Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT06127576 |
| Other study ID # |
5895732 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
|
| First received |
|
| Last updated |
|
| Start date |
September 1, 2009 |
| Est. completion date |
October 1, 2023 |
Study information
| Verified date |
November 2023 |
| Source |
Federal University of Minas Gerais |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Observational
|
Clinical Trial Summary
Objective: The aim of this case series study is to present the rationality and scientific
evidence of a new design for a Double and Triple abutment with their specific new concept of
Biodynamic Optimized Peri-implant Tissue (BOPiT).
Methods: The innovative design of these abutments with a paraboloid geometry was based on
BOPiT, simultaneously involving the principles of mechanobiology, biotensegrity, and
mechanotransduction. Thus, individuals rehabilitated with different extents of edentulous
spaces using the innovative double and triple abutments on osseointegrated dental implants
are included in this case series. The double and triple abutments support 2 or 3 dental
crowns on a single implant, respectively. Clinic and radiographic examinations are presented
at T1 (loading after 4 months of the implant insertion surgeries with the appropriate
metalloceramic prostheses) and T2 [final examination with a follow-up time ≥ 3 to 12 years
(average of 7.2 years)].
Description:
Conception and design of the Double Abutment (DA) and Triple Abutment (TA): Scientific
Rationality Traditional abutments are generally cylindrical nowadays, having two curved edges
at the base and an edge that connects the two vertices on the side face (total of 3 edges)
considering its strength as a unit, while the new DA and TA features a paraboloid geometric
design along its entire length.
The paraboloid is a mathematical equation that generates quadric surfaces of two types:
elliptic and hyperbolic. The elliptic paraboloid is shaped like an oval-shaped cup and can
have a maximum or minimum point. In an appropriate coordinate system, with the three axes x,
y and z, it can be represented by the equation: z/c=x2 /a2 + y2 /b2, where a and b are
constants that determine the degree of curvature in the x-z and y-z planes, respectively (an
elliptic paraboloid opens upwards). The hyperbolic paraboloid, or hypar, is a doubly ruled
surface (composed of multiple lines, whose union forms the surface itself), usually
saddle-shaped. Its coordinated system is also based on three axes, manifested in the
equation: z/c = y2/b2 - x2/a2. For c>0, i.e., a hyperbolic paraboloid that opens downward
along the x-axis and along the y-axis (i.e., the parabola in the x=0 plane is open upward and
the parabola in the y=0 plane opens downward).
The design of DA (elliptical paraboloid) and TA (hyperbolic paraboloid) allows high stiffness
with reduced bending stresses and equalization of forces. Additionally, TA hyperbolic
paraboloid structures are the most complex and possess a unique combination of structural and
architectural properties, resultant from its double curvature, concave convex and suited to
carry the in-plane shear forces and transmit uniform eccentric axial forces to the other
members of the system. Vectorial loads are minimized, preventing the traditional axis of
transverse coordinates that imply early bone loss in the implant abutment connection area.
These designs represent the interaction that exists between all biological phenomena and
mathematics.
The new abutments are multiple mechanical load organizers, and support 2 (DA) or 3 (TA)
crowns on each abutment, with an innovative geometric design that is totally passive (no
welds), resulting from mathematical and physical conformations coupled in geometric vector
models.
DA and TA are protected by the following patents: "Pilar geminado sobre implante
osseointegrado e corretivo extensor compensatório de inclinações" [Double abutment on
osseointegrated implant and compensating inclination extensor corrector (PI BR 0505827-9)];
"Splint abutment over osseointegrated implant and compensatory slanted coping" (United States
Patent 9039416 and Canadian Patent No. 2,630,592); "System of triple abutments with connect
(United States Patent 11,701,206); "Sistema de pilares trigeminados e múltiplos sobre
implantes osseointegrados e guias direcionadores" [Triple and multiple abutments on
osseointegrated implants and guide directors (PI BR 0800298-3, Brazil)]. All patents belong
to the Institute of Technology and Research (Instituto de Tecnologia e Pesquisa -, Belo
Horizonte, Minas Gerais, Brazil).
Patients This clinical investigation was designed as a pre-post case series study and is
reported in accordance with the PROCESS (Preferred Reporting of Case Series in Surgery) and
Consensus-based Clinical Case Reporting Guideline Development. All procedures performed in
this study were in accordance with the ethical standards of the 1975 Declaration of Helsinki,
revised in 2013, and received approval from the Ethics Research Committee of the Federal
University of Minas Gerais, Brazil (CAEE: 60410222.2.0000.5149).
The selected group of participants were informed about the procedures and signed an informed
consent form before participating in the study. Patients were recruited from a private clinic
in the city of Belo Horizonte - Brazil (BR), between September 2009 and January 2019.
Participants were in good systemic health, non-diabetic and non-smokers. Prior to dental
implant insertion surgeries, pre-surgical evaluation, detailed oral examination including
complete periodontal examination, dental biofilm control and coronary polishing, as well as
scaling and root planning and treatment of carious lesions (when necessary) were performed.
Since these new abutments break important paradigms in implant dentistry, such as passive
multiple prostheses supported on a single implant with biomechanical benefits, the
investigators have cautiously chosen to perform only ~5 cases/year, aiming at reaching a
minimum follow-up time of 5 years.
This consecutive case series comprises a sample of 37 individuals/43 cases (16 men and 21
women) with different extensions of edentulous spaces rehabilitated using DA (n=28) and TA
(n=15) in 43 osseointegrated implants. All cases using DA and TA had occlusal function with
their respective antagonistic pairs (natural, restored or implanted teeth). Radiographic
exams (analogue or digital) are presented at T1 (loading after 4 months of implant insertion
surgeries with the appropriate metal-ceramic prostheses) and at T2 (final exam) with an
average follow-up time of 7.2 years (>3 to 12 years).
The implants were cylindrical with internal hexagon and without surface treatment, presenting
4.0 mm in diameter and length varying between 10 and 13 mm (Neodent® - Grupo Straumann,
Curitiba, Paraná, Brazil).
Clinical and laboratorial procedures
(a) Selection of components for molding: analogues, transfers and Universal Cast to Long
Abutment (UCLA) with metallic base in cobalt chromium compatible with the diameters and type
of hexagon of the implant system platforms installed (all cases in this study being with
internal hexagon); (b) molding of the osseointegrated implant using a compatible transfer and
antagonists; (c) Confection of the manual work model; (d) use of UCLA with metallic base to
adapt the design of DA or TA in acrylic, with individualized design according to the
measurements and paraboloid surfaces of the DA (elliptical) and TA (hyperbolic). The use of
angulation in DA and TA is individualized, versatile and dependent on the position of the
implant, when necessary; (d) casting the pillars in cobalt chromium alloy and polishing.; (e)
Confection of crowns according to the chosen material (porcelain or resins) and (f) the DA or
TA abutments are screwed into the mouth and the crowns cemented. All laboratorial procedures
were performed in one single dental laboratory.
