CLINICAL CASE

CLINICAL CASE
Dent. Med. Probl. 2007, 44, 4, 521–525
ISSN 1644−387X
© Copyright by Silesian Piasts University of Medicine in Wrocław
and Polish Stomatological Association
TOMASZ DĄBROWA, HALINA PANEK, PIOTR NAPADŁEK
8−Year Clinical Observation of Telescopic Anchors
Applied in Removable Dentures – Case Report
8−letnie obserwacje kliniczne zaczepów teleskopowych
zastosowanych w protezach ruchomych – opis przypadku
Department of Prosthodontics, Silesian Piasts University of Medicine in Wrocław, Poland
Abstract
The authors of the paper presented a clinical evaluation of telescopic anchors applied in order to enhance the sta−
bility of the lower partial removable denture. The main clinical and laboratory stages in performance of the remov−
able denture were described and the method of evaluation of the denture’s retention was presented. The conical
telescopic anchors were applied as the attachments for the removable denture. The framework of the denture was
cast from chromium−cobalt−molibdenium alloy, and the external telescopic crowns were veneered with composite
resin. After 8−year clinical observation of one of the first patients with this plan of treatment, authors concluded,
that this system has many advantages, which make it highly recommendable in elderly patients with reduced eye−
sight and inadequate motion abilities. On discussion, the problem of retention and the influence of these kind of
dentures on periodontal tissues was brought up. The characteristic features of this system are: satisfying retention
and stability of dentures during mastication, splinting effect, accessibility for oral hygiene maintenance, easy−
repairs and long−lasting endurance of the appliance. It was also underlined, that when using this system the follow−
up visits are needed to prevent the abutments from increasing of occlusal overload (Dent. Med. Probl. 2007, 44,
4, 520–524).
Key words: telescopic anchors, clinical evaluation.
Streszczenie
W pracy autorzy dokonali oceny klinicznej zaczepów teleskopowych zastosowanych w celu poprawy utrzymania
dolnej protezy częściowej u jednej z pierwszych przyjętych do leczenia pacjentek. Opisali główne etapy
postępowania kliniczno−laboratoryjnego oraz metodę oceny stopnia retencji protezy na podłożu protetycznym.
W celu zakotwiczenia uzupełnienia wykorzystano korony stożkowe. Całość konstrukcji metalowej wykonano ze
stopu chromowo−kobaltowo−molibdenowego. Do olicowania teleskopów zewnętrznych użyto materiał kompozy−
towy. Na podstawie 8−letniej obserwacji autorzy stwierdzili, że system ma wiele zalet, które przemawiają za
celowością stosowania tych uzupełnień w lecznictwie protetycznym, szczególnie u osób starszych o ograniczonej
motoryce i słabym wzroku. W dyskusji poruszono problem retencji oraz wpływu tych protez na stan tkanek
przyzębia. Zadowalająca retencja i stabilizacja w czasie żucia pokarmu oraz działanie szynujące, a także dobra
dostępność dla zabiegów higienicznych, łatwość napraw i duża trwałość to główne cechy tego systemu. Zwrócono
także uwagę na konieczność prowadzenia leczenia następowego zapobiegającego powstawaniu przeciążeń
okluzyjnych w obrębie zębów filarowych (Dent. Med. Probl. 2007, 44, 4, 520–524).
Słowa kluczowe: zaczepy teleskopowe, obserwacje kliniczne.
Prosthetic treatment of the patients with resid−
ual dentition is a very complex process, because of
the difficulties connected with a choice of proper
method to apply. In this group of patients, the tis−
sue−supported, tooth−supported and tooth−and tis−
sue−supported removable dentures may be applied.
Tissue−supported removable dentures usually per−
formed in National Health Found (NFZ) – often
enable the insured patients only an inefficient mas−
tication, and, moreover, at the same time they gen−
erate an inflammation of periodontium and
increased mobility of abutments mainly caused by
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T. DĄBROWA, H. PANEK, P. NAPADŁEK
denture clasps. Additionally, intensive bone atro−
phy and dentures settling into gingival tissues
cause extrusion of the clinical crowns and subse−
quent occlusal disturbances [1–3]. Tooth−support−
ed and tooth and tissue−supported removable den−
tures are more comfortable, because part of the
occlusal forces is transmitted in physiological way
through the periodontium to the alveolar bone.
Removable dentures attached by means of tele−
scopic anchors are regarded to be a good clinical
solution [4–6]. This kind of restorations in patients
with reduced and residual dentition gives an
opportunity to reduce destructive rotational and
horizontal occlusal forces by directing them more
axially [7–11]. It can also increase the stability of
abutment teeth with periodontal disorders and pro−
tect them from pathologic migration, and, thus,
may enhance the functional effect of the prosthet−
ic treatment. The concept of telescopic crown
comes from optics, because it reminds the way of
the optical telescope works – movement of two
parallel cylinders. Telescopic crown is a system,
which consists of two elements: internal crown,
called male or primary crown and external crown,
called female or secondary crown. The primary
crown is cemented on the abutment and the sec−
ondary crown is attached to the removable denture
and has the shape similar to natural tooth. The tele−
scopic anchors have been applied in the
Department of Prosthodontics, Silesian Piasts
University of Medicine in Wrocław since 1997. In
this period 110 crowns in 24 patients were applied.
The aim of the study was a clinical assessment of
the telescopic anchors after eight−year wearing of
lower telescopic denture in one of the first patients
treated in our Department.
Case Report
Female patient, 72 years old, was referred to
our Department for prosthetic treatment. Clinical
examination revealed edentulous maxilla and eight
teeth present in the mandibula: #31, 32, 33, 34, 41,
42, 43, 44. Tooth #31, 32, 41, 42 had the third
degree of mobility in Entin’s scale. The patient
was using old upper complete denture, many times
repaired and had some painful complaints con−
nected with previously performed lower denture
(Fig. 1). After completing the clinical examination
a treatment plan was determined, which consisted
of making an upper complete denture and a lower
telescopic denture attached by means of conic
crowns. Before starting the prosthetic rehabilita−
tion, four anterior teeth in third degree of mobility
were extracted. On the first stage of prosthetic
treatment, the centric relation was registered and
the average angle of 6° for conical crowns was
determined using a diagnostic cast. On the next
clinical visit, anatomic impressions of upper and
lower jaw were taken and the preparation of lower
teeth #33, 34, 43, 44 was completed. Afterwards,
the compound impression was taken and the work−
ing cast with removable dies was performed in
order to fabricate the primary crowns. The cast pri−
mary crowns were tried in the patient mouth and
the functional impression of mandibula and maxil−
la was separately taken. Also the centric relation
was registered once again. The secondary frame−
work of the lower denture was performed in the
laboratory and the secondary crowns were
veneered with composite material Sinfony in
Rocatec (3M ESPE Seefeld Germany) system.
Afterwards, the artificial teeth were set−up in both
dentures and try−in visit was carried out. The inter−
nal prosthetic crowns were cemented on the abut−
ment teeth in the presence of ready−made upper
and lower removable dentures, inserted in place in
the patient mouth (Fig. 2). The control X−ray of
abutments area was made (Fig. 3a, b). The patient
was satisfied with the performed prosthetic reha−
Fig. 1. Intraoral picture. The status before a treatment
Ryc. 1. Zdjęcie wewnątrzustne. Stan przed rozpoczę−
ciem leczenia
Fig. 2. Extraoral picture. The status after a treatment
Ryc. 2. Zdjęcie zewnątrzustne. Stan po zakończonym
leczeniu
523
Telescopic Anchors in Removable Dentures
Fig. 3a, b. X−ray at the end of treatment
Ryc. 3a, b. Zdjęcie radiologiczne, stan po zakończo−
nym leczeniu
bilitation. Full adaptation to the lower denture was
noticed. Mastication abilities were increased.
According to the patient, new dentures enabled
consumption of hard nourishment in the contrary
to the old ones. With new dentures, a good aes−
thetic effect was achieved and no significant
increament of teeth mobility neither periodontitis
was noticed. The denture revealed the first degree
of retention according to Dabrowa’s scale [12].
This degree of denture retention was not changed
when it was estimated during follow−up visits per−
formed in three, six and twelve months.
Next visit took place after seven years since
completing the active phase of the prosthetic treat−
ment and it was caused by fracture of the abutment
tooth #34. This tooth damage was caused by bone
atrophy and root caries connected with no addi−
tional control visits and overall deterioration of
health state (Fig. 4). According to the patient opin−
ion, during eight years wearing of the lower den−
ture, she could easily masticate all kinds of food.
In spite of loss of one attachment the lower den−
ture had still a good retention. The clinical exami−
nation did not show any further damages to the
denture or veneering material. Denture hygiene
was good. A mobility of the abutments measured
with Periotest (Medizintechnik Gulden) system
scale was as follows: tooth #33 – 12 in ptv, tooth
#43 – 14, and tooth #44 – 17 ptv. The obtained
scores were the equivalent of first degree of teeth
mobility in Entin’s scale. The Periotest measure−
ments and control X−ray disclosed only minor atro−
phy of periodontium around the abutments (Fig.
5a, b). The external telescopic crown #34 was filled
with acrylic resin and the surface of root was cov−
ered with composite material. The lower denture
was relined and returned to the patient (Fig. 6).
Discussion
Double crowns system used by the authors of
this paper revealed a long−lasting usefulness in the
prosthetic treatment of the patient with reduced
dentition. Similar clinical observations were also
Fig. 4. Intraoral picture. The status after 8 years
Ryc. 4. Zdjęcie wewnątrzustne. Stan po 8 latach
Fig. 5a, b. X−ray of the abutments area after 8 years
Ryc. 5a, b. Zdjęcie radiologiczne okolicy zębów
filarowych, stan po 8 latach
Fig. 6. Dentures: lower after the reparation and upper
returned to the patient for further use
Ryc. 6. Protezy: dolna po przeprowadzonej naprawie
i górna, oddane do dalszego użytkowania pacjentowi
described in reports made by other authors [13, 14].
Telescopic crowns were presented in the dental lit−
erature at the beginning of XX century as an
example of attachments for removable telescopic
dentures. First telescopic crowns had primary and
secondary elements, which were bent, molded and
made from golden sheets. Low precision of this
kind of prosthetic restorations was causing a great
amount of failures.
In the contemporary literature, a great amount
of attention is now paid to the issue of retention of
the telescopic removable dentures. Retention of
524
T. DĄBROWA, H. PANEK, P. NAPADŁEK
these dentures is an essential factor which may
affect the time of their use Researchers have
described different possibilities of designs used to
regain the proper retention in the removable den−
tures. Ohkawa [15] carried out some research on
dependence between length of crown and conver−
gence angle of lateral walls. The obtained results
allowed the conclusion that the convergence angle
of internal crown walls has a greater influence on
removable denture’s retention than their length.
Retention is highly decreased with convergence
angle over 2°. Yasumasa [16] recommended the
enhancing of the retention by a golden pin situated
horizontally on the female attachment. It is acti−
vated when the retention of the removable denture
goes down. A different method was applied by
Minagi [17], who proposed to make undercuts
0.25 mm deep on the lateral surfaces of male
attachment. Specially prepared female attachment
has undercuts on lateral surfaces (angle 45°),
which may be activated when the retention forces
decrease from 9.8 N to 2 N. Such situation is usu−
ally needed after 10,000 cycles of retention of the
attachment. Another issue, widely described in lit−
erature, is an influence of telescopic dentures on
supporting tissues. Many authors observed posi−
tive results of prosthetic treatment with telescopic
dentures in patients with reduced dentition and
inflammation of periodontium. Hou and Tsai [18]
presented the results of their ten years−lasting
observations of the patients with periodontitis.
Telescopic anchors applied in treatment of these
patients had a positive influence on periodontal
tissues around the abutments. According to Kőrber
[19], the advantages of telescopic crowns are:
axial load of the tooth and full covering of the
abutment (on the contrary to clasps), which may
reduce tilting forces with their negative influence
on abutment supporting tissues. The axial forces
stimulate periodontal tissues and alveolar bone.
Positive opinion on influence of telescopic den−
tures on supporting tissues of abutments was pre−
sented also by Langer [20]. He described the
advantages of this restorations and their indirect
splinting influence, easy oral hygiene maintenance
and easy ways of repair.
The results of clinical studies carried out by
many researchers, as well as our clinical experi−
ences, induce to the conclusions that the telescopic
crowns have many advantages and should be espe−
cially recommended in prosthetic treatment of elder−
ly patients with reduced vision and motion abilities.
The main features of this system are: proper reten−
tion and stability of dentures during mastication,
splinting effect, good accessibility for repairs, easy
oral hygiene maintenance and durability.
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Address for correspondence:
Tomasz Dąbrowa
Department of Prosthodontics
Silesian Piasts University of Medicine
Krakowska 26
50−425 Wrocław
Poland
Tel.: + 48 71 784 02 90
E−mail: [email protected]