A NEW APPROACH FOR MAKING A HOLLOW DENTURE USING CARAMELIZED SUGAR AND PUMICE

1. Professor and Head, Department of Prosthodontics and crown & bridge, JSS dental college and hospital, A Constituent college of Jagadguru Sri Shivarathreeswara University, SS Nagara, Mysuru, 570015, Karnataka, India. 2. PG Student, Department of Prosthodontics and crown & bridge, JSS dental college and hospital, A Constituent college of Jagadguru Sri Shivarathreeswara University, SS Nagara, Mysuru, 570015, Karnataka, India. 3. Professor, Department of Prosthodontics and crown & bridge, JSS dental college and hospital, A Constituent college of Jagadguru Sri Shivarathreeswara University, SS Nagara, Mysuru, 570015, Karnataka, India. 4. Principal and Professor, Department of Prosthodontics and crown & bridge, JSS dental college and hospital, A Constituent college of Jagadguru Sri Shivarathreeswara University, SS Nagara, Mysuru, 570015, Karnataka, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History

Fabricating a denture with perfect retention, stability and support is a challenging task for a prosthodontist. In the patients with long lips or highly resorbed ridges the denture height has to be increased which might compromise on these principles. With the increase in height subsequent increase in weight also occurs. For achieving a satisfactory esthetics, retention, stability and support, it becomes mandatory to make the denture light. This paper describes a simplified approach for making a hollow denture using sugar caramel and pumice mixture. This technique allows the caramelized sugar pumice to be bounded and stiff to sustain the packing pressure. At the same time it also dissolves easily when it comes in contact with water. The area required to be hollow is entirely under the control of the dentist with this cost effective and simple technique.

Introduction:-
Severely atrophied maxilla and long lips possess a clinical challenge for fabricating a successful denture. In order to attain an acceptable occlusal plane, the final result is a long and heavy denture. The denture thus formed has compromised retention and stability owing to the gravitational pull and unusual leverage. [El Mahdy 1969] Reducing the weight of the obturators have been successfully tried. Various methods have been tested in the past to reduce the weight of the dentures. Materials used to make the cavity in the planned space in dentures were dental stone [Challian 1972], silicone putty [Holt 1981, O'Sulivan 2004, modeling clay [Eliott 1983], thermocol, salt etc. primary problem with salt was that it was not easy to control the spread while packing. Salts could not be confined in the planned hollow space, which could result in exposure in the unwanted denture surface. Thermocol dissolves readily on contacting with the monomer. Other procedures were difficult to retrieve or costly. This led to the necessity of a material which was easy to contain and easy to retrieve. This paper describes an innovative method of using the sugar and pumice mix to create a hollow denture. Hospital, a constituent college of Jagadguru Sri Shivarathreeeshwara University, Mysuru, Karnataka with looseness of the previous dentures and desired the replacement of the same. He had been edentulous since 13 years and a denture wearer since 12 years. Intraoral examination revealed that he had a more than normal interarch distance. Extraoral examination revealed a long unsupported lip. Considering his requirements a treatment plan was made. It was decided to provide him with a hollow denture.
Preliminary and final impressions were made in the conventional way. Jaw relation was carefully recorded because of the long lip length and an increased interarch distance. After teeth selection and teeth arrangement, try in was done. All the methods were conventionally followed till dewaxing (Figure 1).  After dewaxing a layer of aluminum foil was adapted to the cast in the dewaxed mould ( Figure 2).  Sugar and pumice was mixed and placed on a spatula. Spatula containing the mix was heated over the flame till the sugar caramelized; this can be assured by the change in the color of the mixture to brown. The hot melted sugar and pumice mix was in a flowable consistency, and hence poured carefully from one end over the aluminum foil to the other ( Figure 3).  This mixture was allowed to set till it became hard.  A layer of wax was placed over the teeth in the counter flask and inverted over the caramelized sugar mix to check the overextensions if any. Any overextension of the sugar mix will be seen as an indentation on the wax. The overextended area of the caramelized sugar mix can be carefully trimmed with a sharp knife. This stage helps to inspect and plan the exact hollow area required. This also allows making sure if there is sufficient space for a uniform layer of acrylic resin on the buccal and palatal surface.  The hard set mixture is then peeled off easily from the aluminum foil (Figure 4,5).  Separating medium is applied to both the sides of the flask, like in a conventional packing.  A thin layer of heat cure poly methyl methacrylate (DPI, Mumbai) is placed in a dough stage on both the sides of the dewaxed moulds.  The set caramelized sugar pumice mix is then placed over the acrylic dough in one of the sides of the mould and packed ( Figure 6). This mixture doesn't shift during packing due the hard consistency of the caramelized sugar.  After processing, denture is deflasked, trimmed and polished.  A layer of brown caramelized sugar and pumice can be easily detected (Figure 7).  Holes are created on the flange area and the denture is immersed in water for 2 days. The sugar mix dissolves and the remnants, if any, are cleared by forceful injection of water into the holes.  The holes are then filled with autopolymerizing polymethylmethacrylate (DPI RR, Mumbai) in a doughy consistency (Figure 8). Hollow consistency was confirmed by placing the denture in water. The denture must float and no air bubbles must be evident.

Discussion:-
Geriatric patients have limited treatment modalities when it comes to rehabilitation of the missing teeth. Heavy dentures have the poor retentive ability and cause a lot of discomfort. Reducing the weight in such cases give a satisfactory result. Lost salt technique is the most widely used technique to make a denture hollow. But it is difficult to contain salt at a particular area. The present article describes the technique using caramelized sugar and pumice which becomes hard when set and doesn't change in shape during packing. Also the retrieval is not a difficult procedure.
Some authors suggest the use of putty for creating hollow space, but putty is a costly material and also retrieval of putty is a cumbersome task. Thermocol do not stay in one particular position. If stabilizing the thermocol is attempted by using cyanoacrylate, thermocol is seen to dissolve. Thermocol also dissolves by monomer during packing. This questions the credibility of the thermocol to be used as an effective material in hollow dentures.
The main advantage of caramelized sugar is the containability and easy retrievability. The sugar and pumice mixture when heated forms a viscous fluid and flows easily to the desired area (on the aluminum foil). After cooling this mixture becomes hard and sustain its shape without distorting. This hard set mix can be placed wherever possible, easily without sticking or breaking. When it comes in contact with water, it readily dissolves and creates a hollow cavity. Precaution to be taken in this present technique is the dimension of the sugar mix. The dimension should not be too big to take up the space for the acrylic resin around the sugar pumice mix. To check this, a sheet of wax is kept on the counter flask and trial closures are performed till uniform space for resin is established. The disadvantage of this procedure could be the time consuming nature and the handling of the sugar till a precise temperature requires skill of the clinician.