Original Source

Small-Diameter Implant Treatment Plan Revision: Management of Complications

Brian J. Jackson, DDS*


Small-Diameter Implant Treatment Plan Revision: Management of Complications

Brian J. Jackson, DDS*

Implant dentistry has become a predictable discipline for reconstructing the edentulous patient. The edentulous population in the United States will increase over the next 3 decades, and the demand for implant-supported prostheses will rise accordingly.1 Maxillary and mandibular implantretained overdentures may serve as an acceptable treatment option for the rehabilitation of the edentulous patient.2,3 Conventional implants are the primary type and diameter size used in reconstruction, however small-diameter implants (SDI) or mini-dental implants (MDI) may play a role in specific indications.

Survival rates for small-diameter endosseous implants demonstrate a mean success rate of 94%, although complications and failures have been reported.4,5 Reasons for less than ideal outcomes are poor diagnosis and treatment planning, inadequate bone quality/quantity, implant design, early/late loading, prosthetic design, and biomechanical factors related to implant occlusal concepts.6

This case letter describes a mini-implant failure and the subsequent management of complications and oral reconstruction for the edentulous patient with removable overdentures.

Small-diameter implants have received Food and Drug Administration approval for long term use for overdentures, removable partial dentures, and fixed multiunit bridges.7 Smalldiameter implants are a 1-piece, single-stage implant manufactured from titanium alloy. They are composed of an intraosseous, transgingival, and o-ball prosthetic component. It is essential that strict surgical and prosthetic protocols are followed or less than ideal outcomes can be realized.9


A 41-year-old white man presented at a private practice with a concern about the status of his failing MDI.

The patient’s medical history revealed (1) gastric bypass surgery, (2) hypertension, and (3) the following medications: testosterone, lisinopril, vitamin D, and vitamin B12. The patient reported that 2 years earlier, 5 MDI were placed in the maxilla and 5 in the mandible and immediately loaded. The patient stated that in the maxilla, 2 implants failed, and of the remaining 2, 1 was loose and 1 painful. The patient stated that he was satisfied with the mandibular implants.

A clinical examination revealed 3 SDI present in the maxilla

and 5 SDI in the mandible (Figures 1 and 2). The implant in position No. 9 was mobile, and No. 10 was sensitive to percussion. All tissue proximal to the implants indicated varying degrees of erythema, edema, and bleeding on probing. The mandibular implants were asymptomatic; however, the implant in position No. 24 exhibited severe lingual divergency. The prostheses were removable overdentures with o-ring attachments (Figure 3). The prosthetic occlusion demonstrated anterior tooth contact with bilateral posterior dissocclusion in centric relation and a reduced vertical dimension of occlusion with excessive overjet and overbite (Figures 4 through 6). The radiographic survey demonstrated reduced crestal bone levels associated with the mini-implant in the left maxillary incisor position (Nos. 9, 10; Figure 7). On the basis of the clinical and radiological examination, a primary diagnosis was made of periimplantitis (implants 9 and 10) and a maladaptive occlusal scheme.

Initial therapy focused on the removal of the implant in position No. 9 and the modification of the existing prosthesis to establish a posterior occlusion. Anesthesia was administered, an SDI-specific thumb wrench instrument placed over the prosthetic head, and a reverse manual torque applied in a counterclockwise direction to remove the implant. The residual site was debrided and grafted with a mixture of platelet-rich plasma (PRP) and mineralized irradiated cortical cancellous allograph (Puros, Zimmer, Carlsbad, Calif; Figures 8 and 9). Resin was applied to the occlusal surfaces of the posterior mandibular teeth to establish a bilateral posterior occlusion (Figures 10 and 11).

The prosthetic reconstruction was initiated with the fabrication of a maxillary complete denture and a mandibular overdenture. A final mandibular impression using a polyvinylsiloxane material (Imprint III, 3M, St Paul, Minn) placed over the MDI o-ring prosthetic component was performed to capture indirect transfer caps (Figures 12 and 13). A commercial laboratory fabricated an implant working model and a mandibular unibase containing MH2 o-ring housings (Figure 14). A maxillary/mandibular relationship was established, tooth mold (Ivoclar P8), shade (B1) selected, followed by a try-in and final placement (Figures 15 and 16).

The maxillary implant reconstructive surgery was initiated 6 months after the mobile implant was removed (Figures 17 and 18). A 20-mL blood draw from the left medial cubital vein was taken and placed in a single-stage centrifuge. A local anesthetic was delivered, a full mucoperiosteal flap was elevated, and a

Slavin, Jackson & Burns, Utica, NY.

* Corresponding author, e-mail: DOI: 10.1563/aaid-joi-D-15-00083

surgical guide was placed, followed by a 6-mm partial

osteotomy created with a 1.1-mm drill. The SDI were autoadvanced with a finger driver, thumb wrench, and ratchet. The implants placed were (5) 2.4 3 13 mm and (1) 2.4 3 10 mm

Journal of Oral Implantology 295

Small-Diameter Implant Treatment Plan Revision

FIGURES 1–9. FIGURE 1. Initial intraoral—maxilla. FIGURE 2. Initial intraoral—mandible. FIGURE 3. Maxillary overdenture—palateless. FIGURE 4. Initial intraoral—centric relation. FIGURE 5. Initial intraoral—centric relation right. FIGURE 6. Initial intraoral—centric relation left. FIGURE 7. Initial panoramic radiograph. FIGURE 8. Maxilla post MDI removal. FIGURE 9. MDI implant 2.4 3 13 mm.

FIGURES 10–18. FIGURE 10. Centric relation (R)—mandibular resin application. FIGURE 11. Centric relation (L)—mandibular resin application. FIGURE 12. MDI impression transfers. FIGURE 13. Implant analogues/transfers secured in impression material. FIGURE 14. Mandibular unibase with MH2 o-rings. FIGURE 15. Maxillary/mandibular relationship. FIGURE 16. Prosthetic try in. FIGURE 17. Panorex—preimplant surgery. FIGURE 18. Maxilla—prerevision surgery.

296 Vol. XLII/No. Three/2016


FIGURES 19–26. FIGURE 19. Maxilla—final implant placement. FIGURE 20. Maxillary denture—soft reline. FIGURE 21. Maxilla—MH1 housings. FIGURE 22. Maxillary overdenture with MH1 housings. FIGURE 23. Final prosthesis (RT) centric relation. FIGURE 24. Final prosthesis (LT) centric relation. FIGURE 25. Final prosthesis—centric relation (facial). FIGURE 26. Final Panorex.

(3M ESPE, St. Paul, Minn) distributed anterior to the maxillary sinus (Figure 19). The implant prosthetic o-ball heads were relieved in the undersurface of the maxillary denture and relined with a soft silicone material (Figure 20).

After 6 months, MHI design o-ring housings were placed on the o-ball prosthetic attachments, and a hard composite reline material (Secure, 3M ESPE) was placed around the housings and in denture relief areas (Figures 21 and 22). Vertical dimension, centric relation, and all excursive movements were evaluated (Figures 23 through 26).


Small-diameter implants have emerged as an alternative for patients with deficient bone and compromised health histories.10 Research has demonstrated that osseointegration can be achieved with SDI.11 Strict protocols need to be adhered to however, otherwise complications can develop and jeopardize implant survival. It is difficult to determine whether the failure seen in this clinical case is specific to the surgical aspect or the occlusal scheme. However, it can be hypothesized that variances in recommended implant protocols may have negatively affected the results.

Small-diameter implants consist of a 1-piece design manufactured from titanium alloy (Ti 6Al-4V), which increases the strength of the implant.12 The absence of a microgap common to a 2-piece design reduces pathogenic microbe colonization.13 A microthread transgingival design with blasted osseous threads enhances bone and soft-tissue adherence.14,15 The o-ball prosthetic design with an o-ring stainless steel housing complex provides retention for the overdenture.16

A removable overdenture maxillary treatment plan using SDIs should incorporate several considerations: a minimum of 6 implants with 2.4-mm or greater diameter size and length equal to or exceeding 13 mm.17 These specifications increase rigid fixation via bone-to-implant contact. Implants are placed anterior to the maxillary sinus in type I, II, or III quality bone. A 6-month nonloading osseointegrative period allows for enhanced mineralization of bone. In light of the results obtained in this case report, the author advocates a delayed healing period as opposed to an immediate load approach. The maxillary overdenture is stabilized and supported by soft tissue and retained by implants.18 A horseshoe design should be avoided to reduce stress on the implants. The author suggests that if a reduction in the palatal surface is requested, an incremental modification can be achieved after 6 months.

Small-diameter implants in limited situations demonstrate successful results when diagnostic, surgical, and prosthetic protocols are followed. The partial, undersized osteotomy ensures initial rigid fixation in bone. Implant stability is the primary objective at surgical placement. A mucoperiosteal flap or flapless approach can be used. A flapless approach is best achieved with the aid of cone-beam computerized tomography imaging.19 In this case study, the previous implant surgery was performed flapless without the aid of 3-dimensional imagery. It is possible that the implants may not have been completely placed in bone. A comprehensive treatment plan based on

Journal of Oral Implantology 297

Small-Diameter Implant Treatment Plan Revision

sound diagnostic criteria can provide crucial information for safe surgical placement and prosthetic reconstruction.20

Platelet-rich plasma enhances soft- and hard-tissue development through elevated growth factor concentrations.21 Growth factors released from platelets expedite healing and reduce pain and infection rates.22 The main growth factors such as platelet-derived growth factor, transforming growth factor beta-1, epidermal growth factor, and vascular endothelial growth factor, are directly involved in the recruitment, proliferation, and differentiation of cells.23 Research has demonstrated that healing tissues possess higher levels of growth factor concentrations than chronic nonhealing sites.24 The author felt it was critical to use PRP in this case to enhance the healing potential.

Implant occlusal principles should be employed with maxillary and mandibular implant retained overdentures. A bilateral balanced occlusion is developed with simultaneous posterior contact during centric relation and lateral excursions. Protrusive movements maintain posterior contact, while noninterfering contacts are achieved with anterior teeth.25 The forces of occlusion are evenly directed to the alveolar ridges, thereby reducing bone resorption.26 The author reports that the initial occlusion demonstrated a lack of posterior support with all forces applied to the anterior aspect of the overdenture. This design magnifies the stress applied to the implants, encouraging bone resorption and implant failure.


For this case report, small-diameter (,3 mm) implant failure was probably due to poor surgical placement, immediate loading, and poor occlusal design. Small-diameter implants have emerged as a possible solution for patients with deficient bone, compromised health histories, and financial limitations. The conservative body of research regarding SDI has emphasized the importance of strict protocols to ensure predictable outcomes. Complications leading to failures or other less than ideal outcomes can lead to undesirable clinical results. A thought-provoking treatment plan revision can salvage cases and meet patient expectations.


MDI: mini-dental implants

PRP: platelet-rich plasma

SDI: small-diameter implants


The author wishes to acknowledge Caitlin Carparelli, DA, and Tatyana Lyubezhanina, DA, for their assistance in the preparation of this article, and Robert and Matthew Weigand, CDT (Utica Dental Laboratory, Utica, NY), for their dental technical expertise.

298 Vol. XLII/No. Three/2016


  1. Douglas CW, Shih A, Ostry L. Will there be a need for completedentures in the United States in 2020? J Prosthet Dent. 2002;87:5–8.
  2. Jemt T. Implant treatment in resorbed edentulous upper jaws: athree-year follow up on 70 patients. Clin Oral Implants Res. 1993;4:187–194.
  3. Smedberg JI, Lothigius E, Bodin I, et al. A clinical and radiologicaltwo-year follow up study of maxillary overdentures on osseointegrated implants. Clin Oral Implants Res. 1993;4:39–46.
  4. Shatkin TE, Shatkin S, Oppenheimer BD, et al. Mini dental implantsfor long-term fixed and removable prosthetics: a retrospective analysis of 2514 implants placed over a five-year period. Compend Contin Educ Dent. 2007;28:92–101
  5. Esposito M, Hirsch J, Lekholm U, Thomsen P. Differential diagnosisand treatment strategies for biologic complications and failing oral implants: a review of the literature. Int J Oral Maxillofac Implants. 1999;14:473–490.
  1. Esposito M, Hirsch J-M, Lekholm U, Thomsen P. Biological factorscontributing to failures of osseointegrated oral implants. (II) Etiopathogenesis. Eur J Oral Sci. 1998;106:721–764.
  2. Christensen GJ. The ‘‘mini’’ implant has arrived. J Am Dent Assoc. 2006;137:387–390.
  3. Sendax V. Mini Dental Implants: Principles and Practices. St Louis, Mo: Mosby; 2013.
  4. Bulard RA, Vance JB. Multi-clinic evaluation using mini dentalimplants for long-term denture stabilization: a preliminary biometric evaluation. Compend Contin Educ Dent. 2005;26:892–897.
  5. Davarpanah M, Martinez H, Tecucianu JF, Celletti R, Lazzara R.Small-diameter implants: indications and contraindications. J Esthet Dent. 2000;12:186–194.
  6. Balkin BE, Steflik DE, Naval F. Mini-dental implant insertion with theauto-advance technique for ongoing applications. J Oral Implantol. 2001;27: 32–27.
  7. Titanium and titanium alloys. In: Campbell FC, ed. Elements of Metallurgy and Engineering Alloys. Materials Park, Ohio: ASM International; 2011.
  8. Siepenkothen T. Clinical performance and radiographic evaluationof a novel one-piece implant in a private practice over a mean of seventeen months. J Prosthet Dent. 2007;97:569–578.
  9. James RA, McKinney RV, Meffert RM. Tissue surrounding dentalimplants. In: Misch CE, ed. Contemporary Implant Dentistry. 2nd ed. St Louis, Mo: Mosby; 1999:239–251.
  10. Wennerberg A, Albrektsson T, Anderson B, Krol JJ. A histomorphometric and removal torque study of screw-shaped titanium implants with three different surface topographies. Clin Oral Implants Res. 1995;6:24–30.
  11. Pound E, Murrell GA. An introduction to denture simplification. J Prosthet Dent. 1971;26:570–580.
  12. Jackson B. Small-diameter implants: a treatment consideration forthe maxillary edentulous patient. Dentistry Today. 2013(November):86–92.
  13. Lemmons JE, Bidez MW. Biomaterials and biomechanics in implantsdentistry. In: McKinney RV, ed. Endosteal Dental Implants. St Louis, Mo: Mosby Year Book; 1991.
  14. Orentilcher G, Goldsmith D, Abboud M. Computer guided planningand placement of dental implants. Atlas Oral Maxilofacial Surg Clin North Am.


  1. English CE. Critical A-P Spread. Implant Soc. 1990;1:2–3.
  2. Frechette J-P, Martineau I, Gagnon G. Platelet-rich plasmas: growthfactor content and roles in wound healing. J Dent Res. 2005;84:434–439.
  3. Marx RE. Platelet-rich plasma: evidence to support its use. J Oral Maxillofac Surg. 2004;62:489–496.
  4. Shah S, Keppler L, Rutkowski J. A review of platelet derived growthfactor playing pivotal role in bone regeneration. J Oral Implantol. 2014;40: 330–340.
  5. Pierce GF, Mustoe TA, Ingelbach J, et al. Platelet-derived growthfactor and transforming growth factor-beta enhance tissue repair activities by unique mechanisms. J Cell Biol. 1989;109:429–440.
  6. Payne SH. A posterior set up to meet individual requirements. Dent Digest. 1941;47:20–22.
  7. Brunski JB. In vivo bone response to biomechanical loading at thebone/dental-implant interface. Adv Dent Res. 1999;13:99–119.

Leave a Reply

Implant Planning Using Ez3D-i and Ez3D Plus...

December 7, 2017 — Dental Implants

Dr. Timothy Kosinski utilizes 2D and 3D imaging to place two implants in the maxilla, numbers 7 and 10. He utilizes Ez3D-i, Vatech's newest 3D imaging software. Starting from the...

Creating Synergy with Conventional and Small-Diameter Implants

November 14, 2017 — Dental Implants

Planning for success with maxillary and mandibular overdentures. The demand for implant-supported dentures is projected to increase in coming years

Dental Treatment: Fixed Detachable Prosthesis

November 13, 2017 — Dental Implants

As the population ages worldwide, individuals with hopeless teeth or who are completely edentulous will increase. The fixed detachable prosthesis is a predictable implant approach to manage several ages of...

Not a Member yet? Sign up for Free

Get Started