A BULLETIN DEALING WITH ISSUES FOR DENTAL HEALTH PROFESSIONALS
Inside This Issue
1. Cosmetic Results with Attachments
2. Implant Over Dentures with SG Attachment
3. Complete Dentures Using the 10 / 20 Rule
4. Tooth Arrangement for Complete Dentures
6. Trade News
Cosmetic procedures are still at the top of the list for dentists. So the results of the 6th annual Dental Industry of Canada Survey (www.diac.ca) indicates. Dental lab products on the increase are All-Ceramic Crowns and Ceramic Veneers. The next group with the exception of mouth guards is implant supported crowns, bridges, partials and full dentures. Cosmetics is also vital with these types of restorations. Metal clasps, over sized attachments and loose fitting dentures will not meet the demands of the increasingly sophisticated patient. Dental professionals have the opportunity to provide a broad range of reliable cosmetic services that include the Bredent attachments. Versatility and broad compatibility reassures, that they can be used in cases supported by natural teeth, remaining roots and implants. Anchorage abutments fit the most common implant platforms. Prefabricated components simplify the working procedures and the retention sleeves can be changed chair side. The attachments provide space for flexibility of design and protection of the abutments. Implementation by the Techno-clinical team provides the ultimate benefit to the patient. For complimentary information on the attachments, call Dent-line of Canada at 1-800-859-7589
Palatal view of the VKS-SG Attachments on the Implant Bar In order to accomplish acceptable results, a close collaborative approach between the restorative team is important. The team can use two common approaches, a direct implant support or a bar supported over denture. During fabrication, clinical and technical complications should be reviewed. Fixed removable restorations for implants require proper aesthetics, phonetics, comfort, hygiene and favorable biomechanical stress distribution to the implants. This also improves the rehabilitation of resorbed ridges, since further tissue damage is neutralized by implant support. In this case the treatment plan had these objectives, restore and facilitate the incomplete over bite between the anterior area of the metal super structure. Then complete the restoration with a maxillary implant supported milled over denture, that would oppose a mandibular implant retained over denture secured by a ball attachment. Due to lack of manual dexterity, the Bredent VKS-SG attachment was selected for the maxilla, because it facilitated easy manipulation. Base plates and bite rims were fabricated and the vertical dimension of occlusion was determined. The upper and lower master models were mounted and it was evident that the teeth would have to be set up to correct a class III relationship. A maxillary chrome cobalt frame work would be required. An initial set up of the teeth were completed and tried in to evaluate centric relations, vertical dimension of occlusion, aesthetics and phonetics. Since the patient has a class III relationship, the lingual angulations of the lower implants helped in fabricating a class I horizontal relationship. The facial view of the upper model and palatal index showed a limited amount of available space in the anterior region. Buccal indexes also evaluate the space available for the infrastructure and in the definitive set up of the teeth. The occulsal view indicates that cross-arching with an anterior bar over the ridge is not possible due to the lack of space indicated by the palatal index. Aesthetics and phonetics would be compromised. It was recommended that a cantilever in the maxilla not exceed 10 mm due to the unfavorable type of bone for support. The upper model was mounted on a milling machine and the infrastructure was waxed up directly to the implant analogues. A bredent preformed plastic bar and modeling resin was utilized to fabricate the substructure. Holes were drilled in the predetermined locations and the ball attachments were positioned with a parallel mandrel. A 10 mm bilateral cantilever was used to get additional support from the implants. The waxed patterns were invested and cast using a semi-precious high palladium alloy (250HV) Afterward in the lab the cast bars were secured to the master model and then milled using a 1.5 mm, 0 degree milling bur at 15,000 rpm to correct the divergent angle. After polishing, the yellow SG retention sleeves are placed on the metal ball attachments and the model is blocked out for duplication for a casting . A 24 gauge leaf wax with retention beads was placed on the refractory model. Afterward it was silicoated and opaqued. Next the upper denture was invested, processed, recovered and polished to completion. The lower over denture is completed with Bredent universal implant abutments. Both restorations satisfied the treatment plan objectives. In conclusion there are numerous benefits in using this kind of anchorage system. The retention sleeves experience intra oral wear and can be replaced at chair side. Ball stud placement whether labial or lingual of the implant bar will only be affected by the aesthetic requirements. In any event, team effort and a co-operative spirit can over come many restorative complications. Source; Peter T. Pontsa RDT
The 10 / 20 rule for complete dentures begins at the incisal line. The upper central incisors are placed starting 10 mm from the center of the incisal papilla and 20 mm down from the vestibular height. Use judgment for placement of the maxillary central incisors, then place the rest of the teeth by following the contour of the ridge. Place the anterior mandibular teeth to verify the phonetics. The incisal guidance is done first. Lingualized occlusion is required and also recommended by implant manufacturers for implant supported dentures. For non supported dentures lingualized denture teeth allow the lingual cusp to run over the shallow fossa of the opposing teeth or dentition. Using gnathological posteriors such as 20 or 30 degree teeth increases the potential for lateral excursion to cause dislodgement. The 10 / 20 rule can also be used in the fabrication of diagnostic dentures, by setting up the teeth and adjusting for proper phonetics and centric relations. After the denture is processed the patient should wear the denture or dentures for six weeks. During this period the clinician will readjust the tissue bearing area using temporary impression material. When the patient is satisfied with the fit and function, the denture should be reprocessed. For completing the final denture the diagnostic denture is mounted on a reline jig with the teeth firmly planted in plaster to leave a matrix. The denture is removed and the 14 teeth should be carefully separated in one section from the diagnostic denture. Then the teeth are placed back in position on the reline jig. Wax the denture to the new natural matrix created over the last six weeks and process the new denture. It is a wise practioner who at the time of the try-in asks the patient to bring to the office a member of the family or a close personal friend to observe the tooth arrangement and give advice. The technique and process has been used quite successfully in many practices across the United States. Source; Dr. Turbyfill American Prosthodontic Society, Feb. 26th, 1996.
When fabricating immediate dentures it is understood they are not too forthcoming, so copying tooth form can usually be hampered. Photographs or snap shots will be valuable as to size of teeth in relation to the face and will define tooth arrangement. In selecting teeth try not to use the teeth as thy come from the card. Always use “staggered “shades. Select cuspids several shades darker than the incisors also make sure the cuspids have labio lingual bulk for a prominent look. Use central incisors with slightly different shading as you are trying to make these teeth look like natural teeth. In the middle aged, natural teeth show a marked variation in color from tooth to tooth. All that is needed is six to eight moulds of teeth and that should cover practically all the needs of a complete denture service. We should not make the process too complicated since nature puts ovoid teeth in square faces and tapered teeth in ovoid faces and so can you. The factor of family has been a great help in working out aesthetic problems. A daughter, son, sister or other relative who bears some resemblance to the patient is used as a model. If you don’t have old photos or a family member try the following formula. 1 Select teeth of adequate size. 2. Have the centrals dominant and have laterals of different moulds. 3. Use the incisive papilla as a guide and set the centrals “forward” of the papilla. 4.Follow the arch form as a guide in setting the remaining teeth. Finally the return of self- confidence, the pride in appearance of the patient are welcomed when the restorations are enthusiastically accepted. Source; Dr. G. Smutko, American Prosthodontic Society, Feb. 26th 1996
The hands on Milling Course will introduce basic milling techniques in combination with the Vario Soft III Attachment from Bredent. It will take place Nov, 9th and 10th at Lab Dentaire I’Outaouais, 1620 Chemin Pink Rd., Aylmer, Québec. Close to Hull and the Ottawa region. The fee is $ 450.00 CAD and 24 CDTO continuing education will credits apply. The next Milling Course will be in Toronto in February 2003. Participants can pre register for this course now.
June 8th & 9th, 2002 Milling Course:
Milling Course ParticipantsDent-Line of Canada Inc. is pleased to present the participants who attended the Bredent Milling and Attachment hands on course June 8 and 9th, 2002 at George Brown College. Peter T. Pontsa RDT introduced them to basic milling and attachment techniques as well as the theory behind the procedures.
Cocaine was widely used as a local anesthetic after Carl Koller demonstrated its effectiveness in 1884. The addictive properties of cocaine were recognized and doctors decided to synthesis it for practical use. The first successful substitute was stovaine discovered in 1904 by Earnst Fourneau. Soon it was followed in 1905, by procaine, discovered by Alfred Einhorn who gave his substance the trade name of Novocain from the Latin novus. Introduced by Heinrich Braun in 1905 novocain soon showed its positive effects without the drugs drawbacks. Guido Fisher popularized Novocain in the U.S. Injected by needle Novocain immediately became popular as a local anesthetic for both medical and dental purposes. Other similar synthetic substitutes for cocaine produced after novocain include tropocaine, aucaine, monocaine and lignocain. Source; World of Scientific Discovery. Gale (1994)