Titanium Tattooing Associated with Zirconia Implant Abutments: A Clinical Report of Two Cases Thomas D. Taylor, DDS, MSD1/Michael W. Klotz, DMD, MDentSc2/Rodger A. Lawton, DMD3 Worn particulate titanium abraded from a titanium dental implant that discolors the adjacent soft tissues has not previously been reported. Two cases of this gingival tissue “tattooing” are reported here. While the use of zirconia abutments in areas of high esthetic concern is widespread, the effects of particulate titanium being worn from the implant by the much harder abutment material and then taken up in the adjacent soft tissues should be considered as a potential complication and a consideration when selecting the type of abutment to be used. Int J Oral Maxillofac Implants 2014;29:958–960. doi: 10.11607/jomi.3700 Key words: abutment fracture, particulate titanium, titanium tattoo, zirconia abutment
T
he use of zirconium oxide (zirconia) as a restorative material in dentistry has become widespread. Zirconia as an implant abutment material in place of titanium or other metals is primarily indicated in situations where the overlying soft tissue is thin and/or transparent and a metal abutment would cause discoloration of the tissue leading to an esthetic compromise. The use of the zirconia abutment has become commonplace in spite of its narrowly described indication for use in highly visible areas in patients with thin tissue phenotype. Concern has been expressed in the literature regarding the safety and efficacy of mating zirconia restorative abutments with titanium implants.1 Zirconia is five to nine times harder than metallic titanium, and this mismatch in hardness may lead to wear and damage to the titanium implant surface connected to the hard zirconia. Two reports from research projects have clearly demonstrated the potential for wear of titanium when mated with a zirconia abutment.2,3 This report describes two clinical cases in which dark tissue discoloration has occurred as a result of what appears to be embedded particulate titanium within the soft tissues adjacent to implants restored with zirconia abutments. 1Professor
and Head, Department of Reconstructive Sciences, University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA. 2Private Practice, Ho-Ho-Kus, New Jersey, USA. 3 Private Practice, Olympia, Washington, USA. Correspondence to: Dr Thomas D. Taylor, UConn School of Dental Medicine, 263 Farmington Ave, Farmington, Connecticut 06030-1615. Email: [email protected] ©2014 by Quintessence Publishing Co Inc.
CASE 1 A man aged 51 years presented to his dentist in April 2010 with a fractured maxillary left lateral incisor. The tooth root was extracted and a 3.7 mm–diameter titanium implant (Tapered Screw-Vent, Zimmer) was placed immediately. In August 2010 the implant was restored with a custom-milled zirconia abutment and lithium disilicate crown (IPS e.max, Ivoclar Vivadent) cemented with resin cement (RelyX Unicem, 3M ESPE). In January 2013 the patient noticed looseness of the restoration but deferred seeking care until May 2013. At that time the patient presented with the complaint of the loose tooth, and a radiograph was taken (Fig 1), which was unremarkable. There was no pain or suppuration noted; however, an area of pigmentation was noted in the mucosa overlying the implant/abutment connection (Fig 2). The patient noted that the pigmentation had developed “sometime after the implant was placed.” An access hole was made through the crown and the abutment screw and abutment were removed. It was noted that the base of the abutment that engaged the internal hex of the implant had fractured (Fig 3). The broken pieces were retrieved from inside the implant, and the abutment/crown assembly was screwed back on the implant to serve as a provisional restoration until a replacement could be fabricated. The crown was adjusted to avoid occlusal contact. The patient had a history of malignant melanoma, and therefore, a biopsy of the dark tissue was advised. The biopsy was performed in September 2013 and was negative for melanoma; however, there appeared to be fine, particulate material dispersed within the tissue that was assumed to be titanium (Fig 4). Clinically, the oral surgeon who performed the biopsy noted what appeared to be granular metallic particles in the tissue.
958 Volume 29, Number 4, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Taylor et al
Fig 1 Zirconia/porcelain restoration in a maxillary left lateral incisor implant. Image was taken after the restoration had been mobile for 5 months.
Fig 2 An area of dark discoloration is evident at the level of the implant-abutment connection.
Fig 3 The retrieved zirconia abutment/ crown had fractured at the internal hex connection.
Fig 4 This histologic specimen taken at biopsy revealed what appears to be finely granular material interspersed interstitially throughout the connective tissue.
CASE 2 The patient was a man aged 67 years who presented in December 2011 with the crown on the maxillary right central incisor slightly dislodged from its original position. It was determined that the metal post had slightly bent under occlusal load. Review of the treatment notes from the treating dentist showed that there was minimal tooth structure remaining when the crown was fabricated in 2006. The patient had been offered an implant restoration at that time, but he elected the post and core and crown. Considering the success of the implant restoration for the maxillary left central incisor, the patient elected the same treatment plan to replace the right incisor (Fig 5). In January 2012, the tooth was extracted and the socket prepared for an implant. An implant design with a sloped shoulder of the implant was utilized (OsseoSpeed TX Profile, Astra Tech Implants/Dentsply). The facial rim of the implant is 1.5 mm shorter than the lingual rim, which allows the implant to be placed shallower in the bone, while still maintaining the facial rim at the bone crest. The patient had a high osseous scallop, so use of this implant system allowed a 5.0 × 13–mm implant to be placed. The implant insertion torque was 50 Ncm. Xenograft (Bio-Oss, Geistlich) was placed in the facial gap, and a screw-retained provisional crown was fabricated chairside. The facial soft tissue was judged to be thick enough to not need an
additional connective tissue graft. The occlusion was assessed to ensure no centric or excursive contacts were present. Healing progressed uneventfully until 3 months postoperative. The provisional crown became loose, and a small fistulous tract appeared in the facial tissue at about the level of the implant-abutment interface (Fig 6). The crown was removed and disinfected. The internal aspect of the implant was cleaned, and the crown was reseated. The fistula resolved, and a final impression for the definitive crown was made in June 2012 utilizing a custom impression coping. A custom zirconia abutment designed for direct application of porcelain was utilized (Atlantis Crown Abutment, Dentsply). The porcelain-fused-to-zirconia screw-retained crown was seated in July 2012. The access hole was sealed with a cotton pellet and composite resin. In January 2013, the patient returned because the crown was loose. The access filling was removed and the crown removed. Upon removal, it was noted that the hex at the base of the abutment had fractured off, and the remnants of the hex were found on the threads of the abutment screw. The internal aspect of the implant was cleaned and the original provisional crown was seated and the patient dismissed. It was decided to fabricate a new crown using a metal abutment. A custom gold-shaded titanium abutment was fabricated using the same digital file stored at Atlantis that was used for the zirconia abutment. A porcelain-fused-to-metal crown was fabricated with a The International Journal of Oral & Maxillofacial Implants 959
© 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Taylor et al
Fig 5 Immediate post operative radiograph of immediately placed and provisionally restored maxillary right central incisor.
Fig 6 Fistula associated with loose provisional abut- Fig 7 The area surrounding the previous fistula ment approximately 3 months after implant placement. had become darkly discolored at the time of reThe provisional abutment was removed, cleaned, re- placement crown delivery. placed, and tightened. The fistula resolved shortly thereafter.
Fig 8 Two months following the placement of the second crown, the fistula had resolved but the tissue remained darkly pigmented.
hole to access the abutment screw. In March 2013, the replacement crown was placed. It was at the seating appointment of this second crown that a dark-pigmented area was noted at the mucogingival junction in the area of the old fistula from the provisional (Fig 7). There was some redness in the center of the pigmentation that appeared to be related to this fistula. This area of pigmentation was not noted before, and review of earlier photos showed no pigmentation previously. The patient returned in 2 months for a followup appointment. The fistula had resolved, but the area of pigmentation remained (Fig 8). Fortunately, the patient has a low smile line so this area does not show when he smiles or laughs. The relationship, if any, between the presence of a fistula and the subsequent appearance of the dark staining is not understood.
CONCLUSION Two cases of tissue discoloration associated with the use of zirconia abutments have been described. While the discoloration was not associated with esthetic compromise in these patients due to low gingival
display, the potential for such tissue discoloration to occur in esthetically critical sites should not be ignored. Improvements in design that preclude contact between the titanium implant and the zirconia abutment should be considered to avoid this type of complication.
ACKNOWLEDGMENTS The authors reported no conflicts of interest related to this study.
REFERENCES 1. Denry I, Kelly JR. State of the art of zirconia for biomedical applications. Dent Mater 2008;24:299–307. 2. Klotz M, Taylor T, Goldberg J. Wear at the titanium-zirconia implantabutment interface: A pilot study. Int J Oral Maxillofac Implants 2011;26:970–975. 3. Stimmelmayr M, Edelhoff D, Güth JF, Erdelt K, Happe A, Beuer F. Wear at the titanium-titanium and titanium-zirconia implantabutment interface: A comparative in vitro study. Dent Mater 2012;12:1215–1220.
960 Volume 29, Number 4, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
T
he use of zirconium oxide (zirconia) as a restorative material in dentistry has become widespread. Zirconia as an implant abutment material in place of titanium or other metals is primarily indicated in situations where the overlying soft tissue is thin and/or transparent and a metal abutment would cause discoloration of the tissue leading to an esthetic compromise. The use of the zirconia abutment has become commonplace in spite of its narrowly described indication for use in highly visible areas in patients with thin tissue phenotype. Concern has been expressed in the literature regarding the safety and efficacy of mating zirconia restorative abutments with titanium implants.1 Zirconia is five to nine times harder than metallic titanium, and this mismatch in hardness may lead to wear and damage to the titanium implant surface connected to the hard zirconia. Two reports from research projects have clearly demonstrated the potential for wear of titanium when mated with a zirconia abutment.2,3 This report describes two clinical cases in which dark tissue discoloration has occurred as a result of what appears to be embedded particulate titanium within the soft tissues adjacent to implants restored with zirconia abutments. 1Professor
and Head, Department of Reconstructive Sciences, University of Connecticut School of Dental Medicine, Farmington, Connecticut, USA. 2Private Practice, Ho-Ho-Kus, New Jersey, USA. 3 Private Practice, Olympia, Washington, USA. Correspondence to: Dr Thomas D. Taylor, UConn School of Dental Medicine, 263 Farmington Ave, Farmington, Connecticut 06030-1615. Email: [email protected] ©2014 by Quintessence Publishing Co Inc.
CASE 1 A man aged 51 years presented to his dentist in April 2010 with a fractured maxillary left lateral incisor. The tooth root was extracted and a 3.7 mm–diameter titanium implant (Tapered Screw-Vent, Zimmer) was placed immediately. In August 2010 the implant was restored with a custom-milled zirconia abutment and lithium disilicate crown (IPS e.max, Ivoclar Vivadent) cemented with resin cement (RelyX Unicem, 3M ESPE). In January 2013 the patient noticed looseness of the restoration but deferred seeking care until May 2013. At that time the patient presented with the complaint of the loose tooth, and a radiograph was taken (Fig 1), which was unremarkable. There was no pain or suppuration noted; however, an area of pigmentation was noted in the mucosa overlying the implant/abutment connection (Fig 2). The patient noted that the pigmentation had developed “sometime after the implant was placed.” An access hole was made through the crown and the abutment screw and abutment were removed. It was noted that the base of the abutment that engaged the internal hex of the implant had fractured (Fig 3). The broken pieces were retrieved from inside the implant, and the abutment/crown assembly was screwed back on the implant to serve as a provisional restoration until a replacement could be fabricated. The crown was adjusted to avoid occlusal contact. The patient had a history of malignant melanoma, and therefore, a biopsy of the dark tissue was advised. The biopsy was performed in September 2013 and was negative for melanoma; however, there appeared to be fine, particulate material dispersed within the tissue that was assumed to be titanium (Fig 4). Clinically, the oral surgeon who performed the biopsy noted what appeared to be granular metallic particles in the tissue.
958 Volume 29, Number 4, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Taylor et al
Fig 1 Zirconia/porcelain restoration in a maxillary left lateral incisor implant. Image was taken after the restoration had been mobile for 5 months.
Fig 2 An area of dark discoloration is evident at the level of the implant-abutment connection.
Fig 3 The retrieved zirconia abutment/ crown had fractured at the internal hex connection.
Fig 4 This histologic specimen taken at biopsy revealed what appears to be finely granular material interspersed interstitially throughout the connective tissue.
CASE 2 The patient was a man aged 67 years who presented in December 2011 with the crown on the maxillary right central incisor slightly dislodged from its original position. It was determined that the metal post had slightly bent under occlusal load. Review of the treatment notes from the treating dentist showed that there was minimal tooth structure remaining when the crown was fabricated in 2006. The patient had been offered an implant restoration at that time, but he elected the post and core and crown. Considering the success of the implant restoration for the maxillary left central incisor, the patient elected the same treatment plan to replace the right incisor (Fig 5). In January 2012, the tooth was extracted and the socket prepared for an implant. An implant design with a sloped shoulder of the implant was utilized (OsseoSpeed TX Profile, Astra Tech Implants/Dentsply). The facial rim of the implant is 1.5 mm shorter than the lingual rim, which allows the implant to be placed shallower in the bone, while still maintaining the facial rim at the bone crest. The patient had a high osseous scallop, so use of this implant system allowed a 5.0 × 13–mm implant to be placed. The implant insertion torque was 50 Ncm. Xenograft (Bio-Oss, Geistlich) was placed in the facial gap, and a screw-retained provisional crown was fabricated chairside. The facial soft tissue was judged to be thick enough to not need an
additional connective tissue graft. The occlusion was assessed to ensure no centric or excursive contacts were present. Healing progressed uneventfully until 3 months postoperative. The provisional crown became loose, and a small fistulous tract appeared in the facial tissue at about the level of the implant-abutment interface (Fig 6). The crown was removed and disinfected. The internal aspect of the implant was cleaned, and the crown was reseated. The fistula resolved, and a final impression for the definitive crown was made in June 2012 utilizing a custom impression coping. A custom zirconia abutment designed for direct application of porcelain was utilized (Atlantis Crown Abutment, Dentsply). The porcelain-fused-to-zirconia screw-retained crown was seated in July 2012. The access hole was sealed with a cotton pellet and composite resin. In January 2013, the patient returned because the crown was loose. The access filling was removed and the crown removed. Upon removal, it was noted that the hex at the base of the abutment had fractured off, and the remnants of the hex were found on the threads of the abutment screw. The internal aspect of the implant was cleaned and the original provisional crown was seated and the patient dismissed. It was decided to fabricate a new crown using a metal abutment. A custom gold-shaded titanium abutment was fabricated using the same digital file stored at Atlantis that was used for the zirconia abutment. A porcelain-fused-to-metal crown was fabricated with a The International Journal of Oral & Maxillofacial Implants 959
© 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
Taylor et al
Fig 5 Immediate post operative radiograph of immediately placed and provisionally restored maxillary right central incisor.
Fig 6 Fistula associated with loose provisional abut- Fig 7 The area surrounding the previous fistula ment approximately 3 months after implant placement. had become darkly discolored at the time of reThe provisional abutment was removed, cleaned, re- placement crown delivery. placed, and tightened. The fistula resolved shortly thereafter.
Fig 8 Two months following the placement of the second crown, the fistula had resolved but the tissue remained darkly pigmented.
hole to access the abutment screw. In March 2013, the replacement crown was placed. It was at the seating appointment of this second crown that a dark-pigmented area was noted at the mucogingival junction in the area of the old fistula from the provisional (Fig 7). There was some redness in the center of the pigmentation that appeared to be related to this fistula. This area of pigmentation was not noted before, and review of earlier photos showed no pigmentation previously. The patient returned in 2 months for a followup appointment. The fistula had resolved, but the area of pigmentation remained (Fig 8). Fortunately, the patient has a low smile line so this area does not show when he smiles or laughs. The relationship, if any, between the presence of a fistula and the subsequent appearance of the dark staining is not understood.
CONCLUSION Two cases of tissue discoloration associated with the use of zirconia abutments have been described. While the discoloration was not associated with esthetic compromise in these patients due to low gingival
display, the potential for such tissue discoloration to occur in esthetically critical sites should not be ignored. Improvements in design that preclude contact between the titanium implant and the zirconia abutment should be considered to avoid this type of complication.
ACKNOWLEDGMENTS The authors reported no conflicts of interest related to this study.
REFERENCES 1. Denry I, Kelly JR. State of the art of zirconia for biomedical applications. Dent Mater 2008;24:299–307. 2. Klotz M, Taylor T, Goldberg J. Wear at the titanium-zirconia implantabutment interface: A pilot study. Int J Oral Maxillofac Implants 2011;26:970–975. 3. Stimmelmayr M, Edelhoff D, Güth JF, Erdelt K, Happe A, Beuer F. Wear at the titanium-titanium and titanium-zirconia implantabutment interface: A comparative in vitro study. Dent Mater 2012;12:1215–1220.
960 Volume 29, Number 4, 2014 © 2014 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.
