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ADVANTAGES AND DISADVANTAGES OF CEMENT- AND SCREW-
RETAINED IMPLANT SUPPORTED PROSTHESIS
Nematillaeva Z., Irisboeva F. group № 303 Dentistry faculty.
Supervisor: Kim V.
Tashkent state dental Institute, Uzbekistan.
Relevance.
Implant-supported fixed dental prostheses (FDP) represent a well-
established treatment option that has evolved to become a standard of care in dental
medicine over the past four decades. This success is based on the phenomenon of
osseointegration, which has been enhanced through progress in surface technology,
refined surgical techniques, the improvement of the stability of interfaces between the
implants, abutments and dental prosthesis, as well as the establishment of lifelong
prophylactic efforts to prevent biologic complications and failures. The main focus in
prosthetic research is now the development of materials with better biomechanical
characteristics to fix the suprastructures with the prosthesis.
Purpose of the study.
It explicitly reviews the studies concerning cement- and
screw-retained implant supported prosthesis to determine the efficiency of the two.
Materials and methods.
Rola Shadid, BDS, investigated and contrasted the
usage of screw and cement connections of the prosthesis and implant in clinic practice
in 2014, because both approaches have benefits and drawbacks in the clinic. Clinical
experience, frequency of usage, and the structure of the faults in crown-to-implant
cemented and screw connections are not systematized. Screw-retained connection
provides a rigid connection of the prosthetic construction with the implant or
abutment. Cement fixation allows you to bypass some limitations. These include:
aesthetics, low occlusion stability, the complexity of manufacturing restorations with
a passive fit.
According to the authors, the cement layer absorbs extra occlusion load and
distributes it evenly to the implant and bone. In terms of manufacturing process,
prosthodontic constructions on implants with cement fixation are similar to other
prosthodontic constructions. As a result, the dental laboratory technician does not
require any more training. Cement connection is cheaper than screw fixation because
the devices and materials utilized are less expensive. It is easy to make a cement-
retained repair when the implant axes diverge by more than 17°, because no angled
screw-retained abutments exist in any system with a screw lead divergence of more
than 17°.
If screw fixation is still required in this case, an individual abutment has to be
created, which demands extreme precision and competence. Plastic deformations
occur in the cervical zone of the implant and screws (abutment or transocclusal)
regardless of the method of crown fixation, as well as in cement during cement
connection in the metal-ceramic frame. The manufacturing of implant restorations
requires a high level of precision in several clinical and laboratory procedures. Small
errors at any stage of the production process add up to a major distortion of the
restoration parameters.
The final restoration changes as a result of adding up all the variances that
occurred during the manufacturing process. When the sum of all deformations equals
zero, we have an ideal passive fit. The UCLA abutment was examined by Lewis SG,
© TOSHKENT БАУЕАУ STOMАTOLOGIYA INSTITUTI “YOSH бЕШЕАИ KUNLАRI” 2022
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Lamas D, and Avera S, who discovered that after treating 46 patients with 118 UCLA
abutments, 4-year success rates were 95.8%. Gold and titanium are the most common
screws. The frictional resistance that develops between the internal thread of the
implant and the connecting screw causes retention.
A screw connection is an assembly in which two elements are attached together
with a screw. If the external forces attempt to separate the parts are greater than the
force holding them together, the screw will loosen. Separating forces are the forces
that strive to detach the pieces. The retention of the implant screw stiffness is
influenced by two key aspects. This is a decrease or minimization of the joint-
separating forces applied to dental implants, as well as an increase in the fixing
pressure or forces. In a clinical setting, it is unlikely that several implant prostheses
can be connected with a completely passive fit. Micro-vias are created as a result of
these mismatches, and an accurate interface between the casting and the implant is not
obtained. The goal is to keep clinically acceptable separation forces to a minimum.
The first step in retaining firm implant screws is accurate implant placement and
treatment planning.
Results and discussion.
Screw retention may be recommended:
-to avoid an additional risk factor with the use of cement and a possible cement
remnant; -in the aesthetic zone, for provisionalization of implants to enable soft tissue
conditioning and finalization of the emergence and mucosal profile; -when
retrievability is desired; -Implants must be placed in a prosthetically ideal position
with the future access hole of the planned crown below the planned incisal edge in
order to facilitate screw retention.
Cement retention may be recommended
-for short-span prostheses with margins at or above the mucosa level
-to compensate for improperly inclined implants
-for cases where an easier control of occlusion without an access hole is desired
- for example, with narrow-diameter crowns
-The cementation procedure should be carried out with great caution, with the
FDP margins placed at or above the tissue level.
Conclusion.
The limitations and benefits of cement and screw attachments in
implant prosthesis are demonstrated. Knowing the benefits and drawbacks of cement-
and screw-retained prosthesis will assist the dentist in determining the best solution
for each clinical case.
Bibliography:
1. Нигматов, Р., Муртазаев, С., Арипова, Г., Шаамухамедова, Ф.,
Рузметова, И., & Юлдашев, О. (2015). Разработка тактики лечения при случаях
редкой врожденной олигодентии. Stomatologiya, 1(1-2 (59-60)), 143-147.
2. Bardyshev, I. I., A. S. Degtyarenko, and T. I. Pekhk. "8, 13-Epoxylabd-14-
en-19-oic acid—A component of the needles ofPinus sylvestris." Chemistry of
Natural Compounds 18.4 (1982): 447-449.
3. Клёмин, В., Нигматов, Р., Кубаренко, В., Глинкин, В., & Ирсалиев, Х.
(2016). Условно-несъёмные зубные протезы. Stomatologiya, 1(2-3 (63-64)), 36-42.
