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INTRODUCTIONSmall-diameter implants (SDIs) have be -come an efficient tool for denture andremovable partial denture stabilization, aswell as some specific fixed restorative situa-tions. One downside of SDI utilization hasbeen the prolonged healing time necessaryprior to SDI placement following toothextraction. The following article details amethod for immediate SDI placement in theinterproximal bone following the extrac-tion of mandibular anterior teeth.

BACKGROUNDA patient with an otherwise unremarkablemedical history presented to the author’soffice in poor oral health, with extensivedecay and partial edentulism throughout theupper and lower arches. The time and cost ofthe restorative process were a concern forthis patient. The author presented 3 treat-ment options involving a variety of endodon-tic, restorative, implant, and/or prostheticprotocols. Given the opportunity to choose,the patient selected an option that called forextraction of her remaining teeth, a remov-able maxillary denture, and an SDI-support-ed removable mandibular denture. An in -creasingly common tool in clinical practice,SDIs offer a lower-cost, simpler alternativecompared to standard-width implants.1

The literature supports these aforemen-tioned uses in clinical practice. In theirreview of 41 studies, Sohrabi et al2 conclud-ed that SDIs have success rates similar totheir traditional-width counterparts and canserve as a viable option to retain fixed pros-thetics or mandibular overdentures in cer-tain patient populations. A biometric analy-sis by Bulard and Vance3 of 1,029 SDIs up to8 years in vivo demonstrated their effective-ness in long-term prosthetic stabilization,and a study by Shatkin et al4 noted a 94.2%overall success rate of SDIs used in supportof prosthetics, with improved placementtechniques affecting outcome.

CASE REPORTDiagnosis and Treatment Planning

A 38-year-old female in otherwise good healthpresented with partial edentulism and severedecay of most of her remaining teeth (Figures1a to 2b). After a full clinical and radiographicexamination, the author developed 3 poten-tial treatment options to discuss with the pa -tient at the consultation appointment. They

were as follows: (1) full-mouth reconstruc-tion with selective tooth extraction, endodon-tic therapy, root form implants, periodontalsurgery, full crowns, and porcelain veneers;(2) full-mouth extraction with fixed maxil-lary and mandibular restorations (All-on-Four);1,5 and (3) removable denture stabiliza-tion with root form or SDIs. The patient chose a treatment plan that

included full-mouth extraction with re -movable dentures and SDI stabilization of themandibular denture. A maxillary immediatedenture would be placed at the time of toothextraction. SDIs would be immediately placedin the interproximal bone of the mandibularanterior region at the time of tooth extraction.The mandibular extraction sites would bebone grafted and covered with a resorbablemembrane. A mandibular denture would beconstructed 3 months post-extraction.

Clinical ProtocolImpressions of the maxillary and mandibu-lar arches, along with a face-bow record,were taken at the examination appoint-ment for pre-extraction fabrication of amaxillary removable denture. At the first treatment appointment, the

patient was sedated, and her remainingmaxillary and mandibular teeth wereextracted. Care was taken to remove theteeth vertically, preserving the buccal bonyplates. The maxillary teeth were extractedfirst so that the immediate maxillary den-ture could be fitted to the occlusion of themandibular teeth, preserving both generalpreoperative occlusal planes and verticaldimension (Figures 3 and 4). The maxillaryimmediate denture was relined with softliner (3M ESPE). Fixodent powder (Procter& Gamble) would be used to further securethe maxillary immediate denture duringthe 3-month healing phase.Following extraction of the mandibular

teeth, an incision was made and reflected toexpose the wedge-shaped interproximalbone. The bone was then recontoured using

Steven T.Cutbirth,DDS

Immediate Mini ImplantPlacement Following Extractions

continued on page 102Figures 1a to 2b. The patient presented with severe decay, worn restorations, and partial edentulism.

IMPLANTS

One downside of SDI utilization has been the prolonged healing timenecessary prior to SDI placement following tooth extraction.

1a 1b

2a 2b

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a sterile, coarse, football-shaped dia-mond bur (No. 5379 023 [BrasselerUSA]) to create flat platforms for SDIplacement (Figure 5). Only minor bonerecontouring was necessary. Note thatit is important to insert the SDIs intoa flat surface, and recontouring theinterproximal bone to create theseplatforms maximizes long-term sta-bility and periodontalhealth. Small-diame-ter im plants require10.0 mm of verticalbone height, but canbe placed in bonewidths as narrow as3.0 to 4.0 mm facial-lingually, with ap -proximately 1.0 mmof bone surroundingthe implant.1Four 1.8 x 13 mm

SDIs (MDI Mini Den tal Im plants [3MESPE]) were placed in the flat plat-forms created in the interproximalbone. The cortical plate was firstpierced with a pilot drill, then theimplants were screwed through thecortical plate and into the trabecularbone with a finger driver, followed bya winged wrench (the ratchet wrenchmay also be used if the patient cannotopen the mouth sufficiently to allowenough vertical space for the wingedwrench) (Figures 6 to 9). The extrac-tion sockets were grafted with sterilexenograft bone (Bio-Oss 1.0 to 2.0 mmcancellous granules [Geist lich Bioma -terials]) and covered with a re sorbablemembrane (BioCellect [IM TEC, a 3MCompany]) (Figures 10 and 11). The important point with this

procedure is that the fully insertedimplants may not be turned with fullfinger pressure on the finger driver; ifthe finger driver can be used to com-pletely insert the implant, the SDIlikely will not osseointegrate fullyand will fail. It is also important thatthe implants make a “ting” soundrather than a “thud” when tappedwith a dental mirror handle. As previously mentioned, there

should be at least 1.0 mm of bone onthe facial and lingual aspect of theimplants. If there is less than 1.0 mmbone on the facial, additional bonegrafting on the facial surface shouldbe considered. There will often not be1.0 mm of bone on the coronal onequarter to one third of the mesial anddistal aspect of the implants. Theinterproximal bone almost alwaysbecomes wider mesialdistally as theimplant is advanced apically, so at

least the apical three quarters of theimplants should be completely sur-rounded by at least 1.0 mm bone. Themesial and distal bone will fill in asthe extraction sockets heal.The periodontal flap was sutured

passively with 3-0 chromic gut (Ethi -con) (5-0 polypropylene suture (PRO-LENE [Ethicon 360] can also be used)(Figure 12). The author currently

prefers the chromic gut suture be -cause it dissolves after 2 weeks invivo. PROLENE, however, does notdissolve, and the healing tissue oftengrows over the suture, making it dif-ficult to remove after one to 2 weeksof healing. If the patient has an activelower lip, a portion of these cases willrequire resuturing part of the flapone to 2 weeks postoperatively due to

lower lip movement. This postopera-tive tissue separation will not affectthe outcome of the case, but thepatient should be advised preopera-tively of the potential necessity ofthis resuturing procedure.The mandibular ridge was al lowed

to heal for 3 months following implantplacement and bone grafting with a

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Figures 3 and 4. The maxillary teeth were extracted, and a maxillary denture was fabricatedand fitted to the occlusion of the lower arch.

Figures 6 to 9. The cortical plate was pierced with a pilot drill (Figures 6 and 7), and the implants were screwed in with a finger driver (Figure 8), followed by awinged wrench (Figure 9).

Figure 5. A coarse, football-shaped diamondwas used to flatten the mandibular interproximal bone.

Figure 12. The periodontal flap was suturedwith 3-0 chromic gut.

Figures 10 and 11. Bio-Oss sterile xenograft bone granules (Geistlich Biomaterials) wereused to graft the extraction sockets (Figure 10). The graft was covered with a BioCellect(IMTEC, a 3M Company) resorbable membrane (Figure 11).

Figures 13a and 13b. The mandibular ridge was allowed to heal for 3 months post-extraction, implant placement, and grafting.

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Immediate Mini Implant Placement...

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If there is less than 1.0 mm bone on the facial, additional bone grafting on the facial surface should be considered.

Figure 14. The housings, o-rings, and greenblock-out shims were placed on theimplants, then pulled into a custom traypolyether impression.

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resorbable membrane (Figures 13a and13b). Denture construction then beganwith a custom tray impression. Thehousings and o-rings, with green block-out shims, were placed on the implantsand pulled in the custom tray poly-ether impression (Figure 14). The hous-ings are used by the dental laboratoryteam from the beginning of denturefabrication, to ensure appropriatespace in the denture for the housings.A wax rim and baseplate try-in fol-lowed (Fig ure 15), then the teeth-in-wax appointment and denture delivery.The housings and o-rings may be

processed in the denture by the labora-

tory or pulled with a hard in-office re -line acrylic (Hard Liner SECURE HardPick-Up Kit No. 8720 [3M ESPE]). Theauthor prefers to pull the housings in-office at the delivery appointment. Thisensures that the denture is supported

vertically by the bony ridge and soft tis-sue, not the implants. If the denture piv-ots on an implant when the patientbites down, there is a high probabilitythe denture will fracture along a lineover that implant. It is not possible to

confirm that all hous-ings are ideally seatedon the implants, orthat the denture isfully supported verti-cally by the bonyridge and soft tissue, ifthe housings are pro -cessed by the dentallaboratory team priorto denture seating. Im -plants are intended tosupport dentures and

removable partial den-tures horizontally andto resist coronal uplift-ing; they are not in -tended to serve as ver-tical denture support.To pull the hous-

ings in-office at thedenture delivery ap -pointment, the fol-lowing procedure isemployed:

1. Place the hous-ings with o-rings onthe implants. Placegreen block-out shimson the necks of the im -plants between thehousings and the softtissue (Figure 14).

2. Try the den-ture in over the hous-ings. Be certain thereis more than enoughspace (housing “holes”)created on the tissueside of the denture to

accommodate the housings when thedenture is seated firmly with operatorfinger pressure. The housings mustnot touch the denture during thepick-up process or they will distort.

3. Place adhesive in the housingholes in the denture.

4. Place Vaseline on the denturearound the housing holes to prevent thepick-up material from adhering to anyareas of the denture except the holes.

5. Administer flowable hard pick-up material (3M Hard Liner SECUREHard Pick-Up Kit No. 8720) into thehousing holes in the denture. It is notnecessary to administer pick-up mate-rial onto the housings in the mouth.

6. Place the denture over thehousings and mandibular ridge and

hold in place with operator fingerpressure (Figure 16). Firm pressureshould be applied, similar to the pres-sure applied when the patient is bit-ing. Firm patient biting pressure isthe force that will fracture the den-ture if the denture pivots on animplant and is not supported verti-cally by the bony ridge and soft tis-sue. It is important that the operatorhold the denture in place with one’sfingers and thumbs as opposed to thepatient biting the denture to placewith the opposing teeth. If the occlu-sion is not ideal, the denture mighttorque if biting pressure is utilized toseat the denture on the housings.This torqueing would cause the den-ture to not be seated firmly on the tis-sue/bony ridge throughout the arch,creating denture instability.

7. Once the hard pick-up materialhas set completely, remove the den-ture and remove the excess pick-upmaterial with an appropriately sizedacrylic bur (Brasseler USA), then pol-ish (Figure 17). A long shank No. 8

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Immediate Mini Implant Placement...

Figure 15. A wax rim and baseplate try-infollowed.

Figure 16. The denture was placed over thehousings and mandibular ridge and held inplace with operator finger pressure.

Figure 17. Polished denture base with housings set in place.

Once in-office procedures are complete and the patient is satisfied with the result, homecare should be reviewed carefully.

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round bur is effective in removingany excess material covering the sil-ver platforms of the housings. Alsoround any sharp line angles in thepick up acrylic, but be sure not toremove the hardened pick-up materi-al interproximal to the implants. Ifthere are any voids in the acrylic,additional hard pick-up material orgingival colored flowable composite(LuxaFlow [DMG America]) may beused to fill those areas.

8. Check the occlusion carefullywith occlusal indicator paper (BauschArti-Check Articulating Pa per). Formaximum denture stability, it is im -portant the teeth occlude simultane-ously on both the right and left sideson the bicuspids, cuspids, and mesialof the first molars with the condyles incentric relation position. Check theocclusion with the patient in the “alertfeeding position” (AFP), ie, sittingstraight up in the operatory chair, toensure the anterior teeth do not con-tact prior to the posterior teeth whenthe patient bites down. Light pressureshould be ap plied to the chin with thedentist’s hand in a distal direction tocheck the AFP. This light pressure onthe chin allows the upright patient tomove the mandible forward slightlywhen closing, also referred to as free-dom in centric, but prevents movementinto a full protrusive position.Final photos of the patient can be

seen in Figures 18 to 19b. She waspleased with the comfort, fit, function,and appearance of her maxillary den-ture and implant-retained mandibulardenture. She can now speak and eatwith confidence, without pain, and herself-confidence has improved with hernew, healthy smile.

DISCUSSIONNormally, a custom maxillary denturewould be fabricated along with themandibular, SDI-supported denture.In this case, the patient was contentwith the esthetics and fit of the imme-diate denture, so a second denture wasnot fabricated. Once in-office proce-dures are complete and the patient issatisfied with the result, home care

should be reviewed carefully. Ideally,the patient should not wear the den-tures while sleeping, in order to allowthe tissue to rest. The dentures may besoaked in a denture cleaner overnightand brushed with a denture brush andsoap several times aweek. Oc casionally, av a c u um - f o rm e dnightguard needs tobe fabricated to coverthe im plants if thepatient is a bruxer.

CLOSING COMMENTS

The patient treated inthe above case reportpresented for treat-ment, having enduredyears of dental decay,teeth pain, missingteeth, and an unattrac-tive smile. The authorof fered her a numberof options for treat-ment, keeping inmind the patient’sfinancial, time, andquality of life con-cerns. The solutionshe chose (a maxillarydenture and SDI-re -tained mandibularden ture) provided herwith the attractive,healthy, functional,and comfortable den-tition that she hadalways desired.�

References1. Christensen GJ. Ask Dr.

Christensen. Dent Econ.2011;101:54-56, 90.

2. Sohrabi K, Mushantat A,Esfandiari S, et al. Howsuccessful are small-diam-eter implants? A literaturereview. Clin Oral ImplantsRes. 2012;23:515-525.

3. Bulard RA, Vance JB. Multi-clinic evaluation usingmini-dental implants forlong-term denture stabi-lization: a preliminary bio-metric evaluation. Com -pend Contin Educ Dent.2005;26:892-897.

4. Shatkin TE, Shatkin S,Oppenheimer BD, et al.

Mini dental implants for long-term fixed andremovable prosthetics: a retrospective analysisof 2514 implants placed over a five-year period.Compend Contin Educ Dent. 2007;28:92-99.

5. Malo P, de Araújo Nobre M, Lopes A, et al. A lon-gitudinal study of the survival of all-on-4implants in the mandible with up to 10 years offollow-up. J Am Dent Assoc. 2011;142:310-320.

Dr. Cutbirth practices restorative dentistry inWaco, Tex (wacosedationdentist.com), and isdirector of the Center for Aesthetic RestorativeDentistry (CARD) (centerforard.com), located inDallas, Tex, a hands-on, complex restorativeteaching center for practicing dentists. Hegraduated from Baylor Dental College in 1979,then completed a 2-year fellowship at Baylor,then was a member of the teaching faculty atthe Pankey Institute in Florida for 20 years. Dr.Cutbirth has lectured and published extensive-ly on the topics of systematic restoration of theseverely worn dentition with vertical dimensionincrease, diagnosis and treatment of occlusalproblems and facial pain, complex estheticrestorative dentistry, ridge modification andbone grafting for small-diameter implant uti-lization, and the most effective/productive den-tal practice system. He can be reached at(254) 772-5420 or at card1611@gmail.com.

Disclosure: Dr. Cutbrith is an occasional lectur-er for 3M ESPE but has received no compen-sation for the writing of this article.

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Figure 18. Lower implant-retained denture inthe mouth.

Figures 19a and 19b. The final dentures are pictured in occlusion and smile poses.

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