ABSTRACT This case report describes the management of a loose cement-retained implant supported sectional bridge prothesis where the thread of the abutment screw had fractured away from the body of the screw

Muthu Mani

Pradeep Christopher

R Balakrishnan

Vijay Ebenezer

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ISSN: 0975-8585 
 
March–April  2015  RJPBCS 6(2)  Page No. 659 
Research Journal of Pharmaceutical, Biological and Chemical 
Sciences 
 
 
 
Fracture Body of Implant - Case Report. 
 
 
Vijay Ebenezer1*, R.Balakrishnan1, Pradeep Christopher2, Muthu Mani1 
 
1
Department of Oral and Maxillofacial Surgery, Sree Balaji Dental College & Hospital, Bharath University, Pallikaranai, 
Chennai, 600100, Tamil Nadu, India.
 
2
Department of Oral and Maxillofacial Surgery, Thaimoogambigai dental college & Hospital,Mogappair(west) Anna 
Nagar,Chennai, 600017, Tamil Nadu, India.
 
 
ABSTRACT 
 
This case report describes the management of a loose cement-retained implant supported  sectional 
bridge prothesis where the thread of the abutment screw had fractured away from the body of the screw. 
Keywords: dental implant,screw loosening, osseointigration. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
*Corresponding author 
 
ISSN: 0975-8585 
 
March–April  2015  RJPBCS 6(2)  Page No. 660 
INTRODUCTION 
 
Implants have become increasingly popular in the dental profession due to their predictability for the 
replacement of missing dentition [1]. Complications and failures do occur with dental implants [2]. 
Complications may arise at the time of implant placement or at the time of prosthesis fabrication. Fracture of 
screw takes place when excessive mechanical force on mastication, thus preventing damage to the bone 
implant interface [3,4]. Fracture may be of crown, framework, and screw fracture.  
 
A less common cause is fracture of the body of the implant; a study shows a 0.6% of failures [5]. 
Screw loosening is more often associated with single-unit restorations. . Screw loosening occurs when 
compressive occlusal forces are higher than the tension in the screw-implant assembly that holds the 
components together [6]. Complications from screw loosening can result in screw fracture, failure of implant 
or dislodgement of the prosthesis.
 
 
CASE REPORT 
 
A 46years old patient complains of disloged bridge in relation to implants on his upper teeth. History 
releaved that 3 years back he underwent implant supported sectional brigde treatment. On intraoral 
examination revealed an implant at 13 retaining the fractured segment of abutment screw within and below 
the head of the implant (fig 1). The other half of the fractured screw along with the abutment and fractured 
implant was in the dislodged crown.Fracture was in the body of the implant which resulted in failure of 
implant. The loose bridge was removed under local ansthesia together with implant fragment. The removal of 
the remaining implant fragment using bone trephine was done, followed by adequate quantity of bone graft 
for second fixture. An immediate temporary removable partial denture was given for replacement. Later after 
6 months patient was reviewed, full thickness flap raised for placement of implant. Implant of length 13mm 
and dimeter 3.75 mmwas placed over the site and healing was complete. After 2months abutment was placed, 
impression was made followed by ceramic- metal bridge prosthesis . 
 
 
 
Figure 1: Fractured Prosthesis with Body of Implant 
 
DISCUSSION 
 
Implant body fracture is a rare complication of implant treatment occurring only in 0.6% of implant 
cases [5]. Damage of the internal implant thread can lead to failure of implant due to failure to restore. 
Occlusal overload is also a cause. Bridge with cantilever design will further increase bending forces on implants 
and and the supporting bone leading to bone loss.  
 
Rangert et al. [7] found that partial bridges with cantilever designs accounted for 83% of implant 
fractures and that 90% of fractures occurred in the posterior regions. It has been shown in animal studies that 
crater-like bone loss will occur around implants with excessive dynamic loading [8]
 
and this loss of bone 
support will allow flexing of an implant under loading and possibly contribute to a fatigue stress 
ISSN: 0975-8585 
 
March–April  2015  RJPBCS 6(2)  Page No. 661 
fracture. Planning the treatment and proper occlusal adjustment usually ensure that the implant crown is not 
overloaded by occlusal forces.  
 
Tightening the abutment screw to the correct torque will minimize the incidence of screw. Before 
prosthetic screw loosening leading to screw fracture use to occur when occlusal overloading is done, but in 
recent days improved screw design can overcome the problem by allowing higher preloads. This may however 
has led to failure elsewhere in the system as fracture of the body of the implant. Fracture of the body of an 
implant is a major cause of late failure
5
 which may be avoidable with careful planning.  
 
CONCLUSION 
 
Adequate planning of treatment, good occlusal adjustment, and tightening screw to the correct 
torque will minimize the incidence of loosening and fracture of abutment screws and leading to fracture of the 
implant body. 
 
REFERENCES 
 
[1] Morris HF, et al. J Oral Implantol 2003;30; 3:125-33.   
[2] Goodacre CJ, Kan JY, Rungcharassaeng K. J Prosthet Dent 1999;81:537-52.. 
[3] Kreissl ME, Gerds T, Muche R, Heydecke G, Strub JR. Clin Oral Implants Res 2007;18:720-6. 
[4] Jung RE, Pjetursson BE, Glauser R, Zembic A, Zwahlen M, Lang NP. Clin Oral Implants Res 2008;19:119-
30. 
[5] Eckert S E, Meraw S J, Cal E, Ow R K. Int J Oral Maxillofac Implants 2000; 15: 662-667. 
[6] Binon PP, McHugh MJ. Int J Prosthod 1996;9:511-9. 
[7] Duyck J, Ronold HJ, Van Oosterwyck H, Naert I, Vander Sloten J, Ellingsen JE.  Clin Oral Implants Res 
2001; 12: 207–218. 
[8] Kallus T, Bessing C.  Int J Oral Maxillofac Implants1994; 9: 169–178. 


Fracture Body of Implant -Case Report

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