Int Poster J Dent Oral Med 2000, Vol 2 No 3, Poster 46
12-year follow-up study of silicoated resin-bonded fixed partial dentures
Authors: Ali-Reza Ketabi, Thomas Kaus, Claudia Bergbreiter, Lothar Pröbster
Dept. of Prosthodontics, University of Tuebingen, Germany
General Session of the IADR
Resin-bonded fixed partial dentures (RBFPD) are a conservative approach for
the replacement of missing teeth. Aim of the present study was to evaluate
the clinical performance of silicoated RBFPD´s, whose metal retainer
surfaces were silicoated with the Silicoater (Kulzer Co ®., FRG) procedure.
Material and Methods
Patients and restorations:
Beginning 1986, 74 RBFPD´s (64 anterior and 10 posterior) were delivered
to 61 patients (Tab. 1). The clinical procedures were performed by one of
the authors (L.P.). Tooth preparation consisted of occlusal rest seats,
horizontal ledges, and vertical grooves (Fig. 1 ). All restorations were
cast in non-precious alloys, 60 in a NiCr-alloy (Wiron88®, BEGO Co.)
and 14 in a CoCr-alloy (Remanium CD®, Dentaurum Co.). All were veneered
with ceramics (Vita VMK 68®, Vita Co.). The retainer surfaces were treated
according to the manufacturer with the Silicoater procedure (sandblasting,
silicoating, and silanizing).
After enamel etching with phosphoric acid gel the FPD's were seated with
Microfill pontic (Kulzer company®), a bis-GMA light- and autocuring composite
Patients were followed up at least once a year. RBFPD´s loss or retainer
loosening were considered as failure, and the survival rates calculated with
the Kaplan-Meier method.
|Fig. 1: Tooth preparation
One patient could not be followed up at all. 29 (47.3 %) patients were rated
as drop out, as they did not appear for recall for more than one year within
the 12 year observation period.
The maximum observation time of all restorations was 11 ½ years. Figure
2 shows the survival curve (Kaplan-Meier), which was calculable for 11 ½
years. The survival rate after 10 years was 76.4 % ± 12 % (95 % confidence
interval). For the anterior bridges alone the calculated survival rate was
78 % ± 13 % after 10 years. 14 primary failures (18.9 % of all
restorations), i.e. retention loss of one or more retainers, were observed
after a mean function time of 4.1 years. 4 of the 14 RBFPD´s were rebonded,
thus a survival rate of 84.2 % ± 9 % (87.3 % ± 8.8 % for anterior
bridges alone) of functioning restorations was calculated after 10 years
(Fig. 3). One of the bridges failed after 30 months, was replaced with another,
which again failed after 31 months. The 9 other failures were treated with
3 failures were associated with carious lesions of the abutment teeth. 3
veneer fractures occurred, however, the bonding of the RBFPD's was not affected.
|Fig. 2: Kaplan-Meier curve of primary failures
||Fig. 3: Kaplan-Meier curve of functional
Discussion and Conclusions
Only few longitudinal clinical studies with an observation period of more
than 10 years have been published. As in our study a major difficulty is
the loss to follow-up during the final years, which is mainly due to the
inability to contact patients. Creugers et al. found a significant difference
between perforated anterior bridges with a survival rate of 49 % ± 7
% and etched anterior bridges with a survival rate of 57 % ± 7 % after
10.5 years (Creugers, N. H. et al. 1997). Williams et el. Reported of a 64
% survival rate after 10 years (Williams, V. D. et al. 1989). A calculated
survival rate of 60 % after 10 years was published by Pröbster and Henrich
(Pröbster, B. and Henrich, G. M. 1997). Our study showed an overall
survival rate of 76.4 % ± 12 % after 10 years. Considering the
95%-confidence interval, our results are comparable to the previously reported
results of Creugers, Williams and Pröbster.
It is concluded, that silicoated resin-bonded fixed partial dentures are
a viable treatment means with an acceptable success expectancy.
Creugers NH, De KR, van't Hof MA. Long-term survival data from a clinical
trial on resin-bonded bridges. J Dent (1997) 25(3-4):239-242.
Pröbster B and Henrich GM. 11-year follow-up study of resin-bonded fixed
partial dentures. Int J Prosthodont (1997) 10(3):259-268.
Williams VD, Thayer KE, Denehy GE, Boyer DB. Cast metal, resin-bonded prostheses:
a 10-year retrospective study [published erratum appears in J Prosthet Dent
1989 Jul;62(1):119]. J Prosthet Dent (1989) 61(4):436-441.
This Poster was submitted on 24.07.00 by
Dr. Ali-Reza Ketabi.
Dr. Ali-Reza Ketabi
Zentrum ZMK, Poliklinik für Prothetik
D - 72076 Tübingen