Scientifica implantology

Numeri Uno, 5: 8-14, 2009

PROSTHETIC REHABILITATION ON TEETH AND IMPLANTS USING SURGICAL PROCEDURES OF CRESTAL EXPANSION AND SINUS LIFT AND PROSTHETICALLY-GUIDED SURGERY

The change in the prosthetic solution from a fi xed prosthesis on natural teeth to fi xed prosthesis on implants has placed new emphasis on the treatment of post-extraction wounds. Preserving the alveolar bone volume after an extraction makes the subsequent insertion of the implants easier and improves the functional and aesthetic result of the prosthesis, even in sites where the pontics are lodged. The techniques for expanding the bone crest, therefore, are not only suitable for allowing implants with a standard diameter to be inserted in otherwise very slim crests, but are also suitable for correcting anatomical situations next to intermediate elements of the prosthesis, such to improve the aesthetics, function and hygiene.
The management of the provisional phase has become very important both before the implant surgery (to help preserve the volume and the forms of the soft tissues) and at the time of placing the temporary prosthesis on the implant.
In fact, a temporary prosthesis with suitable contours allows “conditioning” the management of the tissues, especially at the level of the intermediate elements, simulating the cervical contour of a natural tooth as much as possible.

Numeri Uno, 2014; 20: 20-21

REHABILITATION OF A SINGLE ELEMENT IN POSITION 4.6 WITH A PRAMA IMPLANT

This case report presents a clinical result obtained with a new implant morphology. The characteristics of this new implant system make it different from others, due above all to the distinctly extracrestal positioning of the abutment-implant connection and the morphology of the abutment-implant complex neck with a vertical finish area.
The transgingival healing of the implant allows a second surgical operation to uncover the implant to be avoided.
The peri-implant mucosa tissues heal around the machined titanium surface of the implant neck. These tissues no longer need to be stimulated during the various prosthetic phases, making it possible to eliminate some of the modifications to the bone margin caused by repeated screwing and unscrewing operations for prosthetic components.
In addition, by moving the implant-abutment gap away from the marginal bone crest, the peri-implant bone resorption that always occurs in implant methods where this gap is at the level of the bone margin is eliminated.
The vertical finish area of the abutment-implant neck complex allows the emergence morphology of the prosthetic crown to be used to guide the soft tissues and to adapt them to its anatomy. Furthermore, the ferrule effect that can be obtained by covering not only the abutment but also the implant neck with the prosthetic crown could reduce the possibility of biomechanical complications like the slackening or breakage of the post screw.
The clinical result appeared to be positive, both in functional terms and with respect to the integration of the prosthetic crown with the surrounding tissues.

Numeri Uno, 2014;20:18-19

REHABILITATION OF A SINGLE ELEMENT IN AN AESTHETIC AREA WITH A PRAMA IMPLANT

Implant rehabilitations in aesthetic areas always require the greatest care by clinicians, particularly in cases where a post-extraction implant technique is necessary, and even more so in case of immediate loading. In these cases, the preparation of the clinical case is of fundamental importance to allow as much pre-operative information as possible to be obtained, and so that the materials to be used can be studied. In the case described here, it was necessary to use a screwed-in implant that would allow an insertion torque of no less than 50 Ncm to be reached, and that at the same time would give us the possibility to vary the emergence point of the prosthetic profile. allowing us to perform vertical Platform Switching and giving the operator. The PRAMA implant used combines these main characteristics, and also adds surfaces with a high level of biological performance.
Clinical procedures were complicated by the need to perform guided bone regeneration in the vestibular dehiscence as well, requiring particularly accurate soft tissue management, in line with the indications provided in literature for aesthetic cases.
In addition, the temporary crown was supported in the initial phases by a small splint connected to nearby teeth with composite resins.

Date of procedure 28-02-2014
Data of definitive prosthetization 28-7-2014
Photo and check-up X-ray 13-5-2015

Numeri Uno 2014; 01:6-9

RELIABLE IMPRESSION TECHNIQUES: TWO PROPOSALS FOR THE SAME OBJECTIVE

A patient of 45 years, with no medical history of interest, with a totally edentulous mandible. After the clinical and radiographic study, it was decided to plan the insertion of 6 lower implants and the fitting of an temporary immediate screw-retained prosthesis.
After the standard surgical procedure, which consisted in the insertion of 6 Sweden & Martina Premium implants, 3.8 mm x 13 mm, the transgingival healing posts were positioned, with sutures around them. The transgingival posts were later replaced with PEEK transfers, which were then stabilized with a photopolymerizing resin (Conlight, Kuss Dental, Madrid, Spain). The models made previously were subsequently modified to allow them to enclose the fixed structure obtained, then taking an occlusion impression that would give the laboratory technician information on occlusion before the operation. The interior of the model was filled with a polymer (Impregum, 3M ESPE, Seefeld, Germany) and a closed-mouth impression was taken, positioning a material for registration on the occlusal faces of the teeth (Occlufast, Zhermack, Italy). After the polymerization time (3 minutes), the impression was removed and sent to the laboratory to allow the temporary prosthesis to be made.
Three months later, final rehabilitation was commenced, envisaging a hybrid screw-retained CAD/CAM prosthesis with a titanium structure.
The final impression was made using transfers with an open tray fixed with a 1.5 mm titanium bar. This procedure was completed using the Dent Weld intraoral welding machine. This device has a handpiece with forceps that transmits energy capable of generating the heat necessary to melt titanium.
Before starting the protocol, an OptraGate retractor (Ivoclar Vivadent, Schaan, Liechtenstein) was used to facilitate the opening of the patient’s mouth and improve access to the transfers. The Dent Weld device was then configured with the Single programme with a selected power value (54% at 162 joules for a titanium bar thickness 1.5 mm), and the electrodes were connected to the two transfers. The bar was cut with a diamond milling blade at right angles and irrigation, and the procedure continued on the subsequent transfer with a new welding bar. In this way it was possible to avoid the “memory effect” of the titanium bar, which could produce a distortion of the assembled transfers on detachment of the impression.
After all the transfers had been fixed two-by-two, the correct positioning of the custom-made tray was verified. The impression was then taken with the closed-tray technique, using a double mixture of light and heavy silicone (Virtual, Ivoclar, Schaan, Liechtenstein).

Numeri Uno 2014;18:12-14

CHAIRSIDE ELECTRICALLY-WELDED CONOMETRIC IMPLANTOPROSTHESIS WITH IMMEDIATE LOADING ? A CLINICAL CASE

The patient presented with the need to rehabilitate third quadrant in the region of elements 35 and 36, following the avulsion of element 36, seriously compromised. At the patient’s request, we did not proceed with the immediate post-extraction insertion of the implants, but opted instead for deferred insertion. Four 4 months after extraction we therefore used the flapless technique to insert two Shelta implants (Sweden & Martina), respectively of diameter 3.80 mm and length 11.5 mm at position 35 and diameter 4.25 mm and length 11.5 mm at position 36. On both implants an insertion torque of 65 Ncm was used. Two final conical posts with reduced diameter were positioned on the implants, for use with the conometric prosthetic system (Sweden & Martina). In the same surgical phase the preformed conometric caps were positioned (Sweden & Martina). The caps were fixed by intraoral welding (Dent Weld, Sweden & Martina), using a titanium bar with diameter 1.5 mm. The result was an extremely precise removable prosthesis that allowed us to make a temporary prosthesis for immediate loading.
The welded caps were removed to check their passivity and to verify that they could be incorporated into the prefabricated temporary prosthesis. After the electrically-welded structure was repositioned on the posts, the temporary prosthesis was directly relined, so as to be able to incorporate the structure itself to obtain a reinforced removable prosthesis that would also have the advantage of stabilizing the implants.
Conclusions: The case presented shows that with this technique an implantoprosthesis for immediate loading that respects the concepts of platform switching can be made quickly and easily, positioning the final post that will remain in place in the surgical phase, thanks to the availability of posts with different transgingival heights. The use of prefabricated conometric caps allows a very high level of precision to be obtained, and fixing with electric welding makes it possible to stabilize the inserted implants and to proceed with the chairside construction of a temporary prosthesis that is not only extremely resistant, but that can also be easily removed by the dentist at any time. The standardization of the method and its adaptability to the various Sweden & Martina implant systems the reasons for its ease of use and consequent inexpensiveness.

Italian Dental Journal 2014; 29, agosto

CONOMETRIC TECHNIQUE WITH AN ELECTRICALLY WELDED TEMPORARY PROSTHESIS FOR IMMEDIATE LOADING

In both these articles, Dr. Panadero describes cases treated with a new technique of prosthetic rehabilitation, using an overdenture with a secondary structure anchored by means of horizontal insertion to a primary structure. This solution makes it possible to the recover the horizontal dimension, avoiding the need to resort to invasive reconstruction operations.

Journal of Oral Implantology 2014; 8 [Epub ahead of print]

In both these articles, Dr. Panadero describes cases treated with a new technique of prosthetic rehabilitation, using an overdenture with a secondary structure anchored by means of horizontal insertion to a primary structure. This solution makes it possible to the recover the horizontal dimension, avoiding the need to resort to invasive reconstruction operations.

Numeri Uno, 2013; 17:18-20

DIRECT PROSTHETIC FRAMEWORK (D.P.F.)

The accomplishment of an implant rehabilitation with immediate loading is a challenge for the dental team, and success is linked to the synergy between the surgical and prosthetic phases.
A case report describes a simple technique for the production of a temporary full arch with immediate loading. The use of new elements specifically designed for the production of a castable resin framework and intraoral cementation of the metallic truss make it possible to reduce insertion times for the temporary post to 8 hours after the end of surgery, obtaining the necessary requirements of strength and passivity that are so important during the initial phase of implant loading.

Numeri Uno, 2015; 04: 16-19

GUIDED SURGERY WITH IMMEDIATE LOADING: IS IT A PREDICTABLE TECHNIQUE? A CLINICAL CASE

Male edentulous patient aged 35 years, classification ASA type I, for maxilla rehabilitation with 8 Outlink2 implants with external connection (Sweden & Marina), using guided surgery with bone support and immediate loading. Simplant® software was used for the treatment plan and the production of a stereolithographed surgical guide.
A photographic study was made, including extra-oral photographs for the median facial line, parallelism between the bipupillary line and the intercommissural line, analysis of the facial thirds, type of profile and vertical dimension.
The preliminary impressions were taken with irreversible hydrocolloids (aligned) to obtain master study models. The facial arch and the intermaxillary registers were determined, for mounting in the articulator.
The basic structure was prepared with wax, then carrying out a trial of the teeth for the fixed prosthesis, on which the radiological-surgical guide would be based.
A CAT scan was made with a duplicate guide in the patient’s mouth. A preliminary study was then made by computer for the ideal position of the prosthesis on the dental implants.
This transfer of the position of the implants stabilized in the pre-surgical phase made it possible to develop the prosthesis for immediate loading in advance.
After assessing the clinical conditions of the study, the type of surgical guide most suitable for the patient was chosen, on the basis of bone support.

The radiographic study was used:

• To make the CAT scan after occlusion was tested with the duplicate of the radiographic guide, as explained earlier.
• To reconstruct the CAT scan images using the specific software for this surgical procedure.
• To determine the ideal site for the positioning of the implants according to the available bone, the final prosthesis and the anatomical structures.

The patient presented at our surgery after the study had been completed using the software, with both the radiographic and the clinical data. All information was sent to the technical centre for preparation and return of the surgical guide before surgery.
A total-thickness flap was first raised, fixing the stereolithographed surgical guide with two lateral pins and with surgical implants in each arch. A posterior milling protocol was performed through the guide, which was oriented on the inclination/angle of the alveolus.
The immediate prosthesis was then produced. The immediate prosthesis was adapted in the same surgical phase with an acrylic eggshell temporary, which had been made previously in the articulator above the temporary anti-rotation posts, according to the position of the planned implants.
The acrylic temporary had perforations for the exits of the fixation screws of the temporary posts, to avoid escape of the self-polymerizing acrylic during relining, and to obtain a fixed but removable prosthesis. After hardening, excess material was removed from the model. Finally, it was screwed onto the posts again and sealed with cotton and acrylic.

The use of guided stereolithographed surgical guides represent a step forward in oral implantology. With meticulous planning and appropriate software, predictable results can be obtained due to the study performed, but at a more expensive cost than with conventional methods.
The technique described requires long-term research and improvements to the fixing points for ferrules.

Numeri Uno, 2013;16:12-13

ECHOPLAN: ACCURACY OF GUIDED IMPLANTOLOGY

Guided implantology offers a new method of performing surgical operations based on planning.
Software applications process DICOM images from the cone beam, giving a 3D rendering in which the implant can be inserted virtually. The production of a surgical guide makes it possible to transfer project information for the operation, which thanks to the engineering of the Sweden & Martina EchoPlan kit becomes easier to perform for the implantologist, with greater comfort for the patient and greater insertion precision. Guided implantology is the door that gives access to new methods for planning implantology and prostheses. Digital techniques reduce time and costs, and increases predictability and the coherence between theory and practice.
Case discussion: the operation was carried out by cutting a small flap, requiring only a single application of anaesthetic, and was completed very quickly thanks to the use of a Safe surgical guide (Materialise) and EchoPlan surgical kit (Sweden & Martina). A downsizing technique was used for the implant site, due to poor bone density (3/4 ratio). An assessment analysis between the virtual project and actual execution showed a substantial superimposition and level of precision of the guided implantology system used.