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Whether it is nobler (wiser) to take the time to do the job appropriately or cut corners only to find that one never has the time to do it correctly the first time, but always manages to find the time to re-do it over again.
There have been great advancements in our field of restorative dentistry both from clinical as well as technological aspects. The area of implants is forever growing in leaps and bounds with new companies popping up like daisies. From the proven older systems to the newer snap crackle and pop technologies, we are being inundated with products.
With implants especially, it is of unforgiving importance that we adhere to ridged guidelines when reconstructing a single or group of prosthesis. This is important for patient comfort and function as well as for aesthetics. There is no shortcut to success.
As an old friend PKT, once said (“perfection is no trivia-but trivia makes perfection”).
The one concept which seems to have alluded all the manufactures is the design of angulation corrective abutments. i.e. those little pieces designed to correct the misaligned implant due to what ever reason. Placement can not always be exact due to many considerations which include amount of bone and density. In truth there are too many variation possibilities for any feasible pre-designed solutions. They come in limited degrees of angle and rotational correction. The end result is at best a questionable compromise.
Without question, the preliminary evaluations, design and fabrication of stints and diagnostic guides will contribute greatly to the end results. Any attempt to proceed without these is like walking blind through an unknown obstacle course. Many of us have been there. Well I need say no more.
This fall, Nobel Biocare will launch NobelActive™ – a unique new implant with revolutionary features due to the advanced design of its implant body.
For the clinician, NobelActive™ is indicated for all positions, but is especially effective in regions of diminished bone quality or quantity, due to its bone-condensing capability, capacity for shorter drilling protocols, and ability to change direction on insertion.
On the patient side, NobelActive™ offers a solution for difficult treatment situations and provides for quicker treatments, shorter healing times, and less invasive procedures.
The inventors of this radical design are Prof. Nitzan Bichacho and Drs. Ophir Fromovich, Benny Karmon, and Yuval Jacoby. For first-hand insight, Prof. Bichacho shares his experiences in developing and using NobelActive™.
“Before being sold to Nobel Biocare, this implant design has undergone more than three years of study and has been placed thousands of times, with equal – more often – better results than traditional implants,” claims Prof. Nitzan Bichacho, “There is no doubt the system will benefit even further from the enhancements introduced by Nobel Biocare.”
Prof. Bichacho refers to the well-proven TiUnite® surface and grooves – Groovy 4 – on the implant threads. The TiUnite® surface has been documented to improve osseointegration, promote soft tissue seal around the implant, and increase the esthetic result of implant rehabilitations. The NobelActive™ implant has a variable thread profile that becomes wider vertically and shorter horizontally, from bottom to top; the core of the implant forms condensing lines, unlike the linear profile as is the case with contemporary tapered implants.
This article will illustrate a method used in immediate implant loading to convert a conventional denture to a provisional hybrid restoration.This technique provides the patient with a rigidly fixed interim restoration at the time of implant placement or delivery of the converted prosthesis within a 24 hour time period.
A patient with severe periodontal disease required treatment with immediate dentures to be followed with dental implants on the mandibular arch. Fig. 1
The teeth were extracted and conventional immediate dentures were delivered in the usual manner. Fig. 2
After an evaluation of the new tooth position and acceptance by the patient, a clear duplicate of the immediate mandibular denture was made and a surgical template fabricated. Metal sleeves were incorporated to guide the surgical pilot drill.
A section of rubber dam is cut-out to act as a barrier to the auto-cure resin. This will be used later in the conversion process. Fig. 3
The surgical template/duplicate denture was reduced anteriorly to facilitate the surgery. An occlusal index was made to verify the jaw relationship and to orient the template at the time of surgery. Fig. 4
Dental implant therapy is expanding in scope, yet the original therapy designated for edentulism remains a significant challenge. Often the attainment of osseointegration of implants is considered the primary or principle challenge for the clinician. mHowever, new implant surfaces, improved imaging mtechniques and guided surgical procedures enhance the clinical process of implant placement and may enhance the osseointegration outcome. Prosthetic outcomes and patient satisfaction with the prostheses are important additional measures of success(Feine).
Following osseointegration of the implants, the subsequent challenge is the production of a prosthesis that provides an opportunity to a) maintain peri-implant tissue health, b) restore function and c) enhance esthetics. A conventional method of treating edentulism using dental implants is the placement of sufficient endosseous implants to support a screw-retained prosthesis containing a metal framework veneered with processed acrylic resin and denture teeth. Introduced by Branemark and colleagues (Adell et al 1981) and further popularized by Zarb and Schmitt (1990), this approach to restoration has several advantages that include a) the ability to replace missing alveolar tissue with acrylic resin, b) the capacity to overcome compromised implant locations, c) the potential to be easily rejuvenated by replacement of the veneer should wear or aging dictate, and d) relative cost when compared to porcelain fused to metal restorations.
Success with these prostheses demands careful planning of implant placement in relationship to the location of prosthetic teeth. More specifically, common problems include bridge screw fracture and veneer failure (White and Lewis, 1992). Passivity of the framework fit to the abutments (or implant) is a key prosthesis feature that can reduce the incidence of bridge screw fracture. This fitting of large gold alloy castings is a significant challenge in for an implant supported fixed denture.
Beautiful teeth revealed by a glorious smile; such is the wish of many of our patients who choose an implant-bone restoration of lost teeth. Today implantology provides simple, fast and highly successful therapy concepts.
History of Patient
• 23 years old
• Very Healthy
• Asian Decent
• Lost two anterior teeth during a fight in a bar.
• Chipped both lateral and cusped
• Bone structure stayed in tact
Build up of Laterals and cuspid with Crystobal composite
Oral Surgeon: Dr. Dennis Smiler
• Extract root tips
• Placed two 4.5mm Friadent XIVE Implants on the side of the two centrals.
• Placement of two 4.5mm Friadent Gingiva Former abutments and an acrylic removable prosthesis was placed in the patient’s upper arch.
• Patient was told by Oral Surgeon to return to referring Dentist, to modify removable prosthesis and replace the two gingival formers with two pre-fabricated 4.5mm EsthetiCaps.
• The patient did not follow instruction and visited dentist eight weeks after, you can see the result of the damage from the removable Prosthesis.The Damage on the labial surface and the interproximal papillas. Dr. A. E. Kenney then became involved with the case eight weeks after the integration of the Implants. She removed the Gingiva formers and exchanged them with two pre-fabricated Friadent EsthetiCaps, cut of the chimney of the EsthetiCap and then modified the removable prosthesis.
The firing stability or the resistance to deformations of a dental alloy becomes a very important issue when implant supported and screw retained cast frameworks have to be created. This is due to the fact that implants with good bone incorporation do not have the mobility known with natural teeth and thus the accuracy of fit of a cast framework becomes mandatory for a successful restoration. Furthermore, the larger the extension of a bridgework cast in on e piece becomes, the greater the difficulty gets to maintain the accuracy of fit achieved after casting until the last firing cycle for the ceramic.
The preferred framework materials used for implant supported restorations such as ceramic-fused-to metal alloys or mono metals like titanium do contain certain amounts of processing errors or can only be used together with a profound know-how in processing procedures in this special field of restorative dentistry in order to get successful restorations.
This goes especially for high gold content alloys together with spans and sizes exceeding the normal dimensions. These large implant supported bridgeworks, cast in one piece are especially difficult to realize and the 100% “passive-fit” rarely occurs.
Ingenious systems like spark-erosion or copy-milling exist on the market and offer the correction of non fitting frameworks to the implants. Unfortunately, these systems are too expensive for a large majority of dental labs. The same counts for the CAD/CAM systems, which allow an almost cost-effective processing of “cheap” non-metallic materials or titanium.
This has been our background for the development of a high gold alloy especially recommendable for implant supported restorations under consideration of all relevant processing parameters in order to find the best possible variant under the tested alloys.
I previously wrote in Spectrum Dialogue about what happens when a patient neglects his oral hygiene (Implant and Reality, Spectrum Dialogue Vol.5 No.2) and the repercussions. I further illustrated what happens when specialist, restorative dentist, dental technician and patient are looking for perfection (Implant and Reality, “Into Perfection”, Spectrum Dialogue Vol.6 No.2). In this issue, you will discover what happens when there is no communication and no planning between the members of this team. I do not call it imperfection, I call it a disaster. Here are some examples.
In figure 1, you can clearly see how the implant is supra gingival and the level of the edge of the implant (where the tooth is supposed to start) is much lower than where the gingival of the lateral should be. In this case, nothing could be done other than hiding the implant body with the zirconium crown and praying that the gum will stay where it is now (figure 2). In a case with a single unit anterior, it is important to have a diagnostic wax-up done. This wax-up should be exactly similar to the final result in the mouth.
Before starting the surgery, the patient should be able to visualize the end result. The dentist specialist should be able to evaluate tissue level, final tooth size and implant diameter in case any modification has to be done before the implant surgery.
Figure 3 is an interesting case as two implants are placed with no space at all. All what could be done is a full gold bridge to prevent super-eruption.
Patients may present with worn or broken overdentures that were retained by “O” ring superstructures requiring fabrication of a new overdenture. This may present a challenge when the “O” ring heads are an integral part of the implant as is seen with subperiosteal implants or it is not practical to remove the supracrestal portion of the overdenture to construct the new denture.
This article will address a technique to allow capture of the “O” ring heads and provide a master cast for fabrication of a completed overdenture.
Typically, “O” rings and their corresponding heads are available in limited diameters. It is important to identify this diameter so that an accurate master cast can be fabricated that replicates the heads intraorally. A caliper may be used intraorally to measure the “O” ring head. It is important to measure the head at its widest diameter to get an accurate size.
If a intervening bar is present between the heads this is blocked out with wax or other material to prevent the impression material from flowing under the bar and locking the impression intraorally. It is recommended that a medium viscosity impression material be used to create a master cast. Impression material is injected around the heads intraorally then an impression tray filled with additional material is seated and allowed to set. Upon setting the impression is removed and plastic analogs corresponding to the size of the “O” rings heads are snapped into the impression and a master cast is poured. Wax is placed over the analog heads to create a spacer between the record base and the analogs. A record base can then be fabricated to overlay the analog heads and a wax rim is attached. The record base/wax rim is returned to the dentist for adjustment for proper vertical dimension of occlusion and interarch records are taken. The casts are mounted at the laboratory and teeth are set in wax to be returned for intraoral try in.
In the previous article, we saw how to solve technically esthetic problems with zirconia, problems due to patients neglecting their oral health. There is nothing better than when the patient, the dentist, the specialist and the lab are on the same wavelength. The following cases show how important time, planning and provisional restoration are to manage the soft tissue.
They all are very crucial to a restoration’s success.
“TISSUE IS THE ISSUE” — CASE N°1
This case is similar to the one in my previous article, except that time and provisional restoration were not an issue. Plus, there was no negligence on the patient’s side.
Zirconia abutment made with a Procera CAD/CAM system (NOBEL BIOCARE) Fig1 , and porcelain layered on it with E MAX ( Ivoclar Vivadent )Fig2,in Fig3,the tow veneers mad with Empress IPS Esthetic (ivoclar Vivadent) bonded on the zirconia abutment and natural tooth, three months after insertion.
The most important thing is to maintain the soft tissue and the papilla around the implant and the natural tooth; and in order to do that ,the flap in time of surgery And the provisional restoration before implant placement and after are essential.
Fixed bridges have long been the restoration of choice for implant reconstruction. This type of restoration however, can create hygiene problems when a bone and tissue defect is restored.
An alternative is to construct a restoration that is easily removable by the dentist for periodic hygiene maintenance. Another option is to construct a patient removable milled restoration that provides the esthetics, function and comfort of a fixed appliance.
The restoration featured in this article utilizes an Ipsoclip plunger attachment, which is convertible from dentist-removable (SE) to patient-removable (RE) or vice versa, as both versions use the same housing. The Ipsoclip may be used with a separate locking screwbolt for a dentist-removable application or with a plunger, spring and backplate for patient-removable. Fig. 1 To achieve these, a milled substructure is necessary. Secondary plunger attachments are added for mechanical retention.
In direct proportion to the increase in successful use of implants, the saving of healthy roots for use in retaining overdentures has decreased over the past decade. “With the explosion in use of implants we now see the need for techniques and materials specific to Implant Dentistry rather than an adaptation of existing tooth dentistry procedures to optimize results”.1 The very high rate of success for implants and their predictable results has changed the thought process of many clinicians when designing the support mechanism for retention of an overdenture. Currently the last few remaining teeth are more likely to be extracted and replaced with endosseous implants as the means of support for a removable prosthesis.
“The use of dental implants to improve RPD design, with no rigid connection between implants and teeth and as few as possible prosthetic element requirements is a viable solution for patients”.2 However true this statement taken from literature reference may be, the perception of added complexity due to an increase in divergent angles when using a combination of root and implant attachments to retain an overdenture has further led to a decrease in the saving of roots for this purpose. The advancement of attachment designs with the ability to accommodate greater angles of divergence, and the use of a simple Angle Measurement Guide (Zest Anchors, Inc.) Fig. 1, have now overcome the challenges of this type of combination case.
When planning a combination root and implant retained overdenture or partial denture case, the measured angle of divergence between the retained roots and implants placed dictates the choice of available dental attachments that can be used (Fig. 2). The following is a partial list of overdenture attachments that can be used based upon the degree of angle measured:
We placed a titanium abutment into the ultrasonic cleaner, but then forgot about it while it stayed in the container overnight. In the morning, we were stunned when we saw what had happened. The abutment turned gray and looked like it had worn down. The edges were rounded off. When we tried it on the analog we noticed that the fit was affected as well. It became very loose; therefore it could not be used. What could have caused this? — Anonymous