Australian Dental Journal
The official journal of the Australian Dental Association
Australian Dental Journal 2014; 59: 149–155 doi: 10.1111/adj.12170
A study of osseointegrated dental implants following cremation JW Berketa,* H James,* NEI Langlois,† LC Richards‡ *Forensic Odontology Unit, The University of Adelaide, South Australia. †Forensic Science Centre of South Australia. ‡School of Dentistry, The University of Adelaide, South Australia.
ABSTRACT Background: The comparison of dental morphology and restorative work for human identification has been well documented. This case study involved documentation of osseointegrated and clinically restored dental implants following cremation. Methods: The mandible and the maxilla were excised from a head containing implants and cremated. The remains were retrieved, digital and radiographic images were taken and elemental analysis undertaken. The brand of implants was identified utilizing web based search engines. A prosthodontist, known to commonly use this implant system, was approached to ascertain possibilities that matched the data given. Results: Following cremation the implants were identified and a prosthodontist was able to identify the deceased. Two implants in the maxilla had dehiscences on their buccal surfaces, which could not be detected by periapical radiographs. Conclusions: Dental implants osseointegrated and restored with a prosthetic superstructure were recognizable following severe incineration. It was possible to trace back the identity of the unknown victim to a prosthodontist. Bone dehiscences discovered in this study highlighted how two-dimensional radiographs may not reveal lack of bone support. Keywords: Forensic identification, implants, cremation, dehiscence. Abbreviations and acronyms: SEM = scanning electron microscope. (Accepted for publication 12 July 2013.)
INTRODUCTION The incidence of disasters involving incineration of victims is increasing due to higher global temperatures creating a fire-prone environment,1–3 increasing acts of terrorism4 and increased high-speed travel.5 The identification of victims of incineration events is a daunting and intensive task.6 Depending on the severity and duration fire will damage or destroy physical evidence such as clothing, documents, tattoos, fingerprints, and hair,7 and at high temperatures the DNA could be denatured.8 The dental structures are the most resilient structures of the body9 and together with some dental materials they are able to resist high temperatures and retain their physical shape, producing an excellent source of distinction among individuals.10–13 However, the loss of the organic component of human teeth causes shrinkage and cracking14,15 and above 1000 °C the teeth became very fragile. Other problems in the preservation of remains include damage © 2014 Australian Dental Association
by falling rubble, accidental damage by firefighters and exposure to the damaging effects of weather and animal predation.2,16 Implants as a treatment option are occurring at a rapidly growing rate,17,18 increasing the likelihood that they will be present in deceased victims and detected in post-mortem radiographic examination. As commercially pure titanium and titanium alloy dental implants have a melting point greater than 1650 °C,19 the likelihood of implants surviving severe thermal insult is high. If the deceased is unknown the detection of dental implants could aid in the investigation of the victim by identifying the type, make and sizes of the implants.20 There are over 463 different implant types around the world.21 Questioning the implant manufacturer’s sales representatives from that area with regard to sales of the particular type and size of the implants recovered in the post-mortem examination could narrow the possibilities from a list of missing persons. The results of recent research suggest that 149
JW Berketa et al. dental implants are still recognizable following incineration22 but there are currently no published articles in relation to the identification of incinerated implants which have been osseointegrated within human tissue. The objectives of this study were to investigate if dental implants which have been osseointegrated and restored with a prosthetic superstructure were recognizable following severe incineration; if it was possible to trace the identity of an unknown victim using data from implants to locate the treating dentist; and if serial numbers within the chamber of a restored implant were retrievable after incineration. MATERIALS AND METHODS University of Adelaide human ethics approval was sought and approved (H-2012-111). Forty cadavers from the University of Adelaide body donation programme were examined for dental implants and intraoral radiographs taken to assess osseointegration and peri-implant pathology. Following the granting of a Cremation Permit, a maxilla (immediately below the lower border of the orbit) and mandible were excised, placed in a sealed plastic bag and cremated in a normal human cremation cycle (maximum temperature of 1050 °C). Retrieval from the crematorium was delayed until the following morning to allow for cooling. The material was carefully removed and the findings documented. Web based search engines (www.whichimplant.com, www.whatimplantisthat.com, www.osseosource.com) together with the lead author’s knowledge were used to determine the type of implants. The implants, together with the superstructures upon them, were investigated to visually examine the surfaces. Elemental analysis with the aid of a scanning electron microscope (QUANTA 450, FEI Co., Hillsboro, Oregon, USA) was also performed with the objective of gaining maximum data to allow eventual identification of the individual. Once the type of implant was ascertained, it was planned to approach local sales representatives to ascertain which local operators utilized that specific implant system and to contact these operators to find out if any of their patients matched the data recovered.
supported by these implants was still in position and without obvious distortion. The grey colouring (as shown in Fig. 1 and Fig. 2), and lack of distortion suggested that it was of titanium origin. The maxilla had five implants. Two implants had dislodged from the bone and had a large mass of melted alloy attached to them (Fig. 3). Burring with a high speed diamond bur indicated a gold colour alloy had been used to support the maxilla superstructure. Two implants in the maxilla had dehiscences on their buccal surfaces (Fig. 4 and Fig. 5). However, periapical radiographs of these implants do not hint at the lack of buccal support (Fig. 6 and Fig. 7). As the implants were straight sided, non-threaded, holed at the apex and matched the images on the websites, they were identified as Calcitek® implants. No prosthetic teeth structures survived the incineration process, suggesting acrylic teeth were originally on the superstructure. Scanning electron microscope (SEM) analysis of the upper alloy confirmed that it was an alloy containing gold, as shown in Fig. 8, and that the lower alloy was made of titanium (Fig. 9). The implant surfaces were covered by a calciumphosphorous layer, as shown in Fig. 10, which also corresponds to hydroxyapetite coated Calcitek® implants. The abutments contained mainly gold and zinc elements (Fig. 11 and Fig. 12). Examination revealed only one retention screw still present. The upper superstructure had melted onto two implants and the lower superstructure proved impossible to remove from the implants. Calcitek® implants do not have numbers within them, but had they had numbers they would have been extremely difficult to identify as thick oxidation was covering all the metal surfaces. The need to approach the sales representative of the company to ascertain which surgeons place this type of implants was not required as the author knew of local dental operators who had utilized this type of implants. A local prosthodontist who has constructed
RESULTS Following examination of the cadavers, only one cadaver with nine implants within the oral structures was suitable as all other heads either did not contain dental implants nor had dental implants removed during earlier anatomy classes. Following cremation, the mandible had still retained its four implants although one of the implants had been sectioned in half during the anatomy instruction. The metal superstructure 150
Fig. 1 Lower right mandible. © 2014 Australian Dental Association
Dental implants following cremation
Fig. 2 Lower left mandible.
Fig. 5 Upper right maxilla segment.
Fig. 3 Loose maxillary implants with alloy attached. Fig. 6 Radiograph of upper left segment.
Fig. 4 Upper left maxilla segment. Fig. 7 Radiograph of upper right segment.
many prostheses supported by Calcitek® implants was approached and the data sourced from the documentation and images were presented to him. Utilizing his computer records of his implant patients, he searched © 2014 Australian Dental Association
for possibilities that matched the records revealed that there were 10 a gold alloy hybrid upper dentition Calcitek® implants. With regard to
data given. His patients who had supported by five the lowers, there 151
JW Berketa et al. Lable A: gold alloy
Au
C Zn O Zn
Au
Pd Pd Au Pd
Pd
Cu
2.00
4.00
6.00
8.00
Cu 10.00
Fig. 8 Elemental analysis of upper superstructure.
Lable A: tianium framework 1 spot Ti
C O Ti
Na Ti
AI
Ti K
Zr Zr
2.00
Zr
K 4.00
6.00
8.00
10.00
Fig. 9 Elemental analysis of lower superstructure.
were 26 patients that had a titanium superstructure supported by four Calcitek® implants. Cross-checking the lists, there was only one patient on both lists and the name corresponded to the name on the Cremation Permit. DISCUSSION The implants were identified correctly, however there are some implant companies that are very similar and imitate other successful companies’ implants. These clones could lead to misidentification of the implant and the wrong leads could be followed. Companies tend to construct implants only of certain lengths and widths, and it is important to verify the sizes with the 152
website engines mentioned previously. Contacting the companies directly or scanning their information pamphlets to ascertain the measuring points is also critical. As well as the types of implants and their sizes, the differential diagnosis extends to the type of superstructure (gold alloy, titanium, chrome, zirconia or combinations of other elements), the abutment type (gold, titanium, zirconia and whether cast or preformed) and importantly if crown structure is found what type of material is it constructed from (various porcelains, zirconia, porcelain bonded to metal or gold) and whether the crowns were screw retained or cemented. Finally, the implant surface could be examined under SEM for its texture and elemental analysis. © 2014 Australian Dental Association
Dental implants following cremation P O Na
Ca
K C
Mg
Ca K 2.00
4.00
6.00
8.00
10.00
Fig. 10 Elemental analysis of implant surface.
Lable A: gold alloy Au
Pd
C Au
Pd Au
Pd Au
Pd 2.00
4.00
6.00
8.00
Au 10.00
Fig. 11 Elemental analysis of abutment indicating gold present.
The difficulty in even trying to separate the abutment from the implant questions whether a number if etched within the implant chamber would be recovered. The increase in oxidation caused by the high temperature created a welding effect. Any flow of superstructure material over the access hole would compound the difficulty. Even though some implants were lost or the main bone structure had separated, there was still visual evidence of dehydrated bone remaining on the implant surfaces. Different types of implants would need to be investigated to see if this holds true for most implants. It was fortunate that upon visiting the first operator, a successful identification was reached. There © 2014 Australian Dental Association
could also be more than one match for any configuration, especially on singular implants. Other operators could also have a match and sourced to rule out other possibilities. Caution should be maintained. Good record keeping is essential and if records are not as well documented or maintained this method will not be successful. The dehiscences discovered raise some interesting points. Were they deliberately placed as such or did this occur over time? The implants were not placed by the operator so no information was obtained regarding the insertion technique. As there was no indication on the radiographs, the two-dimensional view could lull operators into thinking that they had extremely good bone osseointegration. In this case the 153
JW Berketa et al. Label A: gold alloy Zn
O
C
Zn Zn Zn 2.00
4.00
6.00
8.00
10.00
Fig. 12 Elemental analysis of abutment indicating zinc present.
implants had been in place for over 13 years and stable. Rather than examining only radiographs, the investigation of implants post-mortem allows further scrutiny and understanding of the interrelationship of bone to implants. ACKNOWLEDGEMENTS The authors gratefully acknowledge the Ray Last Laboratory and the Enfield Memorial Park Crematorium for the generous use of their facilities; the Australian Dental Research Foundation for the grant supporting this project; and Adelaide Microscopy for the use of their SEM. REFERENCES 1. Pechony O, Shindell DT. Driving forces of global wildfires over the past millennium and the forthcoming century. Proc Natl Acad Sci U S A 2010;107:19167–19170. 2. Byard RW, Gilbert JD, Kostakis C, Heath KJ. Circumstances of death and diagnostic difficulties in brushfire fatalities. J Forensic Sci 2012;57:969–972. 3. Johnston FH. Bushfires and human health in a changing environment. Aust Fam Physician 2009;38:720–724. 4. Bonavilla JD, Bush MA, Bush PJ, Pantera EA. Identification of incinerated root canal filling materials after exposure to high heat incineration. J Forensic Sci 2008;53:412–418. 5. Muthusubramanian M, Limson KS, Julian R. Analysis of rugae in burn victims and cadavers to simulate rugae identification in cases of incineration and decomposition. J Forensic Odontostomatol 2005;23:26–29. 6. Bush MA, Bush PJ, Miller RG. Detection and classification of composite resins in incinerated teeth for forensic purposes. J Forensic Sci 2006;51:636–642. 7. Holden JL, Clement JG, Phakey PP. Age and temperature related changes to the ultrastructure and composition of human bone mineral. J Bone Miner Res 1995;10:1400–1409. 154
8. von Wurmb-Schwark N, Simeoni E, Ringleb A, Oehmichen M. Genetic investigation of modern burned corpses. Int Congr 2004;1261:50–52. 9. Woisetschl€ager M, Lussi A, Persson A, Jackowski C. Fire victim identification by post-mortem dental CT: radiologic evaluation of restorative materials after exposure to high temperatures. Eur J Radiol 2011;80:432–440. 10. Marella GL, Rossi P. An approach to person identification by means of dental prostheses in a burnt corpse. J Forensic Odontostomatol 1999;17:16–19. 11. Rossouw RJ, Grobler SR, Phillips VM, van WKTJ. The effects of extreme temperatures on composite, compomer and ionomer restorations. J Forensic Odontostomatol 1999;17:1–4. 12. Hill AJ, Lain R, Hewson I. Preservation of dental evidence following exposure to high temperatures. Forensic Sci Int 2011;205:40–43. 13. Bush MA, Miller RG, Prutsman-Pfeiffer J, Bush PJ. Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals. J Forensic Sci 2007;52:157–165. 14. Thompson TJ. Recent advances in the study of burned bone and their implications for forensic anthropology. Forensic Sci Int 2004;146(Suppl):S203–205. 15. Reichs KJ. Forensic osteology: advances in the identification of human remains. 2nd edn. Springfield: Charles C. Thomas, 1998. 16. Asamura H, Takayanagi K, Ota M, Kobayashi K, Fukushima H. Unusual characteristic patterns of postmortem injuries. J Forensic Sci 2004;49:592–594. 17. Laine P, Salo A, Kontio R, Ylijoki S, Lindqvist C, Suuronen R. Failed dental implants – clinical, radiological and bacteriological findings in 17 patients. J Craniomaxillofac Surg 2005;33: 212–217. 18. Iqbal MK, Kim S. A review of factors influencing treatment planning decisions of single-tooth implants versus preserving natural teeth with nonsurgical endodontic therapy. J Endod 2008;34:519–529. 19. Ashby MF, Jones DRH. Engineering Materials. An Introduction to their Properties and Applications. Oxford: Pergamon, 1980. © 2014 Australian Dental Association
Dental implants following cremation 20. Berketa JW, Hirsch RS, Higgins D, James H. Radiographic recognition of dental implants as an aid to identifying the deceased. J Forensic Sci 2010;55:66–70. 21. Barclay CW. whichimplant.com. Available from: URL: ‘http:// www.whichimplant.com/’. 22. Berketa J, James H, Marino V. Survival of batch numbers within dental implants following incineration as an aid to identification. J Forensic Odontostomatol 2010;28:1–4.
© 2014 Australian Dental Association
Address for correspondence: Dr John Berketa Forensic Odontology Unit The University of Adelaide Adelaide SA 5005 Email: [email protected]
155
The official journal of the Australian Dental Association
Australian Dental Journal 2014; 59: 149–155 doi: 10.1111/adj.12170
A study of osseointegrated dental implants following cremation JW Berketa,* H James,* NEI Langlois,† LC Richards‡ *Forensic Odontology Unit, The University of Adelaide, South Australia. †Forensic Science Centre of South Australia. ‡School of Dentistry, The University of Adelaide, South Australia.
ABSTRACT Background: The comparison of dental morphology and restorative work for human identification has been well documented. This case study involved documentation of osseointegrated and clinically restored dental implants following cremation. Methods: The mandible and the maxilla were excised from a head containing implants and cremated. The remains were retrieved, digital and radiographic images were taken and elemental analysis undertaken. The brand of implants was identified utilizing web based search engines. A prosthodontist, known to commonly use this implant system, was approached to ascertain possibilities that matched the data given. Results: Following cremation the implants were identified and a prosthodontist was able to identify the deceased. Two implants in the maxilla had dehiscences on their buccal surfaces, which could not be detected by periapical radiographs. Conclusions: Dental implants osseointegrated and restored with a prosthetic superstructure were recognizable following severe incineration. It was possible to trace back the identity of the unknown victim to a prosthodontist. Bone dehiscences discovered in this study highlighted how two-dimensional radiographs may not reveal lack of bone support. Keywords: Forensic identification, implants, cremation, dehiscence. Abbreviations and acronyms: SEM = scanning electron microscope. (Accepted for publication 12 July 2013.)
INTRODUCTION The incidence of disasters involving incineration of victims is increasing due to higher global temperatures creating a fire-prone environment,1–3 increasing acts of terrorism4 and increased high-speed travel.5 The identification of victims of incineration events is a daunting and intensive task.6 Depending on the severity and duration fire will damage or destroy physical evidence such as clothing, documents, tattoos, fingerprints, and hair,7 and at high temperatures the DNA could be denatured.8 The dental structures are the most resilient structures of the body9 and together with some dental materials they are able to resist high temperatures and retain their physical shape, producing an excellent source of distinction among individuals.10–13 However, the loss of the organic component of human teeth causes shrinkage and cracking14,15 and above 1000 °C the teeth became very fragile. Other problems in the preservation of remains include damage © 2014 Australian Dental Association
by falling rubble, accidental damage by firefighters and exposure to the damaging effects of weather and animal predation.2,16 Implants as a treatment option are occurring at a rapidly growing rate,17,18 increasing the likelihood that they will be present in deceased victims and detected in post-mortem radiographic examination. As commercially pure titanium and titanium alloy dental implants have a melting point greater than 1650 °C,19 the likelihood of implants surviving severe thermal insult is high. If the deceased is unknown the detection of dental implants could aid in the investigation of the victim by identifying the type, make and sizes of the implants.20 There are over 463 different implant types around the world.21 Questioning the implant manufacturer’s sales representatives from that area with regard to sales of the particular type and size of the implants recovered in the post-mortem examination could narrow the possibilities from a list of missing persons. The results of recent research suggest that 149
JW Berketa et al. dental implants are still recognizable following incineration22 but there are currently no published articles in relation to the identification of incinerated implants which have been osseointegrated within human tissue. The objectives of this study were to investigate if dental implants which have been osseointegrated and restored with a prosthetic superstructure were recognizable following severe incineration; if it was possible to trace the identity of an unknown victim using data from implants to locate the treating dentist; and if serial numbers within the chamber of a restored implant were retrievable after incineration. MATERIALS AND METHODS University of Adelaide human ethics approval was sought and approved (H-2012-111). Forty cadavers from the University of Adelaide body donation programme were examined for dental implants and intraoral radiographs taken to assess osseointegration and peri-implant pathology. Following the granting of a Cremation Permit, a maxilla (immediately below the lower border of the orbit) and mandible were excised, placed in a sealed plastic bag and cremated in a normal human cremation cycle (maximum temperature of 1050 °C). Retrieval from the crematorium was delayed until the following morning to allow for cooling. The material was carefully removed and the findings documented. Web based search engines (www.whichimplant.com, www.whatimplantisthat.com, www.osseosource.com) together with the lead author’s knowledge were used to determine the type of implants. The implants, together with the superstructures upon them, were investigated to visually examine the surfaces. Elemental analysis with the aid of a scanning electron microscope (QUANTA 450, FEI Co., Hillsboro, Oregon, USA) was also performed with the objective of gaining maximum data to allow eventual identification of the individual. Once the type of implant was ascertained, it was planned to approach local sales representatives to ascertain which local operators utilized that specific implant system and to contact these operators to find out if any of their patients matched the data recovered.
supported by these implants was still in position and without obvious distortion. The grey colouring (as shown in Fig. 1 and Fig. 2), and lack of distortion suggested that it was of titanium origin. The maxilla had five implants. Two implants had dislodged from the bone and had a large mass of melted alloy attached to them (Fig. 3). Burring with a high speed diamond bur indicated a gold colour alloy had been used to support the maxilla superstructure. Two implants in the maxilla had dehiscences on their buccal surfaces (Fig. 4 and Fig. 5). However, periapical radiographs of these implants do not hint at the lack of buccal support (Fig. 6 and Fig. 7). As the implants were straight sided, non-threaded, holed at the apex and matched the images on the websites, they were identified as Calcitek® implants. No prosthetic teeth structures survived the incineration process, suggesting acrylic teeth were originally on the superstructure. Scanning electron microscope (SEM) analysis of the upper alloy confirmed that it was an alloy containing gold, as shown in Fig. 8, and that the lower alloy was made of titanium (Fig. 9). The implant surfaces were covered by a calciumphosphorous layer, as shown in Fig. 10, which also corresponds to hydroxyapetite coated Calcitek® implants. The abutments contained mainly gold and zinc elements (Fig. 11 and Fig. 12). Examination revealed only one retention screw still present. The upper superstructure had melted onto two implants and the lower superstructure proved impossible to remove from the implants. Calcitek® implants do not have numbers within them, but had they had numbers they would have been extremely difficult to identify as thick oxidation was covering all the metal surfaces. The need to approach the sales representative of the company to ascertain which surgeons place this type of implants was not required as the author knew of local dental operators who had utilized this type of implants. A local prosthodontist who has constructed
RESULTS Following examination of the cadavers, only one cadaver with nine implants within the oral structures was suitable as all other heads either did not contain dental implants nor had dental implants removed during earlier anatomy classes. Following cremation, the mandible had still retained its four implants although one of the implants had been sectioned in half during the anatomy instruction. The metal superstructure 150
Fig. 1 Lower right mandible. © 2014 Australian Dental Association
Dental implants following cremation
Fig. 2 Lower left mandible.
Fig. 5 Upper right maxilla segment.
Fig. 3 Loose maxillary implants with alloy attached. Fig. 6 Radiograph of upper left segment.
Fig. 4 Upper left maxilla segment. Fig. 7 Radiograph of upper right segment.
many prostheses supported by Calcitek® implants was approached and the data sourced from the documentation and images were presented to him. Utilizing his computer records of his implant patients, he searched © 2014 Australian Dental Association
for possibilities that matched the records revealed that there were 10 a gold alloy hybrid upper dentition Calcitek® implants. With regard to
data given. His patients who had supported by five the lowers, there 151
JW Berketa et al. Lable A: gold alloy
Au
C Zn O Zn
Au
Pd Pd Au Pd
Pd
Cu
2.00
4.00
6.00
8.00
Cu 10.00
Fig. 8 Elemental analysis of upper superstructure.
Lable A: tianium framework 1 spot Ti
C O Ti
Na Ti
AI
Ti K
Zr Zr
2.00
Zr
K 4.00
6.00
8.00
10.00
Fig. 9 Elemental analysis of lower superstructure.
were 26 patients that had a titanium superstructure supported by four Calcitek® implants. Cross-checking the lists, there was only one patient on both lists and the name corresponded to the name on the Cremation Permit. DISCUSSION The implants were identified correctly, however there are some implant companies that are very similar and imitate other successful companies’ implants. These clones could lead to misidentification of the implant and the wrong leads could be followed. Companies tend to construct implants only of certain lengths and widths, and it is important to verify the sizes with the 152
website engines mentioned previously. Contacting the companies directly or scanning their information pamphlets to ascertain the measuring points is also critical. As well as the types of implants and their sizes, the differential diagnosis extends to the type of superstructure (gold alloy, titanium, chrome, zirconia or combinations of other elements), the abutment type (gold, titanium, zirconia and whether cast or preformed) and importantly if crown structure is found what type of material is it constructed from (various porcelains, zirconia, porcelain bonded to metal or gold) and whether the crowns were screw retained or cemented. Finally, the implant surface could be examined under SEM for its texture and elemental analysis. © 2014 Australian Dental Association
Dental implants following cremation P O Na
Ca
K C
Mg
Ca K 2.00
4.00
6.00
8.00
10.00
Fig. 10 Elemental analysis of implant surface.
Lable A: gold alloy Au
Pd
C Au
Pd Au
Pd Au
Pd 2.00
4.00
6.00
8.00
Au 10.00
Fig. 11 Elemental analysis of abutment indicating gold present.
The difficulty in even trying to separate the abutment from the implant questions whether a number if etched within the implant chamber would be recovered. The increase in oxidation caused by the high temperature created a welding effect. Any flow of superstructure material over the access hole would compound the difficulty. Even though some implants were lost or the main bone structure had separated, there was still visual evidence of dehydrated bone remaining on the implant surfaces. Different types of implants would need to be investigated to see if this holds true for most implants. It was fortunate that upon visiting the first operator, a successful identification was reached. There © 2014 Australian Dental Association
could also be more than one match for any configuration, especially on singular implants. Other operators could also have a match and sourced to rule out other possibilities. Caution should be maintained. Good record keeping is essential and if records are not as well documented or maintained this method will not be successful. The dehiscences discovered raise some interesting points. Were they deliberately placed as such or did this occur over time? The implants were not placed by the operator so no information was obtained regarding the insertion technique. As there was no indication on the radiographs, the two-dimensional view could lull operators into thinking that they had extremely good bone osseointegration. In this case the 153
JW Berketa et al. Label A: gold alloy Zn
O
C
Zn Zn Zn 2.00
4.00
6.00
8.00
10.00
Fig. 12 Elemental analysis of abutment indicating zinc present.
implants had been in place for over 13 years and stable. Rather than examining only radiographs, the investigation of implants post-mortem allows further scrutiny and understanding of the interrelationship of bone to implants. ACKNOWLEDGEMENTS The authors gratefully acknowledge the Ray Last Laboratory and the Enfield Memorial Park Crematorium for the generous use of their facilities; the Australian Dental Research Foundation for the grant supporting this project; and Adelaide Microscopy for the use of their SEM. REFERENCES 1. Pechony O, Shindell DT. Driving forces of global wildfires over the past millennium and the forthcoming century. Proc Natl Acad Sci U S A 2010;107:19167–19170. 2. Byard RW, Gilbert JD, Kostakis C, Heath KJ. Circumstances of death and diagnostic difficulties in brushfire fatalities. J Forensic Sci 2012;57:969–972. 3. Johnston FH. Bushfires and human health in a changing environment. Aust Fam Physician 2009;38:720–724. 4. Bonavilla JD, Bush MA, Bush PJ, Pantera EA. Identification of incinerated root canal filling materials after exposure to high heat incineration. J Forensic Sci 2008;53:412–418. 5. Muthusubramanian M, Limson KS, Julian R. Analysis of rugae in burn victims and cadavers to simulate rugae identification in cases of incineration and decomposition. J Forensic Odontostomatol 2005;23:26–29. 6. Bush MA, Bush PJ, Miller RG. Detection and classification of composite resins in incinerated teeth for forensic purposes. J Forensic Sci 2006;51:636–642. 7. Holden JL, Clement JG, Phakey PP. Age and temperature related changes to the ultrastructure and composition of human bone mineral. J Bone Miner Res 1995;10:1400–1409. 154
8. von Wurmb-Schwark N, Simeoni E, Ringleb A, Oehmichen M. Genetic investigation of modern burned corpses. Int Congr 2004;1261:50–52. 9. Woisetschl€ager M, Lussi A, Persson A, Jackowski C. Fire victim identification by post-mortem dental CT: radiologic evaluation of restorative materials after exposure to high temperatures. Eur J Radiol 2011;80:432–440. 10. Marella GL, Rossi P. An approach to person identification by means of dental prostheses in a burnt corpse. J Forensic Odontostomatol 1999;17:16–19. 11. Rossouw RJ, Grobler SR, Phillips VM, van WKTJ. The effects of extreme temperatures on composite, compomer and ionomer restorations. J Forensic Odontostomatol 1999;17:1–4. 12. Hill AJ, Lain R, Hewson I. Preservation of dental evidence following exposure to high temperatures. Forensic Sci Int 2011;205:40–43. 13. Bush MA, Miller RG, Prutsman-Pfeiffer J, Bush PJ. Identification through X-ray fluorescence analysis of dental restorative resin materials: a comprehensive study of noncremated, cremated, and processed-cremated individuals. J Forensic Sci 2007;52:157–165. 14. Thompson TJ. Recent advances in the study of burned bone and their implications for forensic anthropology. Forensic Sci Int 2004;146(Suppl):S203–205. 15. Reichs KJ. Forensic osteology: advances in the identification of human remains. 2nd edn. Springfield: Charles C. Thomas, 1998. 16. Asamura H, Takayanagi K, Ota M, Kobayashi K, Fukushima H. Unusual characteristic patterns of postmortem injuries. J Forensic Sci 2004;49:592–594. 17. Laine P, Salo A, Kontio R, Ylijoki S, Lindqvist C, Suuronen R. Failed dental implants – clinical, radiological and bacteriological findings in 17 patients. J Craniomaxillofac Surg 2005;33: 212–217. 18. Iqbal MK, Kim S. A review of factors influencing treatment planning decisions of single-tooth implants versus preserving natural teeth with nonsurgical endodontic therapy. J Endod 2008;34:519–529. 19. Ashby MF, Jones DRH. Engineering Materials. An Introduction to their Properties and Applications. Oxford: Pergamon, 1980. © 2014 Australian Dental Association
Dental implants following cremation 20. Berketa JW, Hirsch RS, Higgins D, James H. Radiographic recognition of dental implants as an aid to identifying the deceased. J Forensic Sci 2010;55:66–70. 21. Barclay CW. whichimplant.com. Available from: URL: ‘http:// www.whichimplant.com/’. 22. Berketa J, James H, Marino V. Survival of batch numbers within dental implants following incineration as an aid to identification. J Forensic Odontostomatol 2010;28:1–4.
© 2014 Australian Dental Association
Address for correspondence: Dr John Berketa Forensic Odontology Unit The University of Adelaide Adelaide SA 5005 Email: [email protected]
155
