Patent Publication Number: US-2021186657-A1

Title: Dental dam and method of use

Description:
FIELD OF THE INVENTION 
     The invention relates to the field of dentistry. More particularly to an improved dental dam and clamp arrangement, wherein the clamp is engageable with a dental dam membrane and may form part of a dental dam kit. Additionally, the invention teaches a method of use of the new dental dam and clamp arrangement kit. 
     BACKGROUND OF THE INVENTION 
     Dental restoration procedures often require the oral structure of interest be isolated from moisture, such as saliva in the mouth and from other fluids such as anesthetising compounds. Additionally, a work area is created in the mouth during the restoration processes, which work area may create filing compounds or other incidental particulates. The dental dam seals off the patient&#39;s upper throat from the work area such that the filings or particulates cannot be swallowed or ingested. 
     To provide the dry, isolated, work area a dental dam is used. The dam includes a membrane which is placed over and around the oral structure of interest. The membrane is commonly formed of a rubber material, such as latex, and includes a plurality of punched holes, each of which closely match the structure. If the membrane does not include these perforations or pre-punched holes, a separate tool (punch) will have to be used to form the appropriate hole. The membrane, which commonly includes a frame to maintain the planer shape of the membrane, is mounted and the hole is pressed over the structure to isolate it. The elasticity of the material retracts the membrane around the structure, to form a snug fit over the structure to prevent the ingress of moisture. 
     Whilst work is continuing, the dam or membrane has the tendency to pull off from the structure. This possess a problem and various attempts have been made to develop a clamp, which can be secured to a structure and over the membrane, to keep the dam or r membrane in place. 
     Commonly these clamps are metallic and include two opposing surfaces which are kept in close abutment by a joining body. The clamps are usually biased toward one another to provide the clamping effect. A separate tool is needed to pull apart the two surfaces for placing and removing the clamp. The intense clamping force can cause pain to a patient. More so, clamps of different sizes exist which means that several clamps would have to be tried and fitted to a patient in a single sitting. This placing and removing of clamps, as well as the metallic nature thereof, contribute to the pain experienced by the patient. 
     In practice a dental dam and clamps becomes expensive. The cost arises not only from the dam and clamps, but also to the associated tools, such as the punch, forceps and the frame, used for mounting the dam correctly. 
     OBJECT OF THE INVENTION 
     It is an object of the current invention to address the above mentioned problems, at least to a degree, by providing an improved dental dam and clamp arrangement, in which the clamp is attachable with the dam and wherein the clamp and dam are formed from the same material. 
     SUMMARY OF THE INVENTION 
     In accordance with a first aspect of the invention there is provided a dental dam which includes a substantially planer membrane, having; at least one locating portion on the membrane; and a guide formation along a major surface of the membrane; and a clamp arrangement engageable with the guide formation; wherein the membrane and the clamp arrangement are formed of a shape memory polymer. 
     The invention provides further for the clamp arrangement to be formed of the shape memory polymer manipulated to create an oral structure engaging member; further the clamp may include an undercut section for engaging the clamp with the formation in a slidable manner; further still the clamp may include a handle, for positioning the clamp toward the oral structure; more further still for the clamp to include a pocket region, used for engaging the oral structure; more further still the pocket region may include at least two opposing surfaces, shaped to engage an oral structure; further where the two opposing surfaces may be biased toward each other. 
     The locating portion on the membrane may be one of the following; an aperture through the membrane or a perforated hole through the membrane or a marking on the membrane. 
     The invention provides that the formation may be a projection formed in the major surface of the membrane, further the formation may be a tendon which runs along the major surface of the membrane. 
     The dental dam may include a frame, toward the perimeter of the membrane, and the frame may retain, at best, the substantially planer shape of the membrane. 
     In accordance with a second aspect of the invention there is provided a dental dam clamp, for use in restorative dental procedures, formed of a shape memory polymer manipulated to create an oral structure engaging member. 
     The invention provides further that the member may include a handle and a pocket region; further the pocket region may include at least two opposing surfaces; still further the opposing surfaces may be shaped to engage an oral structure; further still the opposing surfaces may be biased toward each other. 
     In accordance with a third aspect of the invention there is provided a method for using the dental dam according to the invention, the method comprising the following steps; 
     placing a flexible membrane to a frame to create the dental dam, as described in the first aspect of the invention above; 
     positioning the dam over the mouth of a patient such that the guide formation along a major surface of the dam faces away from the patient; 
     further, positioning the dam to align the locating portion of the membrane over an oral structure; 
     using the arm of the frame to secure the dam in position; 
     depressing an area of the membrane around the locating portion about the structure until the structure projects through the portion; 
     allowing the area to retract about the base of the structure to isolate the structure; 
     locate the guide formation along the major surface of the membrane; 
     engaging to the formation, a clamp arrangement as described in the first or the second aspect of the invention above; 
     slidably moving the clamp arrangement along the formation to align the pocket region of the clamp over the structure; 
     pressing the clamp in a direction toward the structure; and 
     receiving the structure in the pocket region. 
     The invention provides further still for the shape memory polymer to retain a first shape when manipulated into said shape at a first temperature; further for the shape memory polymer to revert to a second shape at a second temperature; further where the first temperature and the second temperature may be different temperatures; further still where the first shape and the second shape are different shapes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of the invention will become more apparent by the following description of the embodiments, which are made by way of example, with reference to the accompanying drawings in which: 
         FIG. 1  shows a view, in perspective, of a dental dam in accordance with the invention; 
         FIG. 2  shows a view, in perspective, of the clamp arrangement in accordance with the invention; 
         FIG. 3  shows an additional view, in perspective, of the clamp arrangement of  FIG. 2 ; and 
         FIG. 4  shows the steps to be followed in the method of using the invention. 
     
    
    
     BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1  which shows a dental dam  10  in accordance with the invention. The dam includes a substantially planer membrane  12  having a plurality of locating portions, collectively numbered  14 , a guide formation  16  and a frame  18 . A clamp arrangement  20 , having a handle  22  and pocket region  24 , is shown engaged with the guide formation. 
     The membrane  12  and the clamp arrangement  20  are both formed of a shape memory polymer. The polymer, specifically a shape memory rubber, is a material which can be manipulated to a new shape, and retain that shape until heated. Once heated the polymer will revert to its initial shape. 
     The material stretches at a higher temperature, but at lower temperatures will stiffen and harden, thus retaining the new form. Once the new form is no longer necessary the material may be heated to the higher temperature with the result that the material will revert to its initial shape. 
     Forming the membrane  12  and the clamp  20  of the memory polymer provides advantages over what is the current practice in the art. The membrane may provide for better isolation of an oral structure, particularly in setting the membrane about the structure and for removing the membrane once it is no longer needed. Traditionally clamps used in support of dental dams are a metallic material. These clamps compress intensely on the oral structure. The compression caused by the clamp is painful and uncomfortable to a patient. The clamp  20 , formed of the polymer, provides a conservative approach to securing the membrane and oral structure, such that the gingival tissues may remain largely unaffected and the need for local anaesthesia is generally not required. 
     These and other advantages of the use of the shape memory polymer will be discussed and explained in the description that follows. 
     Turning back to  FIG. 1  where, membrane  12  includes a major surface  26 , delimited by edges  28 A,  28 B,  28 C and  28 D. Frame  18  encircles the membrane toward the respective edges. The frame is used to hold the membrane substantially flat and moderately taught. The effect is such that the membrane provides a protective cover over the mouth and throat of a patient during a dental or restorative process. The frame includes an arm  30  to help in mounting the frame and for general use. 
     Locating portions  14  are positioned along the surface  26 . Each portion may be in the form of a pre-punched hole through the membrane; alternatively, a perforated hole which may be pressed about an oral structure; alternatively, the portion may be a marking along the major surface of the membrane. The marking may be any visual indicator to set out the position of the portion, which would be visible to a user. 
     The portions  14  are set out along the surface  26  in an elliptical fashion. The portions are representative of the position of oral structures of a patient, where each portion matches, as closely as possible, the location of an oral structure. The portions will aid the user in correctly aligning the membrane over the mouth of a patient. 
     Additionally, the elliptical shape of the portions  14  is centrally located on the membrane  12 . A user will thus be assured that the membrane is positioned correctly over the patients mouth, to cover the entire mouth region when a portion  14  is over the respective oral structure it represents. 
     In use, the area of the membrane  12  around a particular portion  14  will be pressed downwardly over the structure to be worked on. The structure thus protrudes through the portion  14 . The area about the structure serves as the isolating layer between the oral structure. Saliva, and other unwanted fluids are kept away from the structure by the membrane. 
     The guide formation  16  is positioned along surface  26 . The formation may be in the form of a protrusion formed on the surface, as a projection of the material of the membrane  12 . Alternatively, the formation may be a tendon which is secured to the surface. The tendon would preferably be formed of a metallic wire or other similarly rigid material. 
     The formation  16  provides a track which runs along the surface  26 . The clamp arrangement  20  is designed such that it will slide along the formation. This is discussed in more detail below. 
     The elliptical shape of the portions  14  will be matched, to a degree, by the formation  16 .) The formation may run alongside the portions on either an inner or outer circumference of the portion&#39;s ellipses. In the current embodiment, there exist a pair of formations  16 , which flank the portions, so as to place the elliptic shape of the portions in a channel  32 . 
     Referring to  FIG. 2  and  FIG. 3 , which show clamp arrangement  20  in accordance with the invention. The clamp, as formed of the shape memory polymer, is created by manipulating a single piece of the polymer into an oral engaging structure. 
     The clamp  20  includes an undercut section  34 , used for slidably engaging the clamp with the formation  16 , and for the purpose of creating the oral engaging structure, includes a handle  22  and a pocket region  24 . 
     The handle  22  is shown in the drawings as a bow, but this is not deemed to be limiting. As an example, the purpose of the handle could be served by having a projecting member of polymer which extends away from the pocket region. Any design which allows for a gripping and manoeuvring the clamp would suffice. 
     The pocket region  24  includes at least a first pair of opposing surfaces  40 A and  40 B. The surfaces are biased toward each other. The surfaces result in a clamping force being exerted against a structure placed therebetween. The force is exerted on what would be the front and the back of an oral structure, more correctly, the force is exerted against the lingual surface and the buccal surface of an oral structure. 
     To round out the pocket region  24  there is at least a second pair of opposing surfaces  42 A and  42 B. 
     The pocket region  24  is designed such that a downward pressure applied to the handle  22 , once the pocket region has been aligned over the oral structure of interest, will deform to a degree so as to receive the oral structure within the region. As may be seen in the drawings the region is formed as an opening, surrounded by the opposing surfaces,  40 A and  40 B, as well as  42 A and  42 B. The oral structure will thus protrude through the opening in a manner that clear access is made to the structure for further working. 
     Opposing surfaces  40 A and  40 B, under the influence of their nature bias, will clamp to the oral structure on the lingual and buccal surfaces. Opposing surfaces  42 A and  42 B pass between adjacent structures and provide added support and rigidity to the clamp  18 . 
     The undercut section  34  is formed toward a lower end  44  of the clamp  20 . The section is engageable with the formation  16 . When there exist a pair of formations, as shown in  FIG. 1 , the clamp will include a pair of undercut sections  34 A and  34 B to engage with each formation. 
     The clamp  20  and the formation  16  are engageable in a sliding fashion through engagement of the formation with the undercut section  34 . The section allows for controlled sliding movement of the clamp relative to, and along, the surface  26  of the membrane  12 . This sliding action will aid the alignment of the clamp. 
     Turning to  FIG. 4 , which shows a method of use of the dental dam  10 , in accordance with the invention. 
     First the membrane  12  is placed to a frame  18 , in such fashion to create a substantially flat surface of the membrane, thus creating the dental dam  10 . Additionally, the surface is taught, such that any deformation along the surface  26  is resisted by the nature of the material and the tensile arrangement attempting to retain the flat shape. 
     Next, using the arm  30  of the frame  18  to manoeuvre the dam  10 , finding the guide formation  16  which runs along the major surface  26  of the membrane  12 . Once the formation is located placing the dam over the mouth of the patient such that the formation is facing away from the patient. 
     Then, positioning the dam  10  so as to align a respective locating portion  14  over an oral structure to be worked on. Once the alignment has taken place, fixing the dam  10  in place by mounting or securing the dam through the arm  30 . 
     Next, depressing the area of the membrane  12  around the respective locating portion  14  about the oral structure of interest. The depressing force being such that the membrane slides down around the oral structure until the structure, or a sufficient portion thereof, projects through the membrane and the portion. 
     Once this occurs allowing the area of the membrane around the portion to retract about the base of the structure, thus isolating the structure. 
     Then, finding the guide formation  16  along the surface  26 . 
     Next, engaging the clamp  20  with the guide formation  16 . The clamp is preferably engaged by mating the undercut section  34  with the formation. This engagement provides for slidable movement of the clamp along the formation and over the surface. 
     Then, slidably moving the clamp  20  along the formation  16  until the pocket region  24  is aligned over the oral structure of interest. 
     Next, applying a force to the handle  22  in the direction of the oral structure, so as to receive said structure within the pocket region  24 . The structure thus protruding through the opening created by the pocket region, to be accessible for further work. 
     Then, allowing opposing surfaces  40 A and  40 B to exert a compressive force to the lingual and buccal surfaces of the oral structure, while additionally, allowing the opposing surfaces  42 A and  42 B to pass between adjacent structures and provide added support and rigidity to the clamp  20 . 
     Once the work is complete, and the removal is required, the user may pull the clamp  20  off the oral structure and withdraw the dam  10  from the patients mouth. If removal of either the clamp of the membrane  12  becomes problematic, the user may gently warm each until the material becomes elastic. The dam and clamp will then deform and allow for less restrictive and less painful removal. 
     The embodiment above provides a scenario in which the locating portions  14  are either holes, or perforated holes. If however, the portions  14  are merely marking on the surface  26  which serve as visual indicators, the user may include a step which involves punching through the membrane  12  at the position, using means well known in the art. The method for use would then continue in the fashion discussed above. 
     The description above additionally provides for embodiments in which the membrane  12  is black in colour, as opposed to a common green colour which is currently being used in the art. 
     A person skilled in the art will appreciate that a number of variations may be made to the above described invention or features thereof, without departing from the scope of the present invention.