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Prosthodonticstowntownie clinical

Simple, Cost Effective OverdentureWith Implants

Implants have become the state-of-the-art form in today’s den-tistry, particularly in the treatment planning and fabrication of fulldentures. Although many practitioners claim they can make a reten-tive mandibular denture, most of us can’t achieve that kind of resulton a consistent basis and have to deal with never ending adjust-ments and unhappy patients. An unhappy patient has yet to beencountered with lower dentures retained by implants. The timehas come where we can offer dental implants to all our edentulouspatients. Patients who are edentulous in the mandible seem toalmost always present with quality symphyseal bone that will acceptimplant placement which makes most, if not all mandibular eden-tulous patients, good candidates for implant dentistry. Even thosepatients who have some kind of medical compromise may qualifyfor this treatment modality.

There are basically two ways of restoring the edentulousmandible with implants and a removable overdenture. A bar thatsplints the implants, and non-splinted implants with attachmentsplaced directly into the implants. One must visualize the end resultwhen planning mandibular implant retained restorations and carefulassessment of vertical dimension and freeway space are essential toevaluate the design of splinted bars as well as the selection of the dif-ferent types of implant attachments. It is wise to follow all denturefabrication steps and take the prosthesis at least to the wax-try-instage to determine how many implants will beneeded, where they will be placed, and if therewill be enough room for a splinted framework.Measuring from the crest of the ridge, a mini-mum of 13 mm is needed for a mandibularimplant restoration that comprises a framework,and anywhere from 8 mm-10 mm for one that isretained by attachments within the implant.Once this is determined, the case becomes muchsimpler to do both for the surgeon and for therestorative dentist. All that is left to do is duplicatethe prosthesis and fabricate a surgical stent,according to the teeth in wax. Many restorativedentists have found that non-splinted implantswith attachments survive as well, and in somecases, better than splinted ones.

When implants are splinted, a large percentageof the load is placed on the fixtures even thoughthe restoration is tissue borne. Non-splinted

implants with their attachments rely mainly on tissue support. It ismuch easier to evaluate the tissue support of an overdenture on indi-vidual implants than it is on splinted ones, unless sufficient space isprovided by the laboratory within the denture where the splinted barlies and this is usually not the case. Although the jury is still out, mini-dental implants are rapidly becoming part of everyday edentulousdentistry, but at least four of these marvelous implants are recom-mended for a mandibular overdenture. Experience demonstrates thatonly two implants provide sufficient retention for a well-fabricatedball attachment overdenture. Four conventional implants with ballattachments provide excessive retention most of the time and threeborders on too much. In fact, there are many cases where the deacti-vation of two attachments in a four conventional implant restorationhas been needed due to excessive retention. The Dalbo ball attach-ment system provides the restorative dentist some leeway in thisrespect because the system allows for retention adjustments after thehousings are picked up in the overdenture.

Several implant designs are fortunately available today as well aschoice of attachments. In this article, a mandibular implant restorationwith Camlog implants will be addressed along with Dalbo attachments.

This patient is a 54-year-old female who requested dental treat-ment because her teeth didn’t feel right and she had been in pain forseveral years and unable to chew. Inability to masticate is creating

gastrointestinal problems. She is otherwise ingood health and presents with advanced general-ized chronic periodontitis. Tooth migration, lossof vertical dimension, and infection is obvious aswell as the lack of self-esteem. Conversing withthe patient revealed family problems and finan-cial burden. It was decided to do the case gratisin gratitude and for the love of dentistry.

The panoramic x-ray reveals the advancedloss of bone and rampant calculus (Fig. 1).

Pathologic migration, tenacious calculus andinflammation have been a part of this patient’slife for many years (Fig. 2). After careful analysisit was decided that preservation of teeth was notin the best interest of this patient and totalremoval was recommended with concomitantplacement of two Camlog Root Line implants inthe mandible to provide this first time dentureuser a chance for quick adaptation (Figs. 3 & 4).

Dr. Julio Maya

Fig. 2

Fig. 1

39dentaltown.comApril 2005

Careful debridement and alveoplasty was done with a mental pic-ture of what the ideal ridge should look like after healing takes place.

A midline incision provided access to the apical bone withoutthe need for manual retraction of the gingival tissue, for the imme-diate placement of the implants and to obtain tension free primaryflap closure for these implants. The sockets were purposely left openwith the intent to obtain a wide ridge while the bone regenerateswithin the socket. Most surgeries use a split thickness flap, whichkeeps the periosteum in place and provides proper blood supply forthe bone and tissue, also allowing for proper tissue handling andplacement. Healing therefore is quicker with less discomfort.

Three days post op revealed excellent responseto the elimination of insult to the gingival tis-sues, a sign that edentulation was appropriatefor this patient. The sutures were removed atthree days, as there was no movement of the tis-sue upon pressure.

At three months (Fig. 5), the implants canbe seen through the healthy gingival tissue. Thealveoplasty created a wide well rounded ridge.

Attached thick gingival tissue is always a pluswhen implants are involved. In this case, therewas very thin labial attached tissue present so alingual incision was made in order to roll the tis-sue buccally and provide keratinized gingiva forthe implants (Fig. 6). The release incisions helpin the sense that the tissue can be manipulatedeasier and without trauma.

Once the tissue has been rolled to the buc-

cal, notice how the former crestal gingiva, now the buccal gingiva,hugs the healing abutments (Fig. 7). This simple procedure guar-antees attached thick tissue on the labial as well as the lingual, afeature that is desirable in implant dentistry.

Healthy implants surrounded by healthy tissue are indicative ofthe application of sound surgical principles (Fig. 8).

Normal prosthodontic impression procedures are undertaken.All edentulous patients require two impressions, as follows:1. Fabrication of a good custom tray 2-3 mm short of the bor-

ders is of paramount importance with this technique.2. Medium body Polyvynilsiloxane impression material is

used for the first impression applying positivepressure, and the borders are molded.

3. Removal of 1.5-2 mm of the mediumbody is done to create space.

4. A wash impression with light body istaken, and border molding is done again.

Mounting consists of a face bow transfer. Blockout of the healing abutments and creation of spacefor the ball abutments is done at this stage.

Set up and wax-up are done for the try-inappointment and after the patient and the doctorare satisfied, the dentures are processed (Fig. 9).

The laboratory is instructed to relieve theimplant sites (Fig. 10).

Placement of the Dalbo ball abutment is eas-ily done at the final appointment. The fixture isvisible and confirms implant placement proto-col with one of the cams facing the buccal.

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One of the advantages of the Camlog abutment system is themassive abutment screw of the design. They are easily torqued byhand well beyond 10Ncm. These Dalbo abutments were torquedto 30 Ncm (Fig. 11).

Once the torque driver’s head breaks, theattachment is properly torqued (Fig. 12).

Pick up of the attachment housings should bedone chairside so a totally passive fit within theoverdenture is obtained, therefore the housingsmust be positioned on the abutments, the over-denture must be tried in and the patient guidedto intercuspation without interfering with the

attachments (Fig. 13). The white spacers keep the housings frommoving laterally and are very stable. The size of the housing is 2.65mm. The abutments vary in size from 1.5 mm, 3.0 mm and 4.5 mm

After lubricating the abutments, GC patternresin is used to pick up the housings because ofits rapid, rock hard set (Fig. 14). The distinguish-able red color aids in the removal of excess resinfrom the inside of the denture. The retention ofthe attachments can be adjusted by screwing theretention inserts in or out with the Phillips style driver included in the Dalbo kit, a very use-ful feature.

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Fig. 14

Fig. 11 Fig. 12 Fig. 13

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The use of lingualized occlusion is the first choice in implantreconstructions, where only the palatal cusps engage the centralfossae of the mandibular teeth. The stability of the denture, chew-ing ability, and the process of deglutition are enhanced (Fig. 15).

There’s nothing like making someone’s life considerably betterthrough the art form of dentistry. The satisfaction in this case istotal. Finances didn’t play a roll in treatment; the office paid foreverything and the euphoric smile is an emotional reward (Fig. 16).It was the purpose of this treatment to give back to dentistry andto humanity what has always prevailed in our profession, kindness.

These cases are straightforward, fun and cost effective for thept. There didn’t seem to be any difference with the retention or sta-bility of the overdenture with the more spaced implant placementas shown in this case when compared to the first one.

Dr. Maya is a 1981 graduate of the University of Puerto Rico Dental School. He has been in private practice inTampa for the last 21 years and enjoys practicing reconstructive dentistry. He was past president and charter member ofthe Tampa Implant Study Club. He has elected to practice a sport that resembles Dentistry in that perfection can neverbe achieved, one can only strive for perfection, Golf.

Fig. 15 Fig. 16

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