Assessment of Titanium Level in Submucosal Plaque Around Healthy Implants and Implants with Peri-implantitis: A Clinical Study.

BACKGROUND: The present study focused on assessing the level of titanium in submucosal plaque in the peri-implant area with peri-implantitis in comparison to healthy implants.
METHODOLOGY: Sixty patients with titanium dental implants were recruited. The degree of titanium in submucosal plaque around peri-implantitis and healthy implants was estimated using inductively coupled plasma mass spectrometry.
RESULTS: The mean ± standard deviation probing depth in Group I was 3.12 ± 1.1 and in Group II was 7.2 ± 2.5; gingival index was 0.64 ± 0.3 and 1.64 ± 0.8 in Group I and Group II, respectively. The plaque index was 0.82 ± 0.2 in Group I and 1.5 ± 0.6 in Group II. The mean plaque mass in Group I was 24.1 ± 3.8 ng/ul and 49.3 ± 6.4 ng/ul in Group II. The mean titanium level in Group I was 0.08 ± 0.02 μg and in Group II was 0.91 ± 0.04 μg. A highly significant difference between both groups was found (P < 0.05).
CONCLUSION: There was a significantly higher titanium level in submucosal plaque around dental implants with signs of peri-implantitis as compared to healthy dental implants. Copyright:

INTRODUCTION

Dental implants have revolutionarized the field of dentistry.[1] Earlier before the advent of dental implants, dentists rely on removable partial denture (RPD), fixed partial denture (FPD), or complete denture for the replacement of missing few or multiple teeth.[2] With the invention of dental implants, the limitation offer by FPD or RPD in the form of sensitivity caused by tooth preparation or cervical abrasion or mobility of adjacent teeth has been minimized.[3] Titanium dental implants have the ability to unite with the bone through structural and functional connections. Titanium dental implants offer excellent osseointegration, i.e., its ability to unite with the bone. One of the requirements of an ideal dental implant is its capability to resist corrosion.[4] Titanium leads to the development of titanium dioxide (TiO2) which is highly resistant to corrosion. It is one of the best biocompatible metals. Although it has superior properties of resistance to corrosion, a complete prevention cannot be ensured in the oral cavity.[5]

There is an alteration in the titanium implant due to the dissolution of titanium from the TiO2 layer. Factors such as increase in the level of caries causing bacteria such as Streptococcus mutans leads to the formation of lactic acid in the oral cavity, peri-implant tissues inflammation, etc.[6] It has been observed that there is a significantly higher concentration of S. mutans around implants with peri-implantitis in comparison to healthy teeth.[7] Considering this, the present study focused on assessing the level of titanium in submucosal plaque around implants with peri-implantitis as compared to healthy implants.

METHODOLOGY

The present case–control study was commenced after obtaining ethical clearance from the ethical clearance and review committee of the institute. The sixty enrolled subjects from the periodontics department were made aware of the study and their utilities and after convincing them, written consent for their participation in the study was obtained.

The following inclusion criteria such as the presence of atleast one healthy plus one implant with signs of peri-implantitis and presence of prosthetic part for atleast since 3 years was considered. Subjects with systemic illness, on long-standing steroids and antibiotics for the last 3 months were excluded. A thorough oral examination with assessment of gingival index, plaque index, and bleeding on probing and/or suppuration at six sites was done. Subjects with the occurrence of probing depths ≥5 mm, bleeding on probing and/or suppuration, and bone loss ≥2 mm were considered to have peri-implantitis. Collection of baseline and follow-up radiographs was done for assessment of bone loss. Healthy implants showed no signs of suppuration and clinical and radiographic bone loss. Two groups were formed based on the presence of healthy (Group I) and peri-implantitis implants (Group II).

Each implant site was curetted with mini-five 1–2 Gracey curettes for the collection of submucosal plaques. Samples thus obtained were stored in 500 μl sterile water in screw-cap tubes and frozen at the temperature of −-0°C. A 350 μl aliquot of the sample collected was used for quantification of titanium by inductively coupled plasma mass spectrometry (ICP-MS). DNA isolation and DNA quantification were performed with 150 μl aliquot to validate the amount of plaque in each sample. Data thus found from the above said methods were clubbed together and entered in MS Excel sheet and assessed statistically using Fisher's exact test and Mann–Whitney U test. A significance level was set below 0.05.

RESULTS

Table 1 shows that there were 16 males and 14 females in Group I and 12 males and 18 females in Group II. The mean age was 45.6 years in Group I and 42.3 years in Group II. The mean duration of dental implants in the oral cavity was 5.6 years in Group I and 5.2 years in Group II. The difference was found to be nonsignificant (P > 0.05).

Table 1

Distribution of implants

Parameters	Group I (healthy)	Group II (peri-implantitis)	P
Male: female	16:14	12:18	0.07
Age (years)	45.6	42.3	0.15
Duration of implants (years)	5.6	5.2	0.17

Table 2 and Graph 1 show that mean ± standard deviation (SD) probing depth in Group I was 3.12 ± 1.1 and in Group II was 7.2 ± 2.5; gingival index was 0.64 ± 0.3 and 1.64 ± 0.8 in Group I and Group II, respectively. The plaque index was 0.82 ± 0.2 in Group I and 1.5 ± 0.6 in Group II. A significant difference among parameters was found (P < 0.05).

Table 2

Assessment of parameters

Parameters	Mean±SD		P
	Group I	Group II
Probing depth	3.12±1.1	7.2±2.5	0.001
Gingival index	0.64±0.3	1.64±0.8	0.02
Plaque index	0.82±0.2	1.5±0.6	0.05

SD: Standard deviation

Graph 1

Assessment of parameters

Table 3 and Graph 2 show that the mean plaque mass in Group I was 24.1 ± 3.8 ng/ul and 49.3 ± 6.4 ng/ul in Group II. A highly significant difference between both groups was found (P < 0.05).

Table 3

Assessment of plaque mass in both groups

Plaque mass (ng/ul)	Mean±SD	P
Group I	24.1±3.8	0.001
Group II	49.3±6.4

SD: Standard deviation

Graph 2

Assessment of plaque mass in both groups

Table 4 and Graph 3 show that the mean titanium level in Group I was 0.08 ± 0.02 μg and in Group II was 0.91 ± 0.04 μg. A highly significant difference between both groups was found (P < 0.05).

Table 4

Assessment of titanium level in both groups

Titanium level (μg)	Mean±SD	P
Group I	0.08±0.02	0.001
Group II	0.91±0.04

SD: Standard deviation

Graph 3

Assessment of titanium level in both groups

DISCUSSION

Dental implants are one of the highly opted and recommended dental treatments for partially or completely edentulous patients.[8] It is the treatment of choice among patients as well as dentists. The increased use is because of high success rate as compared to FPD and RPD. Titanium dental implants have maximum strength, chemical stability, wear resistance, and excellent fatigue.[9] Due to the formation of 3–5 nm thick oxide layer on titanium implants, it has higher corrosion resistance. 47 Ti and 49 Ti in the prevalence of 7.3% and 5.5%, respectively, may be used for quantification with ICP-MS without having problems with chromium, calcium, and vanadium isotopes.[10] It is evident that porphyromonas gingivalis has high tendency for attachment to corroded titanium implants. It is further ascertained that the electrical conductivity of titanium in the occurrence of oral bacteria provides a closed circuit that may enhance the biocorrosive process.[11] The present study assessed the level of titanium in submucosal plaque around implants with peri-implantitis as compared to healthy implants.

In this study, we enrolled 60 patients with the presence of healthy as well as dental implants with the clinically and radiographically presence of signs of peri-implantitis. Both sites were mentioned as Group I (healthy implants) and Group II (dental implants with peri-implantitis). We found that the mean age in Group I and in Group II was 45.6 years and 42.3 years, respectively. The mean duration of dental implants in the oral cavity was 5.6 years in Group I and 5.2 years in Group II. Group I comprised of 16 males and 14 females; Group II had 12 males and 18 females. Safioti et al.[12] conducted a study on 30 patients in which submucosal plaque from 20 implants with peri-implantitis and 20 healthy implants was collected and subjected to coupled plasma mass spectrometry (ICP-MS) to determine levels of titanium. Implants with peri-implantitis revealed mean titanium levels of 0.85 ± 2.47 and those with healthy implants showed 0.07 ± 0.19 which was significantly higher (P < 0.05).

We observed that mean ± SD probing depth in Group I was 3.12 ± 1.1 and in Group II was 7.2 ± 2.5; gingival index was 0.64 ± 0.3 and 1.64 ± 0.8 in Group I and Group II, respectively. The plaque index was 0.82 ± 0.2 in Group I and 1.5 ± 0.6 in Group II. Pettersson et al.[13] conducted an in vivo animal study on digs and evaluated the quantity of titanium discharged around the bone during placement of implants with different surface structures using ICP atomic emission spectroscopy. Implant surface was observed with scanning electron microscopy (SEM), before and after the insertion into the bone. Ti was grounded to the surrounding bone on the placement of a dental implant and the surface roughness of the implant augmented the quantity of Ti observed. Diameter and total implant area were of less significance for the Ti discharged to the bone. No remarkable damage to the implant surfaces could be observed in SEM after insertion.

We found that the mean plaque mass in Group I was 24.1 ± 3.8 ng/ul and 49.3 ± 6.4 ng/ul in Group II. The mean titanium level in Group I was 0.08 ± 0.02 μg and in Group II was 0.91 ± 0.04 μg. Olmedo et al.[14] found a higher concentration of titanium in the peri-implantitis patients in comparison to healthy implants as determined by exfoliative cytology. Senna et al.[15] observed detectable fractures and chipping of the porous structure at the TiUnite surface with the help of scanning electron microscope (SEM) on both inspected surfaces, but in a much increased content on the TiU surfaces.

The shortcoming of the study was small sample size. A short follow-up was done.

CONCLUSION

The authors found that there was a significantly higher titanium level in submucosal plaque around dental implants with signs of peri-implantitis as compared to healthy dental implants.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.