Bacterial leakage of different internal implant/abutment connection

Evaluating the microgap and sealing capability in four implant systems with different interlockings under different tightening torques: an in-vitro study

PURPOSE

This study assessed the microgap width and adhesion of three bacterial species in four dental implants with different interlocks under four screwing torques.

MATERIALS AND METHODS

Ten samples of four implant systems with various interlockings, including full-hexagonal (FHI), cylindrical-conical trilobe-index (TLI), Morse-taper with octagon terminal index (OI), and hexagonal interlock (slip-fit) (HI-SF), were used. The abutments were screwed to the fixtures under torques of 10, 20, 30, and 40 Ncm. The microgap between the abutment and the platform was assessed using a Scanning Electron Microscope (SEM). The leakage of 3 bacteria, including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, was evaluated under 30 Ncm torque.

RESULTS

The TLI system showed the widest gap under all torques compared to others. There was no significance among all systems under different screwing torques. Regarding the leakage, there was no adherence to E. coli and S. aureus and 36.4% of Ps. aeruginosa to the HI-SF, followed by the OI system. The FHI and TLI systems showed the highest bacterial adherence.

CONCLUSION

Even with low torque, the studied systems showed gap widths narrower than acceptable width. Implant systems with FHI and OI demonstrated misfits of less than 2 µm upon 10 Ncm and less than 1 µm when the torque increases, giving them priority to be used in areas with poor bone quality. The HI-SF demonstrated a high ability to resist the adherence to E. coli and S. aureus, followed by OI. However, Ps. aeruginosa demonstrated a high ability to adhere to all systems.

Assessment of Microgap and Bacterial Leakage of Two Types of Internal Implant-Abutment Union

Objective

The current research was done to assess microbial seepage of two types of internal implant-abutment connections.

Materials and Methods

Twenty dental implants are categorized into two groups. Group A fixtures with an internal hexagonal geometry and group B fixtures with a tri-lobe internal connection. All implant-abutment assemblies underwent a three-week incubation period at 37°C in sterile tubes containing 5 mL of Staphylococcus aureus broth culture. Through the use of Gram stain and biochemical processes, the resultant colonies were recognized.

Results

The mean Log10 colony forming unit (CFU) in group A was 8.4 and in group B was 7.2. The variation between both groups was found to be considerable (P < 0.05). Microgap was more in group B compared to group A.

Conclusion

Bacteria may infiltrate the small area between the implant and the abutment. Compared to dental implant fixtures with a tri-lobe internal connection, there was a noticeably higher Log10 CFU in dental implant fixtures with an internal hexagonal geometry.

The impact of Morse taper implant design on microleakage at implant-healing abutment interface

The microbial leakage at the implant-abutment interface (IAI) is one cause of peri-implant infection that puts long-term implant stability at risk. The present study compared two types of Morse taper implants in terms of sealing performance at the implanthealing abutment interface. Three implant systems, one of which exhibited a partial face-contact design (TSO) and the other two a line-contact design (TSM and BLT), were analyzed in vitro using two quantitative implant leakage measuring techniques: air-injection pressure measurement test and microbial examination. An in-house-developed device was used to determine implant leakage by recording the initial drop in pressure while injecting air through the implant. The microbial examination measured the absorbances of culture mediums in which the inoculated implants were contained. Significant difference was found between the partial face- and line-contact groups (p<0.001). Both tests revealed that partial face-contact implants are more prone to leakage than line-contact implants.

The effect of dynamic loading on bacterial microleakage of the dental implant fixture-abutment interface: An in vitro study

Aim

Bacterial micro leakage at implant-abutment interface under functional loading is an important factor, may lead to crestal bone loss and affect the long term success of dental implants. Due to the limited studies about the implant systems with a connection of Slip joint design, this study aimed to evaluate the effect of dynamic loading on bacterial leakage at the implant-abutment interface with slip joint connection.

Settings and Design

In vitro- comparative study.

Materials and Methods

A total of 20 implants and abutments with slip joint connections (Tapered Screw-Vent, 3.7 mm ×10 mm, Zimmer Dental, USA) was examined and depends on using functional loading were divided into two groups; loaded and unloaded. Initially, 10 μl of Brain Heart Infusion (BHI) culture broth was pipetted to the internal lumen of each implant, then the abutments were tightened to the fixtures and crowns were cemented. In the unloaded group, samples were immersed in E-Coli suspension for 5 days. In the loaded group, samples were immersed in microbial suspension under 500000 cycles using a cyclic load device. Following disconnection of fixtures and abutments, microbial samples were taken from the internal lumen of implants and colonies were counted. Data were analyzed using.

Statistical Analysis Used

Mann-Whitney statistical test, SPSS version 24.

Results

The mean rate of micro leakage in unloaded and loaded groups was 4000 CFU/ml and 27000 ± 31640 CFU/ml respectively. Bacterial colonies grew in 10% of unloaded samples and 50% of loaded samples. This difference was statistically significant. (P < 0.05).

Conclusions

Microbial micro leakage at the implant-abutment interface with slip joint design increased significantly after functional loading.

Factors Influencing Marginal Bone Loss around Dental Implants: A Narrative Review

Implant supported dental prostheses are increasingly used in dental practice. The aim of this narrative review is to present the influence of transmucosal surface of prosthetic abutment and implant on peri-implant tissue. The article describes causes of bone loss around the dental implant. Moreover, properties of different materials are compared and discussed. The advantages, disadvantages, and biomechanical concept of different implant-abutment connections are presented. The location of connections in relation to the bone level and the influence of microgap between the abutment and implant are described. Additionally, the implant abutments for cemented and screwed prosthetic restorations are compared. The influence of implant and abutment surface at the transmucosal level on peri-implant soft tissue is discussed. Finally, the biological aspect of abutment-implant connection is analyzed.