exposure

time

Estimated failure


Screw 7 Astrand et al.

1

2004 56 4 3 0 162 0 0 – 2.28

9 Bambini et al. 2001 64 0 3 0 192 0 0 – 1.92

12 Cecchinato

et al.

2008 115 11 5 2 542.5 0.37 0.04 – 1.33

19 Duncan et al. 2003 16 1 3 0 46.5 0 0 – 7.9320 Eliasson et al. 2006 146 0 9.5 4 1368 0.29 0.08 – 0.75

25 Gallucci et al. 2009 45 0 5 2 218.55 0.92 0.11 – 3.31

31 Hellden et al. 2003 60 8 3.7 1 205.35 0.49 0.01 – 2.71

45 Ortorp & Jemt 2008 60 22 8.47 0 508 0 0 – 0.73

45 Ortorp & Jemt 2008 60 16 8.83 6 530 1.13 0.42 – 2.46



Full-arch reconstruction

Cement 16 Crespi et al. 2007 11 0 1.5 0 16.5 0 0 – 22.36

18 Drago &

Lazzara

2006 15 0 1.5 0 22.5 0 0 – 16.4

22 Fischer et al. 2008 24 1 5 0 117.5 0 0 – 3.14

Summary estimate 0 0 – 2.36

5-year survival rate (%) 100 88.9 – 100%

Screw 6 Astrand et al. 2000 28 1 1 0 27.5 0 0 – 13.41

8 Astrand et al.

2

2004 66 3 5 1 322.5 0.31 0.01 – 1.73

18 Drago &

Lazzara

2006 12 0 1.5 0 18 0 0 – 20.49

21 Eliasson et al. 2010 29 5 5 0 132.5 0 0 – 2.78

34 Hjalmar sson

et al.

2011 40 0 5 1 197.5 0.51 0.01 – 2.82

44 Nordin et al. 2007 19 1 2.51 0 46.435 0 0 – 7.94

45 Ortorp & Jemt

1

2009 62 25 7.67 1 475.5 0.21 0.01 – 1.17

45 Ortorp & Jemt

1

2009 67 32 7.82 2 524 0.38 0.05 – 1.38

46 Ortorp & Jemt

2

2009 53 40 6.81 0 361 0 0 – 1.02

46 Ortorp & Jemt

2

2009 51 31 8.02 8 409 1.96 0.84 – 3.85

46 Ortorp & Jemt

2

2009 104 72 7.19 14 748 1.87 1.02 – 3.14

49 Rasmusson

et al.

2005 36 8 10 1 315 0.32 0.01 – 1.77

55 Schwarz et al. 2010 37 0 4.5 4 157.5 2.54 0.69 – 6.5

57 Van

Steenberghe

et al.

2005 27 3 1 0 25.5 0 0 – 14.47






13/39

screw-retained), and 17 patient cohorts (12

studies) reported on the technical outcomes

of full-arch FDPs (1 cement, 16 screw-

retained).

5 gives detailed information on the

included studies for this analysis and the bio-

logical complication rates of the cemented


Bone loss exceeding 2 mm occurred in 6 of

the 23 studies on single crowns that were

included for this analysis. In all these six stud-

ies cement-retained crowns were used. Since

the event rate was 0 at the screw-retained

crowns, a statistical regression analysis

between the two groups was not possible.

Screw-retained single crowns, however,

exhibited statistically more soft tissue com-

plications like peri-implant infections, fistu-

las or swelling, and mucosal hypertrophy

(event rate ratio = 6.3, P < 0.005). Finally,

soft tissue recession tended to occur more

frequently at cemented crowns. Five of the

eight studies on cemented crowns reported

soft tissue recessions, in contrast, none of

the two studies on screw-retained crowns

observed that problem.

At partial FDPs, bone loss occurred signifi-

cantly less frequently at screw-retained

reconstructions than at cemented ones (event

rate ratio = 0.38, P = 0.01). Soft tissue com-

plications were only reported in the studies

on screw-retained FDPs. One study reporting

on cemented FDPs showed no soft tissue

complications (Duncan et al. 2003). Reces-

sions were not reported nor analyzed in the

studies on partial FDPs.

A similar observation was made at the full-

arch FDPs. Bone loss occurred significantly

less frequently at the screw-retained bridges

2.25 (95% CI: .59 - 8.65)




Jemt,2009



Duncan et al.,2003




0 5 10 15 20 25 30 35 40Event rate per 100 years

Fig. 9. Reconstruction survival rate for screw-retained single crowns.

.7 (95% CI: .46 - 1.08)Zembic et al.,2009



Turkyilmaz,2006

Schropp & Isidor,2008

Scholander ,1999

Schneider et al.,2011

Scheller et al.,1998

Romanos & Nentwig,2000

Palmer et al.,2000

Karlsson et al.,1997

Johnson & Persson,2001

Jemt,2009

Henry et al.,1995Henriksson & Jemt,2004

Gotfredsen,2004

Glauser et al.,2004

Duncan et al.,2003

Drago,2003

Crespi et al.,2010

Crespi et al.,2007

Cooper et al.,2007

Cannizzaro et al.,2008

Bragger et al.,2005

Andersson et al. (2),1998

Andersson et al. (1),1998

Abboud et al.,2005

0 5 10 15 20 25 30 35Event rate per 100 years

Fig. 8. Reconstruction survival rate for cemented single crowns.




14/39

(event rate ratio = 0.28, P < 0.005). For the

analysis of soft tissue complications only

studies on screw-retained reconstructions

were available. In 13 of the included 15 stud-

ies, soft-tissue problems were reported.

Recessions were not analyzed nor reported in

the studies on full-arch FDPs.

Discussion

This systematic review of the literature indi-

cated interesting differences in the perfor-

mance of cemented and screw-retained

implant reconstructions, depending on the

extension of the reconstructions.

With respect to the implant survival, no

differences were found regarding the

estimated 5-year survival rates of implants

supporting single crowns when cemented and

screw-retained crowns were compared.

However, in case of partial FDPs a trend was

found to more implant failures at cemented

reconstructions. At full-arch FDPs signifi-

cantly more implant failures occurred with

cemented reconstructions compared to

screw-retained ones. Hence, the incidence of

implant loss appeared to be higher at the

cemented reconstructions and increased with

the size of the reconstruction.

The respective reconstruction survival

rates of the different reconstruction types

exhibited a contrary behavior than the

implant survival rates. Screw-retained single

crowns showed lower estimated 5- year

survival rates than cemented crowns. The

difference, however, did not reach statistical

significance. The survival rates of the screw-

retained multi-unit reconstructions did not

differ from the ones of the cemented recon-

structions.

Technical complications were generally

more often observed with screw-retained

reconstructions than with cemented recon-

.4 (95% CI: .2 - .78)

Ortorp & Jemt,2008

Ortorp & Jemt,2008

Hellden et al.,2003

Gallucci et al.,2009


Duncan et al.,2003

Cecchinato et al. ,2008



0 5 10


Fig. 11. Reconstruction survival rate for screw-retained partial FDPs.

.62 (95% CI: .2 - 1.93)

Larsson & Vult von Steyern,2010

Halg et al.,2008

Duncan et al.,2003

Crespi et al.,2007

Akca & Cehreli,2008

0 5 10 15 20Event rate per 100 years

Fig. 10. Reconstruction survival rate for cemented partial FDPs.




15/39

structions. More specifically, higher rates for

loosening of abutment/ reconstruction screws

and chipping of the veneering ceramic were

found at screw-retained reconstructions com-

pared to cemented ones.

In contrast, the incidence of serious biolog-

ical complications, like bone loss exceeding

2 mm, was higher with cemented reconstruc-

tions. This complication was specifically

present at the multi-unit reconstructions.

Soft tissue inflammation was found at both

types of reconstructions, however, signifi-

cantly more often with screw-retained recon-

structions. This complication was reported to

be associated with excess cement (Bornstein

et al. 2003; Abboud et al. 2005) or, more pre-

dominantly, with loose abutment screws

(Andersen et al. 2001).

Hence, while the screw-retained recon-

structions suffered from more technical prob-

lems and needed more often repair or

replacement of the reconstructions, the

cemented reconstructions more frequently

experienced serious biological problems like

bone loss >2 mm or loss of the implant,

which may be more difficult to resolve clini-

cally. None of the two types of fixation, how-

ever, was clearly advantageous over the

other.

In the following sections, the findings

regarding the parameters will be interpreted

individually with aid of published results of

other reviews or clinical studies.

Implant survival

In general, the estimated 5-year survival rates

of the implant crowns and FDPs in this sys-

tematic review were in accordance with the

results of previous systematic reviews. In a

0 (95% CI: 0 - 2.36)

Fischer et al.,2008

Drago & Lazzara,2006

Crespi et al.,2007

0 5 10 15 20 25


Fig. 12. Reconstruction survival rate for cemented full-arch FDPs.

.85 (95% CI: .43 - 1.7)

van Steenberghe et al.,2005

Schwarz et al.,2010

Rasmusson et al.,2005






Nordin et al.,2007

Hjalmarsson et al.,2011


Drago & Lazzara,2006


Astrand et al.,2000

0 5 10 15 20 25Event rate per 100 years

Fig. 13. Reconstruction survival rate for screw-retained full-arch FDPs.




16/39

T a b l e

4 .

S u m m a r y o f r e s u l t s f o r o u t c o m e

“ t e c h n i c a l c o m p l i c a t i o n s ”

S t u d y

A u t h o r

Y e a r

T o t a l n o . o f

r e c o n s t r u c t i o n s

M e a n

f o l l o w - u p

t i m e ( y )

T o t a l

e x p o s u r e

t i m e

E s t i m a t e d r a t e o f t o t a l t e c h n i c a l

c o m p l i c a t i o n s ( p e r 1 0 0 y e a r s )

E s t i m a t e d r a t e o f s c r e w

l o o s e n i n g ( p e r 1 0 0 y e a r s )


f r a c t u r e ( p e r 1 0 0 y e a r s )

E s t i m a t e d r a t e o f

c h i p p i n g ( p e r

1 0 0 y e a r s )

S i n g l e c r o w n

C e m e n t

1

A b b o u d e t a l .

2 0 0 5

2 0

1

1 9 . 0

4

5 . 2

5

0

N a

N a

4

A n d e r s s o n

e t a l . ( 1 )

1 9 9 8

6 5

5

2 9 4

1 . 3

6

0 . 3

4

0

N a

5

A n d e r s s o n

e t a l . ( 2 )

1 9 9 8

3 8

5

1 8 1 . 7

5

0 . 5

5

0

0

0

1 0

B r a g g e r e t a l .

2 0 0 5

6 9

1 0

6 5 5

0 . 9

2

0 . 4

6

0

0 . 4

6

1 1

C a n n i z z a r o

e t a l .

2 0 0 8

1 0 8

3

3 2 4

2 . 7

8

0 . 3

1

0

0 . 6

2

1 4

C o o p e r e t a l .

2 0 0 7

5 1

3

1 4 1

3 . 5

5

0

0

2 . 1

3

1 5

C r e s p i e t a l .

2 0 1 0

3 0

3

9 0

0

0

0

N a

1 6

C r e s p i e t a l .

2 0 0 7

9

1 . 5

1 3

0

0

0

0

1 7

D r a g o

2 0 0 3

1 1 0

1

1 3 . 5

0 . 9

3

0 . 9

3

0

N a

1 9

D u n c a n e t a l .

2 0 0 3

2 2

3

6 6

0

0

0

N a

2 7

G l a u s e r e t a l .

2 0 0 4

5 4

4 . 1

1 8 4 . 5

2 . 2

6

0 . 9

0

1 . 3

6

2 8

G o t f r e d s e n

2 0 0 4

2 0

5

9 7 . 5

2 . 7

1

1 . 0

8

N a

1 . 0

8

3 2

H e n r i k s s o n &

J e m t

2 0 0 4

1 8

1

1 8

0

N a

0

0

3 3

H e n r y e t a l .

1 9 9 5

5 0

1

4 9 . 5

1 0 . 1

4 . 0

4

N a

2 . 0

2

3 5

J e m t

2 0 0 9

2 3

5

1 0 0

1 4

3

N a

N a

3 6

J o h n s o n &

P e r s s o n

2 0 0 1

7 8

3

2 3 1

5 . 1

9

2 . 6

N a

N a

3 7

J u n g e t a l .

2 0 0 8

7 8

3 . 6

2 8 0 . 8

4 . 2

7

N a

N a

N a

3 7

J u n g e t a l .

2 0 0 8

9 7

3 . 6

3 4 9 . 2

0 . 8

6

N a

N a

N a

3 8

K a r l s s o n

e t a l .

1 9 9 7

4 7

2

9 0

8 . 8

9

N a

1 . 1

1

1 . 1

1

4 1

L e v i n e e t a l .

1 9 9 9

8 2

3 . 3

2 6 0 . 7

3 . 0

7

1 . 5

3

N a

N a

4 8

P a l m e r e t a l .

2 0 0 0

1 5

5

7 0

2 . 8

6

0

N a

1 . 4

3

5 0

R o m a n o s &

N e n t w i g

2 0 0 0

5 8

1 . 7

2

9 6 . 3

2

1 . 0

4

N a

1 . 0

4

N a

5 1

S c h o l a n d e r

1 9 9 9

2 5 8

5

1 2 5 7 . 5

1 . 8

3

0 . 8

N a

0 . 0

8

5 2

S c h e l l e r e t a l .

1 9 9 8

9 7

5

3 8 2

1 . 8

3

1 . 0

5

N a

N a

5 3

S c h n e i d e r

e t a l .

2 0 1 1

1 6

1

1 5 . 5

0

N a

N a

N a

5 4

S c h r o p p &

I s i d o r

2 0 0 8

4 2

5

1 9 3

3 . 1

1

0

0

0

5 6

T u r k y i l m a z

2 0 0 6

3 4

3

1 0 0 . 5

1 . 9

9

N a

N a

1

5 8

W a n n f o r s &

S m e d b e r g

1 9 9 9

2 7

3

7 9 . 5

1 2 . 5

8

1 . 2

6

N a

1 . 2

6

5 8

W a n n f o r s &

S m e d b e r g

1 9 9 9

9

3

2 5 . 5

0

0

N a

0

5 9

Z e m b i c e t a l .

2 0 0 9

4 0

3

1 0 2

1 . 9

6

0

N a

1 . 9

6

S u m m a r y e s t i m a t e ( 9 5 %

C I )

2 . 5

3 ( 1 . 8

5 – 3 . 4

8 )

0 . 7

9 ( 0 . 5

6 – 1 . 1

2 )

0 . 0

8 ( 0 . 0

2 – 0 . 3

7 )

0 . 5

7 ( 0 . 2

8 – 1 . 1

4 )

5 - y e a r f a i l u r e r a t e ( 9 5 %

C I )

1 1 . 9

%

( 8 . 8

% – 1 6 . 0

% )

3 . 9

% ( 2 . 8

% – 5 . 4

% )

0 . 4

%

( 0 . 1

% – 1 . 8

% )

2 . 8

%

( 1 . 4

% – 5 . 5

% )




17/39

T a b l e

4 .

( c o n t i n u e d )

S t u d y

A u t h o r

Y e a r

T o t a l n o . o f

r e c o n s t r u c t i o n s

M e a n

f o l l o w - u p

t i m e ( y )

T o t a l

e x p o s u r e

t i m e

E s t i m a t e d r a t e o f t o t a l t e c h n i c a l

c o m p l i c a t i o n s ( p e r 1 0 0 y e a r s )


l o o s e n i n g ( p e r 1 0 0 y e a r s )


f r a c t u r e ( p e r 1 0 0 y e a r s )

E s t i m a t e d r a t e o f

c h i p p i n g ( p e r

1 0 0 y e a r s )

S c r e w

3

A n d e r s e n

e t a l .

2 0 0 1

2 8

3

7 9 . 5

5 . 0

3

5 . 0

3

N a

N a

3

A n d e r s e n

e t a l .

2 0 0 1

3 1

3

8 7

4 . 6

4 . 6

N a

N a

9

B a m b i n i e t a l .

2 0 0 1

3 2

3

9 6

3 . 1

3

3 . 1

3

0

N a

1 3

C h o e t a l .

2 0 0 4

3 9

5

1 9 5

2 . 0

5

2 . 0

5

N a

N a

1 9

D u n c a n e t a l .

2 0 0 3

1 0

3

3 0

6 . 6

7

6 . 6

7

0

N a

2 6

G