PROTECTIVE SHIELD FOR DENTAL IMPLANT

A protective shield and a method to protect the peri-implant tissue from excess cement in a cement-retained implant are disclosed. The protective shield comprises a lingual wing, a buccal wing and a funnel-shaped protrusion to be seated and extended circumferentially around the abutment or a fixture in tissue-level implants to seal between the abutment or the fixture in tissue-level implants and the shield. The protective shield has a shearing line with inverted ledges and V-shaped notches on the mesial and distal end that create a tearing line to tear and remove the protective shield and thereby the excess cement. The protective shield is designed and made of flexible material, in various sizes by 3D scanning and printing technology.

FIELD OF THE INVENTION

The present invention relates in general to the dentistry industry and in specific to a protective shield for preventing peri-implant diseases in implant patients.

BACKGROUND OF THE INVENTION

Cement-retained dental implant treatment has been successful and favourable over screw-retained treatment to restore lost teeth due to an associated number of advantages. These include easier control of occlusion, higher esthetic results, good passive fitness, fewer complex manufacturing procedures, lower costs, and similarity to conventional methods of restoration in natural teeth. Nonetheless, cement-retained implants carry a problem of leaving excess cement on the implant or in the surrounding soft tissues, which has been associated with pen-implant disease and consequent implant failures. “Peri-implant disease” is disease that affects the tissues associated with an oral implant and/or abutment. Bacteria grow in the soft tissue (mucositis) or progress to the supporting bone and induce its destruction (peri-implantitis).

This problem has caused clinicians to choose screw-retained restorations, despite their deficiencies, such as lower esthetic results and reduced effective occlusal surface. The problem has been proven in several studies. A study involved 20 females and 19 males, ranging in age from 41 to 78 years, who used 34 of 42 test implants (80.95%) and no control implants (0%). Of the 33 test implants available for evaluation at the 1-month interval, the clinical and endoscopic signs of peri-implant disease had resolved in 25 implants. The study concluded that excess dental cement was associated with signs of pen-implant disease in the majority (81%) of the cases. Clinical and endoscopic signs of pen-implant disease were absent in 74% of the test implants after the removal of excess cement. All types of excess cement observed were associated with peri-implant disease. The peri-implant disease was not cement-specific—all types of cement can cause the disease.

There are some unspecific methods trying to avoid excess cement during implant prosthesis cementation such as using a rubber dam or replica technique however these methods do not specifically address this problem and their efficacy is controversial.“Gcuff ” has been designed for multiple purposes such as impression making and temporary gingival shaping made from a rigid material and not 3d designed with cad cam devices which is specific for each implant prosthesis.

The present invention provides a novel method and system to overcome the commonly occurring problem encountered during the cementation of dental implant prosthesis, namely excess cement residue on the implant-mucosal surface.

SUMMARY OF THE INVENTION

The present invention is a device and method to protect the peri-implant tissue from excess cement in a cement-retained implant. The present invention is a 3d meticulously designed protective shield that prevents the penetration of excess cement to peri-implant soft tissues, and it can be used with every implant system based on their specific 3d geometry. In addition, it can be customized and can be used in mass production as an adjunctive part with different implant systems. The solution involves the use of 3D printing technology which simulates and fabricates models precisely using a wide variety of materials, ranging from low flexible to highly flexible materials.

The protective shield's solution creates a layer that prevents the penetration of excess cement to peri-implant soft tissues. The simple, affordable, and efficient technique will assist clinicians in combating the issue. The protective shield's application will involve manufacturing a custom flexible and thin protective shield, by a 3d printer, upon scanning the abutment and its surrounding tissues and can be made specifically for different implant systems with mass production with any flexible material with data gathered from 3d specific designs with technology to reduce the costs.

The protective shield has a lingual wing facing toward the tongue and a buccal wing both having a curvature slightly upward on the distal ends and inverted ledges on the proximal ends. The shield further has a funnel-shaped circular opening in the center that extends downwardly to receive the abutment and has inverted ledges around the funnel which extend circumferentially around the implant.

The lingual wing and the buccal wing create a shearing part in connection to each other so that the shearing part in the funnel and shearing parts on the wings create a tearing line to guarantee the tearing and removing the excess cement according to the aspects of the present invention. In addition, the shearing part on the wings has V-shaped notches to facilitate the removal of the shield by tearing that from those areas. In addition, projections are designed to guarantee the removal of any remained cement.

The protective shield is easily placed on the abutment from the apical side to fit this component intimately. The position of the shield is at least 0.5 mm above the switched platform and 0.5 mm below the margin of the abutment, by considering the oral-facial direction of the shield. Once all these are completed, the abutment will be placed into the patient's mouth and tightened on the corresponding implant. At this point, everything is ready for implementing the cementation procedure.

After the cementation procedure is completed, any excess cement is pushed out and any entrapment is prevented as a result of the seal between the abutment and the shield. When the cementation procedure is complete, the shield is pulled out from the oral and facial sides, using a hemostat pliers to be torn from the V-shaped notches. It is worth mentioning that the projections on the weak areas of the shield help in removing any remaining excess cement from the area.

The protective shield has applications for both bone-level implants and tissue-level implants. The main feature involves a funnel-shaped barrier that is connected to the flat part and made with resilient 3d printed materials to seal the area. however, the protective shield will significantly benefit bone-level implants, due to the subgingival nature of bone-level implants.

Therefore, it is an object of the present invention to provide a system and method to prevent dental implant failure due to residual excess cement and save money and time for dental implant companies, dentists and patients.

It is another object of the present invention to wave the need for cast and abutment itself, as all procedures can be performed on digital data and sent via email by a dentist or a dental technician.

It is another object of the present invention to provide the capability to mass-produce prefabricated protective shields for different available brands of implants.

It is another object of the present invention to provide dental professionals with an improved prognosis of their patients, for more profitable practices.

it is another object of the present invention that is based on 3d scans and has some special features, and it can be made with a resilient material, so the results are more accurate than other methods and techniques.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A protective shield to protect the peri-implant tissue from excess cement in cement-retained implants is disclosed. The protective shield has applications for both bone-level implants and tissue-level implants, however, it will significantly benefit bone-level implants, due to the subgingival nature of bone-level implants.

According toFIGS.1to7, a bone level protective shield10is illustrated according to the present invention. The protective shield10comprises a lingual wing11facing toward the tongue and a buccal wing12facing toward the cheek. The lingual wing11and the buccal wing12are placed on an abutment adjacent to each other building a wing shearing line16. The protective shield has an upper side10aand a lower side.10band the wings are curveted slightly upwards on their distal ends11aand12a.

The wings11and12have a funnel-shaped protrusion13on the central lower side10bso that when placed on the abutment20adjacent to each other create a funnel shape opening to be seated and extended circumferentially around the abutment20. The funnel shaped protrusion13further has a funnel shearing line17so that the wing shearing line16and funnel shearing line17are placed adjacent and build a tearing line.

The wing shearing line16has inverted ledges14a,14baround the wing and V-shaped notches on the mesial and distal ends18a,18b. The inverted ledges of the wing shearing line and the funnel shearing line and the V-shaped notches on the mesial and distal end and the funnel shape protrusion create a tearing line to tear and remove the excess cement according to the present invention. The shield is designed so that the areas ended with V-shaped notches are reduced in thickness (weak areas) to facilitate the removal of the shield by tearing that from those areas. In addition to that, projections are designed above the weak areas to guarantee the removal of any remained cement.

According toFIG.1again the funnel-shaped part13has an inverted ledge15around the funnel that extends circumferentially around the implant to remove excess cement and make it safe to remove without any residue after dental implant prosthesis cementation procedure.

FIGS.3to7show the clinical step which involves placement of the protective shield10. The shield10is easily placed on abutment20from the apical side. The placement of the shield10is easy and fast due to the funnel shape of the bone-level abutments. The bone-level abutments have a crown margin22with an inverted ledge around the abutment margin23. The position of the shield10must be at least 0.5 mm below the abutment crown margin22so that the funnel part13of the protective shield encompasses the abutment cuff23, and 0.5 mm above the switched platform31of the abutment, and by considering the oral-facial direction of the shield. Once shield10is placed on the abutment20, the abutment will be placed into the patient's mouth and tightened on the corresponding implant30. At this point, everything is ready for implementing the cementation procedure.FIG.3shows the cement-retained crown19.

An amount of cement is provided to fix the restoration to an implant abutment. Usually, in the cementation procedure, the clinicians place in excess of20times more cement into the crown than is required. This overload of cement means that 95% is extruded out at the restorative margin, which is frequently found below the gum, making cement removal virtually impossible and causing diseases. The present invention helps the clinician to remove the excess cement and guarantees the removal of any remained cement.

Implants have a coronal or gingival end with a threaded bore extending upwardly. The coronal end extends downwardly along a cylindrical body to a distal end and connects to the abutment. The upper part of abutment21has a cylindrical configuration and extends to a bottom part that abuts against the coronal end of implant30. Abutments20may be provided with an engaging feature that engages with the implant30. The abutment has a crown margin22that includes a shoulder at the top portion. A corresponding ledge is formed along the exterior surface adjacent shoulder. The cuff23tapers outwardly and upwardly away from the coronal end of the implant and forms a frusto-conical shape. This tapering continues to a ledge and then transitions to taper inwardly at the upper portion of the cuff. A shoulder is located along the inner surface. This shoulder fits with the mating ledge on the exterior of the core. The protective shield is designed to fit tight around the abutment crown margin22and seal between abutment20and shield10.

When the cementation procedure is complete, the shield10is pulled out from the oral and facial sides, using a hemostat pliers to be torn from the V-shaped notches18a,18b. It is worth mentioning that the projections on the weak areas of the shield-wing shearing parts16and funnel shearing parts17help in removing any remaining excess cement from the area. The protective shield10is made of flexible material and in various sizes that help the easy removal of the shield.

Tissue-level implants require the margin of the restoration to be placed on the margin of the implant, which is often at the level of the soft tissue. As a result, it is less likely for tissue-level implants to have problems with excess cement. However, if required, the specification of the implant can be used to design the apical portion of the protective shield, since the location of the margin is not altered. For it to be easily placed, the shield should be manufactured from more resilient material to allow for insertion from the top of the implant fixture. The height of the apical part should not exceed 1 mm. It is apparent that producing prefabricated shields for tissue-level implants is easier than the bone-level types.

According toFIG.8the following steps will be undertaken for bone level implants800. In step801a scan of the definitive abutment is created. This scan is performed on the definitive cast while the gingival mask is removed. In step802another scan of the definitive abutment is created while the gingival mask is in place on the definitive cast. In step803the two created scans are superimposed on each other. In step804the lingual and buccal wings of the protective shield are designed from the resulting 3D scans. Then, the other part of the shield which is covering the supragingival part of the peripheral soft tissue should now be designed to create the funnel-shaped part of the protective shield. The amount of coverage in the facial and oral sides of the implant should be designed to surpass the outline of the crown by 3 millimetres. Additionally, the shield should be designed not to interfere with the seating of the restoration. Thus, a thickness of 0.5 mm is advised for this purpose.

In step805the designed protective shield is fabricated from a flexible material using a 3D printer. The weak areas (reduced thickness) ended to V-shaped notches are designed on the mesial and distal parts of the shield to facilitate removal of the shield by tearing that from those areas. In addition to that, projections are designed above the weak areas to guarantee the removal of any remained cement. When the digital workflow is adopted, the above-mentioned scanning procedures have often been performed previously, so that the net invested time for creating the shield would be minimal. Having all the data from previously performed scans, the remaining procedures to design the shield would be limited to merely determining the periphery of the shield and the place of the weak area and related notches.

In step806which is the clinical step involves placement of the protective shield. It is easily placed on the abutment from the apical side to fit the shield intimately. The placement of the shield is easy and fast due to the funnel shape of the bone-level abutments. The position of the shield must be in accordance with the above specifications—being at least 0.5 mm above the switched platform and 0.5 mm below the margin of the abutment, and by considering the oral-facial direction of the shield. Once all these are completed, the abutment will be placed into the patient's mouth and tightened on the corresponding implant.

At this point, in step807, everything is ready for implementing the cementation procedure. Any excess cement is pushed out and any entrapment is prevented as a result of the seal between the abutment and the shield. When the cementation procedure is complete, in final step808, the shield is pulled out from the oral and facial sides, using hemostat pliers to be torn from the V-shaped notches. It is worth mentioning that the projections on the weak areas of the shield help in removing any remaining excess cement from the area.

FIG.9shows the same procedure for tissue-level Implants. Tissue-level implants require the margin of the restoration to be placed on the margin of the implant, which is often at the level of the soft tissue. As a result, it is less likely for tissue-level implants to have problems with excess cement. However, if required, the specification of the implant can be used to design the apical portion of the protective shield, since the location of the margin is not altered. For it to be easily placed, the shield should be manufactured from more resilient material to allow for insertion from the top of the fixture. The height of the apical part should not exceed 1 mm. It is apparent that producing prefabricated shields for tissue-level implants is easier than the bone-level types.

The following steps will be undertaken for tissue-level implants900. In step901a scan of the definitive abutment must be taken. This scan must be performed on the definitive cast while the gingival mask is removed. In step902another scan of the definitive abutment must be created while the gingival mask is in place on the definitive cast.

In step903the two created scans must be superimposed on each other. The protective shield is designed from the resulting 3d scans. This shield should be designed to cover 1 millimetre below the fixture margin since it should be placed from above so it should be flexible enough to allow a complete seat from above. This modelling can be quickly rendered, having the characteristics of each commercially available fixture. This guides the excess cement out of the critical transgingival portion of the implant.

In step904the other part of the shield which is covering the supragingival part of the peripheral soft tissue should now be designed to create a funnel-shaped protective shield, extended circumferentially around the implant. The amount of coverage in the facial and oral sides of the implant should be designed to surpass the outline of the crown by 7 millimetres. Additionally, the shield should be designed not to interfere with the seating of the restoration. Thus, a thickness of 0.5 to 1 mm is advised for this purpose.

Shearing areas (reduced thickness) ended with V-shaped shearing notches designed on the mesial and distal parts of the shield to facilitate removal of the shield by tearing that from those areas. In addition to that, inverted ledges are designed above the shearing areas to guarantee the removal of any remained cement.

In step905the designed protective shield is fabricated from a flexible material using a 3d printer. When the digital workflow is adopted, the above-mentioned scanning procedures have often been performed previously, so that the net invested time for creating the shield would be minimal. Having all the data from previously performed scans, the remaining procedures to design the shield would be limited to merely determining the periphery of the shield and the place of the weak area and related notch.

This clinical step906involves the placement of a protective shield. It is easily placed on the abutment from the coronal (top) side to fit this component intimately and it should snap on the fixture collar to place just 0.5 mm below the margin. The placement of the shield is easy and fast due to the flexibility of the protective shield.

At this point, in step907everything is ready for the cementation procedure. Any excess cement is pushed out and any entrapment is prevented because of the seal between the fixture and the shield. When the cementation procedure is complete, in step908the shield is pulled out from the oral and facial sides, using hemostat pliers while the patient firmly bites on the cotton roll to be torn from the V-shaped notches. It is worth mentioning that the inverted ledges on the shield's weak areas help remove any remaining excess cement from the area.

For mass production, 3d data gathered can be used from previous scans for each specific implant system and can be used to make multiple instances of protective shields in different sizes. The shields can be customized for each abutment as a kit.

With respect to the above description, it is to be realized that the optimum relationships for the parts of the invention regarding size, shape, form, materials, function and manner of operation, assembly and use are deemed readily apparent and obvious to those skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.