clinical uses of dental implant

Indications
Dyna Implant System can be used in the following clinical
situations:
 Retention of overdentures in the maxilla or the mandible.
 Restoring shortened maxillary or mandibular arch with fixed
constructions (with possible connection with natural
elements).
 Restoring edentulous patients with fixed constructions.
 Restoring edentulous patients with fixed-detachable
prostheses.
 Retention of maxillo-facial prostheses.
Octalock System was developed primarily for enhancing construction of the crown and
bridge works. Therefore, it is additionally indicated for:
 Restoring single missing teeth.

Contraindications

The Dyna System is a multipurpose implant system allowing
for easy construction of different prostheses. Simplicity of use, however,
can be often seen as a universal solution to all kinds of prosthetic
problems. Such an approach may lead to failures. These, are not
connected with the system.*
When using any implant system following contraindications
should be taken into consideration:
1 local
-local infections
-inadequate quality or quantity of bone in place of implantation
-inadequate hygiene
-unfavourable bite relation
-mucosa infections
-jaw defects
-macroglossia
2 systemic
-systemic diseases of bone, endocrine system, homeopoetic system
-rheumatic disease
-cardiac disease
-nephritises or nephroses
-cirrhosis hepatis
-psychic diseases
-defective immune response
-allergic diseases
3 age related limitations
-children
-juvenile patients with not finished growth of maxillo-facial bones
-elderly patients with:
-insufficient bone quantity or quality
-unfavourable morphological conditions
-difficult bite relation
-trauma of the mandible or the maxilla
-lack of motivation
4 other
-pregnancy
-planned radiotherapy
-drugs and tobacco abuse
-inability to perform adequate surgery operation
-diseases treated with large doses of steroids
-limited mouth opening
-lack of motivation to perform adequate hygiene
Most of the contradictions listed above are now viewed more as conditional and temporary
rather then absolute.
1601-01.04 Dyna Pushin Implant Manual GB 66 / 144
The following contraindications for the Dyna Implant System should be taken into consideration:
-placing the Dyna implant directly after extraction
-using 3.0mm implants for fixed constructions subjected to heavy or moderate loads;
-constructing cantilevers
-joining implants with natural elements.
In most cases, it is the severity of the condition and the patient’s residual ability to tolerate
treatment that determine whether or not implant therapy is contraindicated.
In addition, there are a number of systemic medical conditions that can cause complications
during the postoperative healing stage, and may contribute to implant failure.
These factors must also be assessed by the implant surgeon.
Dyna Dental Engineering disclaims any reliability for failures subject to
contraindications that have not been aforementioned but which are described in the
world literature. Therefore, we recommend careful study of adequate available
research material.

Planning

Planning is one of the most important factors in
successful rehabilitation of edentulous or partially
edentulous patients with dental implants. Full success
depends on a balanced judgment of patient’s expectations
on the one hand, and surgical and prosthetic possibilities on
the other.
This manual provides a framework of concepts and ideas to
facilitate the evaluation of prospective implant patients.
The information presented should also help to promote
successful planning and co-ordination of treatment for the
implant restored patients

Principles of patient selection
Preliminary evaluation
The evaluation of a patient as a suitable candidate for implants should follow the same basic
format as the standard patient evaluation, although some areas require additional emphasis and
attention. In particular, the patient’s medical history may reveal a number of conditions that could
complicate or even contra-indicate implant therapy.
The following aspects are relevant when examining a patient as a prospective recipient of dental
implants:
1 initial consultation;
Prior to any medical examination, or local conditions evaluating, patient should clearly formulate:
 his problems with existing prosthesis or dentition (aesthetic, lack of stability, lack of
retention etc)
 wishes and expectations in respect to the future restoration.
Dentist on his side should explain:
 existing treatment possibilities
 benefits and risk of implants
2 medical examination
 general health situation (current and past)
Patient should be physically and mentally healthy. Patients age is less important though it
should not be underestimated. Implantation in an early age is per se not a real
contraindication. Contrary, young patients have a bigger chance for successful
osteointegration. However, because of the fact that the bone growth with those patients is
still an active process, and the connection between the implant and the bone has ancylotic
type, the chances are, that the potential operator will be confronted with unfavourable
prosthetic situations after biological maturation of such patients. Namely implanted
fixture and surrounding it bone (which could not grow) will be somewhat “deeper” than
the rest of the dentition (e.g. adversely influencing the emergency profile of the
restoration).
On the other hand elderly patients having matured bones may present contrary process –
bone resorption, making it difficult to find favourable position for implants. Additionally,
all factors that may interfere with good implant healing and functioning (see
contraindications) should be noted.
Contraindications presented above are generalized and valid for every surgery. It
does not mean, however, that for instance patients who smoke can not have implants.
They do, but the risk of implant failure is much higher. Similar is valid for the rest.
Therefore, it is very important to discuss the problems with the patient before the
operation and explain to him everything in detail.
1601-01.04 Dyna Pushin Implant Manual GB 68 / 144
 specialist care
In cases where the patient is under the specialist care it is strongly recommended to
consult him, even if the cause of this care seems to have no direct connection with implant
treatment.
 medical and social history
3 local conditions evaluation
 effective oral hygiene and motivation to perform such
 local diseases (bruxism, periodontal problems, allergy etc)
 quality and thickness of mucosa
 intermaxillary relations
 bone quantity and quality
4 general aspects
 patient’s habits: smoking, diet, drugs abuse etc
 finding local and systemic contraindications
 evaluation of potential implant sites
5 psychic status
Even if a patient is found to be a suitable candidate for implant therapy, he or she must be
apprised of two additional factors before being considered for treatment:
 Patients receiving implant therapy for a mandibular bar over-denture may potentially
experience approximately four to six months of discomfort and diminished function
before any benefits become apparent. They are frequently required to go without their
removable prosthesis for significant periods of time following initial surgery.
 Implant failures can occur at any time, despite everyone’s best efforts. Current success
rates in the anterior mandible are very high. However, even here, implant fixtures can
and do fail.
If the patient cannot come to terms with the possibility of failure, or four to six months of
potential discomfort and inconvenience, then he or she is not a suitable candidate for implant
therapy.
1601-01.04 Dyna Pushin Implant Manual GB 69 / 144
Pre-operative planning
Before selecting the most suitable type of implant restoration, the practitioner should
review and be guided by the patient’s previous dental history. It is also vital to evaluate the
patient’s chief complaint, as it may have an equal bearing on treatment outcome.
1 surgical criteria
Proper length and diameter selection of implants is crucial for their uneventful placement
and functioning. The definitive site should be carefully chosen bearing in mind optimal support
of prosthetic construction and load distribution. As a general rule implants should be surrounded
at least by 1mm of the bone from each side. However, in order to prevent bone resorption
between implants or implants and natural elements following minimal distances should be kept:
implant – implant - 3mm
implant – tooth - 2mm
The violation of the sinus maxillaris, canalis mandibularis or the mandible itself, should be
avoided (2mm of bone are advisable between those structures and implants!).
The design of final prosthetics should be considered prior to implant surgery. CT scans,
radiographs, study casts, wax-ups an overall clinical evaluation should be utilized to determine
the optimal position and angulation of all implants at the time of placement. Drilling guides (or
surgical stents), particularly in case of fixed constructions, are strongly recommended. Total case
planning including eventual prosthetic-restorative modalities is essential for proper use of Dyna
Implant Design.
To help choosing the proper implant size and implantation site the following planning
steps are important:
Intraoral inspection
Intraoral inspection and palpation of mucosa is the first step to give general information
about anatomical situation, available bone, muscles and fraenula attachments. In many
cases it can correct our first impression that bony conditions are favourable.
Jaws relation should be noticed.
Looking at the edentulous mandible over time, it loses height and width of bone. As this
occurs, the width of attached gingiva narrows considerably, the tongue increases in size
and activity, and the buccinator and mylohyoid muscles become more active. In addition,
the genial tubercles become more prominent and in the severely resorbed mandible, they
can often be superior to the height of the ridge crest.
With successive denture treatments, it is common for the vertical dimension of occlusion
to decrease as bone resorbs. This promotes an increased tendency toward a skeletal Class
III relationship.
Posteriorly, poor ridge height inadequate attached gingiva, and compromised ridge shape
cause increased horizontal movement of the prosthesis. This increases the lateral forces
that are brought to bear on the anterior implants, and may affect overdentures retained on
implants in the anterior part.
It is also important to notice the dentition. For example: a full natural arch in
some situations can be contraindicated for placing fixed construction in the
opposing jaw whereas, full denture seems to have no influence on this type of
prosthetic construction. Given the fact that occlusal forces in the molar region
1601-01.04 Dyna Pushin Implant Manual GB 70 / 144
are in the range of 150 to 250 psi, and knowing that parafunctions increase
these occlusal forces to as high as 900 psi it is clear why it is so important to
assess the situation properly, though in the edentulous patient, the average
occlusal force drops to just 50 psi.
Natural dentition opposing implants is always a situation of special
consideration. In those cases the load forces transferred onto the implants will
be greater and a small fault in prosthetics (allowing for perfect planning and
following surgery) may lead to serious consequences including implant failure.
Maximum occlusal forces in such situations may increase as much as 300 per
cent compared with pre-treatment values.
X-ray examination
X-ray photos help to get more adequate information about anatomical situation
and the position of important structures. Different radiographic techniques are
available.
The most accurate is Computer Tomogram scanning (CT). This technique
gives exact information about position of the sinus maxillaris, canalis
mandibularis, vertical horizontal and transversal dimensions of available bone.
An orthopanthomogram (OPG) is a very popular and frequently used
technique. However, it is not as precise as CT scans and it can only supply
information about vertical and horizontal dimensions of the bone. To avoid
faults in measurements (connected with size deformation usually in scale
1:1,20; 1:1,25) OPG can be taken with special templates that patient wears in
the mouth during taking the X-ray. By placing round, metal markers over
potential implant sites in those templates we can calculate (knowing their
dimensions) the real height of the bone.
Another way of choosing the implant size is placing a special X-ray tracing
over the OPG. It is a fast method but not fully accurate. Therefore, to make
the procedure safer Dyna Dental Engineering produces it in scale 1:1,3.
Models analysing
By analysing study models of the patient one can determine intermaxillary
relations as well as bone configuration. The same models can be used to
visualize bone in so called bone mapping technique. This technique allows to
transfer the thickness of the mucosa to be transfer onto the model and in this
way gain information about the transversal shape of the bone.
Different methods of measuring the thickness of the gingiva are available.
The simplest is to use a thin needle or endodontic instrument with endostopper
to punch gingiva in the place of potential implantation on different
levels and then transfer measurements to the anatomical model. More
advanced is using an ultrasonic instruments which measures the thickness
automatically.
Diagnostic set-up in wax.
To provide information about favourable angulation and positioning of
implants diagnostic set-ups can be used. The angle between the long axis of
the implant and the direction of bite load should be as low as possible and not
bigger than 15o .
Furthermore set-ups can be used to produce a drilling guide. After
consultation with your technician concerning the type of desired prosthesis,
1601-01.04 Dyna Pushin Implant Manual GB 71 / 144
location and number of implants, insert angulation an acrylic or metal stent
can be produced (type of it depends on personal preferences of the operator).
This stent serves as a drilling guide and is used intra-operatively. This
solution seems to be especially useful for less experienced operators who may
find preparing parallel implant beds problematic. It has also another
advantage. Relations between neighbouring implants as well as between
implants and natural elements are decided before the operation and chosen so
that the best esthetical effect can be achieved.
2 prosthetic criteria
The type and design of prosthetic construction should be determined before
implantation. X-rays, models, wax set-ups may be useful to determine implant
position and angulation. It is also possible to use earlier prepared drilling guides.
Total case planning including surgical and prosthetic planning is indispensable for
proper use of Dyna Implant Design.
 It is recommended for overdentures in the mandible, 2 to 4 implants to be placed
between foramina mentalae .. In the maxilla 4 to 6 should be placed remembering
about position of the sinus maxillaris. Eventual sinus lifting may be considered.
For fixed bridges in edentulous patients minimum of 6 implants, and preferably 8,
must be used. The diameter of the used implants for fixed (single crowns, bridges
also with memory), and bar constructions should be at least 3,6mm, and the length
at least 10mm.
 In relation to the diameter of used abutments the sufficient distance between
neighbouring implants should be kept in order to achieve satisfactory aesthetics.
Implants placed too close to one another or neighbouring teeth may be a serous
problem during prosthetic reconstruction. Using drilling guides during surgery
and choosing proper implant diameter prevents such problems.
 In relation to prosthetic design rules of biomechanics should be taken into
consideration. In order to minimize excessive compressive/transverse forces
coming on the final restoration, to reduce off-axis loads, reduce occlusal tables by
one third. Create shallow incline planes to change the direction of unfavourable
forces. Avoid creating cantilevers as they multiply the forces due to moment arm.
Group function occlusal scheme is recommended and the centric occlusion
contacts should be light. Night guards for bruxers, clenchers or heavy biters is
strongly recommended.

To determine the ideal diameter and place for
implants use the study models. Implants
should be chosen so that the minimal distance
between an implant and a tooth (A, C) should
be at least 2mm, whereas between two
neighbouring implants(B) 3mm. Buccolingual,
and mesio-distal position must be
chosen in relation to the shape and position of
natural teeth.

MEMORY AND FIXED ABUTMENTS

The Cawood and Howell classification.

The importance of preparing the accurate treatment plan for successful implant
restoration is unquestionable. The aim of the modern implantology is to prevent, or delay bone
mass loss in edentulous and partially edentulous ridges and restore the function of the
stomatognathic apparatus. Resorption of the alveolar ridge after tooth extraction is a continuing
process and manifests itself by anatomic changes that occur in a vertical as well as a horizontal
plane.
It is very important to the practitioner to realise what changes the edentulous ridge may undergo.
Different classification has been proposed to divide edentulous jaws but the most popular at the
moment seems to be the classification of Cawood and Howell. It gives the operator a chance to
visualise different forms of the ridge and set indications for e.g. the type, number or length of the
implants. It may be used to provide guidelines for the use of implants in the prevention of bone
loss, and function restoration in the edentulous jaws.
However, our idea of using this classification was to make the cooperation between the surgeon
and the prosthetist easier by setting clear indications for particular prosthetic solutions in
connection with the form of the ridge. When referring the patient to the surgeon it can become
extremely useful tool in establishing mutual cooperation.
Cawood and Howell classified edentulous jaws according to a three-dimensional analysis of the
anatomy. Three different cross sections were used:
 in the symphysis region,
 through the mental foramen
 in the molar region.
They found the following dependences:
- the alveolar ridge resorbs in the anterior and premolar regions horizontally as well as in
vertically
-the resorption process was almost entirely confined to the alveolar ridge of the mandible
and that
-the basal part, which is the part caudal to the mental spina, does not significantly change
after extraction.

Cawood and Howell proposed the following resorption stages:
Class I. Dentate ridge.
Class II. Ridge directly after extraction.
Class III. Broad and rounded ridge with adequate height and width.
Class IV. Knife-edge ridge with sufficient height but insufficient width.
Class V Flat ridge with insufficient height and width.
Class VI. Depressed ridge with a cup-shaped surface.
Additionally two classes are added:
Class VII, the labial part at the site of the symphysis has been resorbed in a vertical direction to a
height of 10 mm,
Class VIII, a further reduction of the height to a value of 5 mm.