Introduction to Prosthodontics PDF

# CHAPTER I Introduction ## INTRODUCTION TO PROSTHODONTICS ### Terminology - **Prosthetics**: The art and science of supplying, fitting, and servicing artificial replacement for missing parts of the human body. - **Prosthesis**: The replacement of a missing part of the human body by an artificial...

# CHAPTER I Introduction ## INTRODUCTION TO PROSTHODONTICS ### Terminology - **Prosthetics**: The art and science of supplying, fitting, and servicing artificial replacement for missing parts of the human body. - **Prosthesis**: The replacement of a missing part of the human body by an artificial part (e.g. eye, leg or arm prosthesis). - **Prosthodontics or Prosthetic dentistry**: The branch of dental art and science that is concerned with restoration and maintenance of oral function by replacement of missing teeth and surrounding structures by artificial devices. - **Dentulous**: A condition in which all natural teeth are present in the oral cavity. - **Edentulous**: A condition in which natural teeth are absent in the oral cavity. - **Partially edentulous**: A condition in which some of the natural teeth are absent in the oral cavity. - **Completely edentulous**: A condition in which all of the natural teeth are absent in the oral cavity. - **Complete Denture**: A dental prosthesis that replaces the entire natural dentition and its associated structures of the mandible and/or maxilla. - **Partial Denture**: A dental prosthesis that replaces one or more, but not all, of the natural teeth and its supporting structures and is supported by teeth and/or mucosa. It may be fixed or removable. - **Immediate denture**: A dental prosthesis that is constructed before extraction of teeth and is inserted at the time of teeth removal. ## Introduction to Complete Denture Prosthodontics ### Components (Parts) of a Complete Denture - **Denture base**: The part of the denture that rests on the tissue foundation and carries the artificial teeth. - **Denture border**: The margin of the denture base at the junction between the polished and the impression surface. - **Denture Flanges**: The vertical parts of the denture base that extend from the cervical margin of the teeth to the borders of the denture are called denture flanges. They are named according to their location: - **Buccal flange**: The portion of the denture that is related to the cheek and occupies the buccal vestibule. - **Labial flange**: The portion of the denture that is related to the lip and occupies the labial vestibule. - **Lingual flange**: The portion of the mandibular denture that is related to the tongue and occupies the lingual sulcus. - **Palatal portion**: The portion of the maxillary denture that is related to the palate. ### Surfaces of a Complete Denture - **Polished Surface**: The outer (external) surface of the denture that carries the artificial teeth. It includes the facial surface which faces the lips, the buccal surfaces which face the cheeks and the lingual and palatal surfaces which face the tongue and the palate. - The labial, buccal and lingual surfaces of the teeth are part of the polished surface. - **Occlusal Surface**: The surface that the teeth that makes contact with its antagonists (opposing dentition). - **Fitting Surface (Basal Surface)** : The surface that fits on the tissues. It is also called "Basal surface,” “Tissue surface,” and “Impression surface”. ## Objectives of Complete Denture Construction - **Restoration of masticatory efficiency**: Mastication is an important function of the teeth. Hence when they are lost, masticatory efficiency is significantly affected. Chewing of food and mixing it with saliva is the first step in digestion. Therefore teeth are necessary for optimal health, since their loss may lead to improper food digestion which may eventually lead to digestive disorders. Moreover, chewing makes eating more enjoyable. - **Restoration of facial appearance**: Teeth and their supporting bone play a great role in maintaining normal facial dimensions and contours, as they provide support for the lips and cheeks. Loss of teeth results in a prematurely aged (senile) appearance due to loss of support, and consequent falling in of the lips and cheeks. A properly constructed denture will restore the patient's normal appearance. In addition to soft tissue changes, loss of natural teeth leads to resorption of the alveolar bone; the improper placement of artificial teeth without consideration of the bony changes will result in improper support of the lips and an unpleasant appearance. - **Correction of speech defects**: Teeth are essential for effective speech as they play a role in the production of certain sounds. Proper placement of artificial teeth is hence necessary to correct the speech defects that result from loss of natural teeth. - **Preservation of the remaining natural tissues**: The alveolar processes that developed with the teeth for the purpose of supporting them resorb to a varying extent after teeth loss. Restoration of the chewing function through dentures minimizes the rate of alveolar atrophy. Moreover, with the loss of teeth, the temporomandibular joints are subjected to continuous strains because the mandible closes in abnormal positions. Restoration of normal degree of jaw separation helps to preserve the joints and stop the development of abnormal chewing habits. - **Patient satisfaction and comfort**: By achieving the previously mentioned objectives, the patient can psychologically accept his complete denture and his satisfaction and comfort can be attained. ## Steps of Complete Denture Construction Complete denture is the outcome of several steps. Some of these steps are clinical (i.e done in the clinic in the presence of the patient) and others are laboratory (i.e. done in the laboratory in the absence of the patient).(The success of complete denture depends on the skill with which both clinical and laboratory steps are carried out.) The outline of these steps is presented in the following table. | Clinical Steps | Laboratory steps | |:--:|:--:| | 1-Examination and Diagnosis | 3-a- Pouring study casts | | 2- Preliminary impressions. | b- Construction of special trays. | | 4- Final Impression | 5-a- Pouring of master casts. | | | b- Construction of occlusion blocks | | 6- a- Jaw relation registration | 7- a- Mounting of the casts on an articulator | | b- Selection of artificial teeth | b- Setting up of artificial teeth | | | c- Waxing-up | | 8- Try-in stage | 9-a- Facebow index for clinical remounting | | | b- Flasking | | | c- Wax elimination | | | d- Packing of acrylic resin | | | e- Curing | | | f- Deflasking | | | g- Laboratory remounting | | | h- Finishing and polishing | | 10- New interocclusal records for clinical remounting and occlusal adjustments | | | 11- Denture delivery and patient Instructions | | | 12- Inspection and after care. | |