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

ABSTRACT

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.

INTRODUCTION

Despite the high success rates in the osseointegration of dental implants, numerous issues with surgical methods and mechanical microbiological elements have been brought up. The most recent and frequent disease along a dental implant is peri-implantitis.[1]

The creation of the two-stage implant systems faces significant difficulties due to microbial seepage at the implant–abutment link.[2] Gaps and voids that occur between the implant and the abutment are the main sources of microbiological leakage. This then starts the inflammatory processes around the implant. The degree of bacterial colonization involving implants and abutments has been found to be influenced by fit precision between the fixture and abutment, and micromovements between the connected components during mastication.[3]

The current research was done to evaluate bacterial leakage of two types of internal implant–abutment associations.

MATERIALS AND METHODS

The current in vitro research was done in the Prosthodontic Department, at Mallareddy Dental College. The study protocol was approved by the Institutional Ethical Committee.

Twenty dental implants (Nobel Biocare, Switzerland) (3.0 mm × 11.5 mm) are categorized into two groups with 10 samples in each group: 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. Then, sterile paper points were used to check for bacterial contamination on the internal surfaces of the implants. These paper points were submerged in sterile brain–heart infusion broth-filled test tubes. On blood agar plates, a culture was created from the broth, and the plates were incubated at 37°C for 24 h. Gram stain and biochemical processes were used to distinguish between the generated colonies.

A 15 kV electron microscope was used to measure the microgap in all samples. Four spots on each sample were used to assess and measure the microgap’s size. Results thus obtained were statistically evaluated with SPSS version 22.0 with Mann–Whitney U-test and Tukey’s honesty at P < 0.05.

RESULTS

Table 1 showed that the mean Log₁₀ CFU in group A was 8.4 and in group B was 7.2. The variation between both groups was seen to be considerable. Microgap was more in group B compared to group A [Table 2].

Table 1.

Comparison between Log10 CFU in both groups

Groups	Mean	P
Group A	8.4±0.1	0.05
Group B	7.2±0.3

Table 2.

Comparison of mean microgap in both groups

Groups	Mean	P
Group A	6.5±0.4	0.05
Group B	9.7±0.3

DISCUSSION

The implant–abutment mismatch creates microscopic gaps that facilitate saliva and oral bacteria leakage and causes them to collect at the implant–abutment link, which results in slight bone loss. Marginal bone loss can harm the outcome of implant therapy.[4] The bacterial contamination could be affected by the gap sizes. The degree of contamination is influenced by the fit’s accuracy, the amount of applied micro-movement, and torque.[1,3,4]

The rate of bacterial leakage did not considerably alter over time, according to Khajavi et al., but the type of connection had a major impact on it.[4] Faria et al. evaluated bacterial leakage along the implant–abutment interface, comparing three types of connections: EH, IH, and MT. A colony of Escherichia coli was inoculated in the apical portion of abutment screws. There were no differences among different connection types.[5]

Nassar et al. observed that internal hexagon implants had a greater average Log₁₀ CFU than tri-lobe implants.[6] It has been found by many researchers that microscopic space involving implant and abutment may be the site of bacterial penetration.[5,7]

In the current study, microbial leakage was more in group B compared to group A, which has resulted in more microbial leakage. Further studies are needed to validate the result.

CONCLUSION

Researchers discovered that germs may infiltrate the tiny gap between an implant and an abutment. In comparison to dental implants fixtures with a tri-lobe internal connection, dental implants fixtures with an internal hexagonal geometry had a much higher Log10 CFU.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.