Comparative Evaluation of Changes in Microflora in Delayed and Immediate Implant Placement: An In vivo Study.

AIM: This study is aimed to compare and evaluate the changes in the microflora in immediate and delayed placed implants.
MATERIALS AND METHODS: In this study, the implant site sample was taken and assessed during different phases of treatment for delayed and immediate implants. They were looked for Streptococcus, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, and Fusobacterium nucleatum.
RESULTS: The results showed that Streptococci were found in a higher number in all the phases of the treatment. The presence of pathogenic organisms such as P. gingivalis and Fusobacterium, in considerable amounts, was seen in both the groups.
CONCLUSION: Thus, we conclude that implant mode of placement, delayed or immediate placement does not alter the flora of the oral cavity. Organisms present remains the same in all the phase of the treatment. To prevent the disease, one must continuously monitor the implant, with the increasing age changes, the microflora is continually changing in the oral cavity. The periodontal health should be assessed before the placement of the implant, followed by follow-ups after a set period for a better prognosis. Copyright:

INTRODUCTION

Today osseointegrated titanium implants are successfully used as abutments for the rehabilitation in edentulous or partly edentulous patients. The 5- or 10-year survival rates reported for dental implants range from 82% to 95%, while its success rate is 73.5%–93.9%. The diagnosis of a failing implant can, at times, be challenging.[1] Treatment of failed implant associated with bone loss is primarily due to bacteria-initiated disease, overheating of the bone at the preparation site and excessive loading of the implant.[2]

Few complications associated with this lower success of implant are peri-implant mucositis and peri-implantitis. The implant provides an oral cavity with a new artificial surface, prone to the formation of biofilm, just like a natural tooth. This biofilm triggers the inflammatory destruction of peri-implant tissue, known as peri-implantitis.[3] A 5–11-year study on implant reported that peri-implant mucositis affects 40%–90% of implants in 80% of subjects, while around 20% of implants develop peri-implantitis.[1]

Peri-implantitis was first considered as a complement of periodontitis, but the latest studies indicate that peri-implantitis pathology diverges from periodontal pathology.[4] Some studies suggest that peri-implantitis and peri-implant bone loss incidence was more in subjects with periodontitis associated tooth loss. Moreover, peri-implant and periodontal diseases have few common risk factors such as age, tobacco use, and levels of oral hygiene.[5] Thus, risk factors for the periodontal disease could also increase the risk of development of peri-implant disease confirm that both disorders share some etiopathogenic aspects. It is a well-established fact that microorganisms are the main etiological factor in the development of periodontal diseases. Hence, the composition of the microbiota in the peri-implant area may also influence the fate of an artificial fixture.[6]

There have been many studies that analyzed the microflora at the implant site and periodontitis. However, limited data are available regarding microflora of the peri-implant sulcus without clinical periodontitis. Therefore, this study is aimed to compare and evaluate the changes in the microflora in immediate and delayed placed implants. The main aim was to assess the prevalence of microflora preoperatively during the operative phase and maintenance phase.

MATERIALS AND METHODS

Approval of the study was obtained from the Ethical Committee of the institute. Written informed consent was taken from all patients that were included in the study. The study was conducted together by the department of oral surgery, prosthodontics and periodontics and implantology.

Inclusion criteria

The study consists of 50 patients, males and females, divided into two groups. Group I was formed 25 patients in with immediate implant placement, and Group II is formed by 25 patients, in which delayed implant was placed. The age of the patient ranges between 30 and 52 years. At least, one titanium implant (MKIII, Nobel Biocare) was placed in all the patients according to the manufacturer's protocol.

Exclusion criteria

Patients with the habit of smoking, alcohol, diabetes mellitus, immunosuppressive conditions, pregnancy, lactation, and systemic antibiotic therapy within 6 months before biofilm sampling or with an extensive fix or removable orthodontic or prosthetic appliance were excluded from the study.

Procedure

The materials and media used for the study were sterilized. One day before, sample collection and implant placement, complete mouth scaling, and polishing were done.

Sample collection

The sampling sites were isolated using cotton rolls and any subgingival plaque if the present was registered and removed with the curette. The bacteria samples were obtained by inserting sterilized number 30 paper points in the depth of the gingival sulcus (both mesial and distal side) of the implant site and from the vestibule of the edentulous site on the alveolar ridge. It was kept in the position for 60 s.

These paper points with stored in sterile transport vials. They were transported to the laboratory in a 1 ml anaerobic medium. The samples were looked for the growth of Streptococcus, Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, and Fusobacterium nucleatum blood agar, kanamycin blood agar, and kanamycin-vancomycin blood agar was used as a bacterial culture media in the study.

The formula used to calculate colonies was:

Colony-forming units/milliliter = (number of colonies × dilution factor)/volume of culture plate.

The samples were obtained in the following order:

Preoperative (before antibiotic regimen)

One day after implant placement

After suture removal

Two weeks after implant placement

At the time of abutment attachment

Two days after abutment attachment

Day of prosthesis placement

Two days after prosthesis placement

1 month follow-up

2 months follow-up.

Samples obtained from the delayed group were labeled from D1 to D10 and from the immediate group were labeled from I1 to I10.

RESULTS

The samples collected were looked for pathogenic microorganisms: Streptococcus, A. actinomycetemcomitans, P. gingivalis, P. intermedia, and F. nucleatum. The values of the microbiological analysis of both the groups (immediate and delayed) are given in Tables 1 and 2. Specific statistical tests were used for analyzing the data and for obtaining the results.

Table 1

Number of organisms in colony forming unit per millilitre in Group 1

Organism (CFU/ml)	I1	I2	I3	I4	I5	I6	I7	I8	I9	I10
Streptococcus	0.32×108	0.19×108	0.16×108	0.21×108	0.19×108	0.27×108	0.31×108	0.37×108	0.26×108	0.24×108
Aggregatibacter actinomycetemcom tans	0.02×108	Nil	Nil	Nil	Nil	Nil	Nil	Nil	Nil	Nil
Prevotella intermedia	0.02×108	Nil	Nil	Nil	Nil	Nil	Nil	Nil	Nil	Nil
Prevotella gingivalis	0.12×108	0.14×108	0.14×108	0.18×108	0.15×108	0.11×108	0.12×108	0.17×108	0.14×108	0.12×108
Fusobacterium nucleatum	0.27×108	0.13×108	0.11×108	0.12×108	0.16×108	Nil	0.13×108	0.11×108	0.11×108	0.15×108

CFU: Colony-forming unit

Table 2

Number of organisms in colony forming unit per millilitre in Group II

Organismc (CFU/ml)	D1	D2	D3	D4	D5	D6	D7	D8	D9	D10
Streptococcus	0.39×108	0.35×108	0.29×108	0.21×108	0.25×108	0.20×108	0.23×108	0.35×108	3.2×108	2.9×108
Aggregatibacter actinomycetemcom
itans	0.01×108	NG	NG	NG	NG	NG	NG	NG	NG	NG
Prevotella intermedia	0.09×108	NG	NG	NG	NG	NG	NG	NG	NG	NG
Porphyromonas gingivalis	0.11×108	0.16×108	0.15×108	0.12×108	0.15×108	0.11××108	0.12×108	0.15×108	0.11×108	0.13×108
Fusobacterium nucleatum	0.32×108	0.11×108	0.12×108	0.11×108	0.19×108	1.5×108	0.12×108	0.14×108	0.13×108	0.12×108

CFU: Colony-forming unit

Table 3 shows the mean percentage of colonies different organisms in Group I and Group II. In both, the group's Streptococci were seen in the higher titer as compared to P. gingivalis, Fusobacterium, P. intermedia, and A. Actinomycetemcomitans, which shows comparatively low titer. A comparison of the mean concentration of different organisms in the immediate implant shows a statistically significant result (Kruskal–Wallis, P < 0.001). Moreover, similarly, when the mean concentration of different organisms was observed in the delayed implant group, it was also statistically significant (Kruskal–Wallis, P < 0.001). However, when both the groups were compared to each other, the result was insignificant. These results show that there is no significant difference in the microflora of the immediate implant and delayed implants.

Table 3

Mean percentage of colonies of different organism

Organism (CFU/ml)	Group I (%)	Group 11 (%)
Streptococcus	43.7	47.2
Aggregatibacter actinomycetemcomitans	3.8	1.8
Prevotella intermedia	3.8	4.9
Porphyromonas gingivalis	24	21.4
Fusobacterium nucleatum	24.7	24.7

CFU: Colony-forming unit

DISCUSSION

Many factors are responsible for the success of the implant. One of the most critical factors responsible for the success of the implant is osseointegration. Early implant failure occurs due to inadequate osseointegration, and late failure is due to an inability to maintain osseointegration. The reason for early failures includes premature loading of the implant, surgical trauma, and bacterial infection. Late failures occur after prosthesis placement. Late failures occur due to many reasons. One primary reason is periimplantitis.[7] Various studies have shown the microflora associated with dental implants is the same as that of the tooth in a healthy mouth.[8] Quirynen et al.[9] in their research compared the plaque composition on the implants of fully edentulous patients with that of partially edentulous patients and concluded that the presence of natural teeth in the mouth influences the microflora around the implant.

Similarly, bacteria associated with failing implants have also been studied. Several studies have shown that microflora associated with a failing implant is similar to that of periodontal disease.[1011] Thus, subjects with periodontal disease are at significant risk for implant failure. Most of the microbial studies associated with implants are associated with the disease state of the periodontium. We conducted a study in which we evaluated the bacteriology associated with a peri-implant sulcus of patients with immediate and delayed implants without periodontal disease.

The samples from ten different phases of the treatment were analyzed. The results showed that In both groups, Streptococci were seen in the higher titer as compared to P. gingivalis, Fusobacterium, P. intermedia, and A. actinomycetemcomitans, which shows comparatively low titer. This can be attributed to the fact that Streptococcus is the normal commensal of the mouth, while other microorganisms are found in the pathologic state. Therefore, the titers of these cocci cells are more. The study also shows that microorganisms remain the same in healthy patients throughout the treatment process. Our results were in accordance with Quirynen et al.[9] who reported 65.3% cocci compared to other bacteria. P. gingivalis (21.4%–24%) and F. nucleatum (24.7%) was another predominant bacteria that were observed and are associated with periodontitis. Similar results were obtained by Mombelli et al.[11] in their study in healthy patients with implants. Cortelli et al.[6] in his research, found that P. gingivalis to be 12% and P. intermedia to be 22% in a healthy patient with implants that contradict our results as the value of P. intermedia in our study was very less ranging 3.8%–4.9% in Group 1 and Group 2. However in the same study, the number of P. gingivalis increased in mucositis and periimplantitis condition. This could be explained by the study conducted by Silverstein et al.[12] according to them, the microflora around the implant keeps on changing, and the same microorganism responsible for periodontitis causes peri-implantitis. Therefore, the periodontium around implant must be continuously monitored after implant placement.

Albertini et al.,[10] in their study, concluded that the implant surface might be colonized with pathogens different from periodontal bacteria. Opportunistic pathogens such as P. aeruginosa, S. aureus, and C. albicans may be associated with implant failure.

Our study shows an insignificant difference between microflora associated with immediate and delayed implants. The results were in accordance with the study conducted by Hiremath et al.[13] she concluded that the mode of implant placement does not alter the peri-implant microflora. Organisms observed preoperatively were present during the entire phase of the treatment.

Canullo et al.[14] analyzed the bacterial microflora inside the implant connection and in the peri-implant sulcus fluid of healthy implants after 5 years of functional loading. Their results showed that the implant connection gets contaminated after 5 years of the treatment. They also observed that the connection design influences bacterial activity levels, especially inside the implant connection.

CONCLUSION

Thus, we conclude that implant mode of placement, delayed or immediate placement does not alter the flora of the oral cavity. Organisms present remain the same in all the phase of the treatment. To prevent the disease, one must continuously monitor the implant with the increasing age changes the microflora is continually evolving in the oral cavity. The periodontal health should be assessed before the placement of the implant, followed by follow-ups after a set period for a better prognosis.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.