The Immediate Provisional Hybrid

[Anonymous]

A growing patient population is missing some or all of their teeth. In the past, the only treatment option for patients whose dental health had deteriorated to this extreme was a removable partial denture or a full denture.

Unfortunately, the replacement of natural teeth with dentures is commonly associated with some undesirable physical and emotional changes. Patients who had all of their teeth removed and replaced with an immediate denture frequently found the abrupt transition very difficult. As soon as the teeth are removed, the constant stimulation to the bone once provided by chewing no longer occurs, and the bone that once supported the teeth and soft tissues begins to resorb (Figure 1).
Over time, changes in the mouth can cause dentures to fit poorly, creating uncomfortable pressure on gum tissues. Many denture wearers experience difficulty with maintaining a proper diet because eating is associated with denture pain or discomfort. Dentures can also interfere with speech and cause social embarrassment when they slip unexpectedly. Overall, in the long-term, most patients have found dentures to be a less than satisfactory solution.

EARLY IMPLANT METHODS
Dental implant technology has undergone significant evolution. In the early days, the dentist refracted the gum tissue to visualize the bony anatomy. This visual assessment and strategic implant placement was critical in order to avoid damaging nerves and to ensure the proper position and function of the final replacement teeth. (Visual assessment yields less predictable results when there is extensive bone loss, or when multiple implants are planned.)

The implants were then left undisturbed for 6 to 9 months to allow the titanium implant posts to form a secure bond with the jawbone. During the 6 months (or so) while the titanium bonded to the bone, the patient either went without teeth or continued to wear the old dentures. In a second procedure, the implants were uncovered and the posts were attached. The teeth were then affixed to those posts.

With the development of dental implants, dentists are able to offer a superior alternative to the conventional partial or full denture. Additionally, new improved implant procedures have been developed and refined in response to the demand for greater accuracy and shortened treatment time. These new procedures enable the restoring dentist to place dental implants and attach replacement teeth in the same visit.

        

[Anonymous]

image

        

[Anonymous]

CASE REPORT
Immediate Provisional Hybrid Technique:
For our patient, the treatment process began by making a denture: the same type that is typically created when teeth are extracted or existing dentures are replaced. This is to be converted into a temporary hybrid denture at the time of implant surgery. The surgeon then placed dental implants, installed temporary abutments (Figure 2), and the extraction sites were sutured to close the tissues.

Next, the restoring dentist modified the new denture to fit over the temporary abutments (Figure 3a). Although there is a short learning curve associated with this step, it becomes very easy after completing a few cases. This step can be completed ahead of time if the implants are placed with an implant placement system such as NobelGuide (Nobel Biocare). A presurgical working model was made using a surgical template, and the holes were predrilled prior to the day of surgery (Figures 3b and 3c).

After the denture was properly fitted over the temporary abutments (Figure 4), the denture was processed in the mouth to the abutments. First, the access holes were plugged with plastic Q-tip rods to prevent acrylic from closing off the opening to the abutment screw. Then, the denture was processed to the abutments using fast-set denture repair acrylic. This was done by placing the uncured acrylic in a plastic syringe and expressing it into the opening in the denture next to the abutments (Figure 5). The denture was held firmly in place until the acrylic cured completely. After it was cured, the Q-tip plugs were removed and the denture was converted into an implant-supported hybrid denture. All excess acrylic, and most of the denture flange, was removed to make a high-water-type appliance. After adjusting the appliance, the underside was polished and glazed for a smooth finish that would facilitate proper hygiene (Figure 6).

The hybrid was then attached back to the implants. The screws were torqued to 35 Ncm, then the access holes were filled with cotton and Cavit (3M ESPE).

The patient left the day of surgery with a fixed-hybrid denture (Figure 7) that served him for 3 to 4 months while the implants completely integrated.

During this time, we addressed any issues of occlusion and function. The patient was restricted to only fork-mashed food for the first 3 months, after which he was able to resume eating normal food.

The final restorations were delivered at 4 months post surgery, and the patient was extremely pleased with the final outcome (Figure 8).

        

[Anonymous]

figures for reference..

        

[drmithila]

A growing population of patients are missing some or all of their teeth. In the past, the only treatment option for patients whose dental health had deteriorated to this extreme was a partial or full denture.

Unfortunately, the replacement of natural teeth with dentures is commonly associated with some undesirable physical and emotional changes. Patients who had all of their teeth removed and and replaced with an immediate denture frequently found the abrupt transition very difficult. As soon as the teeth are removed, the constant stimulation to the bone once provided by chewing no longer occurs, and the bone and tissue structures that once supported the teeth begin to resorb (figure 1).

Over time, changes in the mouth can cause dentures to fit poorly, creating uncomfortable pressure on gum tissues. Many denture wearers experience difficulty with maintaining a proper diet because eating is associated with denture pain or discomfort. Dentures can also interfere with speech and cause social embarrassment when they slip unexpectedly. In the long-term, most patients have found dentures to be a less than satisfactory solution.

EARLY IMPLANT METHODS

Dental implant technology has undergone significant evolution. In the early days, the dentist refracted the gum tissue to visualize the bony anatomy. This visual assessment and strategic implant placement was critical in order to avoid nerves and ensure proper position and function of the final replacement teeth. (Visual assessment yields less predictable results when there is extensive bone loss or when multiple implants are planned.)

The implants were then left undisturbed for six to nine months to allow the titanium implant posts to form a secure bond with the jawbone. During the six months or so while the titanium bonded to the bone, the patient either went without teeth or continued to wear the old dentures. In a second procedure, the implants were uncovered and the posts were attached. The teeth were then affixed to those posts.

With the development of dental implants, dentists are able to offer a superior alternative to the conventional partial or full denture. Additionally, new improved implant procedures have been developed and refined in response to the demand for greater accuracy and shortened treatment time. These new procedures enable the restoring dentist to place dental implants and attach replacement teeth in the same visit.

        

[drmithila]

image

        

[drmithila]

IMMEDIATE PROVISIONAL HYBRID

The treatment process begins with making a denture, of the same type that is typically created when teeth are extracted or existing dentures are replaced. This is converted into a temporary hybrid denture at the time of implant surgery. The surgeon then places dental implants and installs temporary abutments (Figure 2). The extraction site is sutured to close the gum tissue.

At this time, the restoring dentist modifies the new denture to fit over the temporary abutments (Figure 3a). Although there is a short learning curve associated with this step, it becomes very easy after completing a few cases.

This step can be completed ahead of time if the implants are placed with the NobelGuide procedure by Nobel Biocare. A presurgical working model is made using a surgical template and the holes are predrilled prior to the day of surgery (figure 3b, 3c).

After the denture is properly fitted over the temporary abutments (Figure 4) the denture can be processed in the mouth to the abutments.

The access holes are plugged with plastic Q-Tip rods to prevent acrylic from closing off the opening to the abutment screw.

The denture is now processed to the abutments using fast-set denture repair acrylic. This is achieved by placing the uncured acrylic in a plastic syringe and expressing it into the opening in the denture next to the abutments (Figure 5).

The denture is held firm until the acrylic cures completely. At this time, the Q-Tip plugs are removed and the denture in converted into an implant-supported hybrid denture. All excess acrylic and most of the denture flange is removed to make a high water type appliance.

After the appliance is adjusted, the underside is polished and glazed for a smooth finish that facilitates proper hygiene (Figure 6).

The hybrid is then attached back to the implants. The screws are torqued to 35 Newtons and the access holes covered with cotton and cavit.

The patient left the day of surgery with a fixed hybrid denture (Figure 7) that served him for three to four months while the implants completely integrated.

During this time, we addressed any issues of occlusion and function. The patient was restricted to only fork-mashed food for the first three months, after which he was able to resume eating normal food.

The final restorations were delivered in four months. The patient is extremely pleased with the final outcome (Figure 8).

        

[drmithila]

figures..

        

[drmithila]

Jeff T. Blank, DMD

INTRODUCTION

There is possibly nothing more frustrating in the practice of dentistry than struggling with retaining single unit provisional restorations. It is both embarrassing for the dentist and a huge inconvenience for the patient to return to the office to recement a temporary. Most dentists will agree that aside from dental pain, many if not most of after-hours calls are related to dislodged temporary restorations.

CLINICAL TIPS

This short article will present a few clinical tips for ensuring that single unit provisional restorations not only stay put for the interim period prior to final crown delivery, but assist in reducing final restoration adjustments as well as ideal tissue health and patient comfort:

Clinical crown height and classic retention and resistance form are imperative for adequate provisional retention. Personally, I constantly feel the need for the double cord technique if for no other reason than to get as much apical migration of tissue to permit a decent prep height. This is particularly true with maxillary and mandibular second molars. Rarely is there enough clinical crown height above/below the retromolar pad and tuberosity area to get more than a few millimeters of prep height on the distal of these teeth. I certainly am cognizant of the fact that if you are using a bonded restoration, it is not always necessary to have much clinical prep height for the final ceramic restoration, but you are setting yourself up for problems when it comes to retaining the provisional restorations.

Retention and resistance form are both things we all know and appreciate, so I won’t expand on those concepts per se. However, I have found over my 21 years of practice that when I was not routinely replacing all previously existing amalgams/composites prior to or during the prep, pieces would fall out etc… during the prep and I would have the tendency to try to cut a box or basically “go with it” in terms of retention and resistance form. As I began using all ceramic crowns, especially those that must be bonded in rather than cemented, it became essential of course to remove all amalgam. When an adequate new core is placed, ideal prep form is easily achievable and along with packing cord or using a diode laser to increase prep height, these key issues were routinely addressed.

Lastly and probably most importantly, developing functional occlusion with no working or non-working interferences is a key factor in contributing to temporaries falling off. Most, if not all, of us delegate provisional fabrication to our assistants. I think it is essential that we really sit down and educate our assistants in not only how to make a good provisional index (several great methods exist), we must assist them in developing a working knowledge of dental morphology and occlusion. Several great books exist (the best are lab technician books) that do more than show basic primary posterior anatomy and illustrate the importance of developing proper cuspal inclines and the role these play in occlusion. Simply taking a preoperative dual-arch tray impression of the damaged tooth to be crowned is rarely sufficient in rendering a provisional that meets the demands of morphology and occlusion. More adept assistants are more than eager to learn techniques to correct the occlusion and morphology of the tooth prior to impressing for the index and this can be easily taught to them using a little bit of self-etching bonding resin and composite. Even if the assistant is sub par, we can certainly do it for them in minutes while the patient is getting numb. The key is for the whole clinical team to recognize those teeth that are occlusally unsound (working/non working interferences, lack of sufficient cusp contact etc…) by simply using articulating paper prior to impressing for the index. Once this becomes routine, then you will also see that in those cases where there is sound occlusion, you will want to replicate those contacts in the provisional. Failing to maintain healthy occlusal contacts lead to just as many problems as not recognizing occlusal interferences. How often have we had patients complain that the adjacent nonrepaired teeth were sore because we left our temps out of or light in occlusion, not to mention the potential of supereruption and the woes of excessive occlusal adjustment of the final crown as the result? I would go as far as to say that not checking working and nonworking interferences are probably the largest single contributor to temps coming off…so it is imperative that we teach this or check every temp ourselves.

        

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