A Comparative Study Evaluating Implant Success and Bone Loss in Diabetes and Nondiabetes.

BACKGROUND: Diabetes is seen to be associated with increased rate of failure of implants. The implant failure can be categorized as ailing, failing, and failed implants. The review of literature did not form any consensus on the effect of diabetes on the implant success rates. The reason we found was many confounding factors and nonconsideration of glycemic status of diabetic patients. Hence, in our study, we eliminated the confounding factors and took glycemic index in consideration.
MATERIALS AND METHODS: Forty-six participants were included in this study, out of which 26 were nondiabetic and 20 diabetic. Diabetics were further divided into two groups based on the HBA1C values, as controlled and uncontrolled diabetics.
RESULTS: We found that the uncontrolled diabetics had highest rate of implant failure as compared to other two groups. Furthermore, the controlled diabetics and nondiabetics had similar implant successes and failure rates.
CONCLUSION: This suggests that controlled diabetics are comparable to nondiabetics in terms of implant success rates. Copyright:

INTRODUCTION

The choice of implants for the replacement of missing teeth is now growing in India. More and more people are opting implant for the replacement of teeth. Implants allow the replacement of missing teeth by the process described by Brane mark in 1983 and are known as osteointegration.[1]

Many factors affect the process of osteointegration, which includes personal habits such as smoking and presence of underlying systemic diseases such as osteoporosis and diabetes.

Diabetes mellitus (DM) can be broadly classified as type 1 and type 2, but this is just a very broad criterion; there are many other types of DM which does not fit into these two categories, such as gestational and maturity-onset diabetes of the young.

Diabetic complications includes microvascular changes like neuropathy, retinopathy, nephropathy also gross changes as increased periodontitis, tooth loss, delayed wound healing and higher response to infection.[2] Higher rates of implant failure, impaired osseointegration, and increased risk of peri-implantitis are seen to be associated with diabetes.[3]

Peri implantitis is classified as early, moderate, and advanced.

Early implantitis is defined as probing depth ≥4 mm and bone loss up to <25% of the implant length measured from time of prosthesis loading to current radiograph.

Moderate implantitis is defined as probing depth ≥6 mm and bone loss up to 25%–50% of the implant length measured from time of prosthesis loading to current radiograph.

Advanced implantitis is defined as probing depth ≥8 mm and bone loss >50% of the implant length measured from time of prosthesis loading to current radiograph.[4]

This study focuses on the comparison of implant success rate in diabetics and nondiabetic implant patient.

MATERIALS AND METHODS

All patients who received dental implant treatment were included in the study according to the selection criteria.

Patients who were medically healthy with no other systemic disease rather than diabetes, and who were received Nobel Biocare TiUnite surface bone level implants were included in the study.

Radiograph were required at time of placement and post operative follow-up upto 12 months. Only single implant crown tooth was included in the study.

The exclusion criteria were set to avoid any confounding factor. Patients with habit of smoking, aged above 60 years suffering from aggressive periodontitis, and any other disease except DM were excluded from the study. Patients having multiple and implant-supported bridge were excluded from the study.

All the participants were then divided into nondiabetic and diabetic group. Group II was further divided into Group II-A (controlled diabetics with HBA1C <8) and Group II-B (uncontrolled diabetics with HbA1c ≥8). All the data were collected and tabulated.

RESULTS

A total of 46 participants were included in this study, out of which 26 were nondiabetic and were placed in Group I and remaining diabetic participants were placed in Group II. Group II was further divided into II-A the controlled diabetic group and Group II-B uncontrolled diabetic group and consist of 12 and 8 participants, respectively.

The criteria for controlled and uncontrolled diabetics group were decided by the HbA1C values.

Table 1 shows the demographic data. Of 46 participants, 28 were males and 18 were females.

Table 1

Demographic data

S. No	Group I (n=26)	Group II (n=20)
		Group II-A (n=12)	Group II-B (n=8)
Male	15	8	5
Female	11	4	3
Total	26	12	8
HbA1c value		7.6±1.12	9.8±1.10

HbA1c: Glycated hemoglobin

Table 2 shows the overall outcomes of the implants placed. Of 26 patients in Group I, 14 went uncomplicated, 1 failed, and 6 ailing. In Group II-A out of 12, 7 cases went uncomplicated, 1 failed, and 2 were in ailing category; in Group II-B, out of 8, 4 failed, 3 ailing, and 1 went uncomplicated. The rate of uncomplicated cases was least in the uncontrolled diabetic group, suggesting that the uncontrolled diabetics are more at risk for failing implants. When the collective comparison of Group II was done with Group I, no significant difference was found as Group II collectively includes both controlled and uncontrolled diabetics. When Group II-A and Group II-B were compared, the P = 0.00614, which was statistically significant. This suggests that the rate of failure in uncontrolled diabetics is significantly more as compared to the controlled diabetics.

Table 2

Final outcomes after implant placement

	Group I	Group II
		II-A	II-B
N	26	12	8
Failed	1	1	4
Ailing	6	2	3
Uncomplicated	14	7	1
Percentage complicated	46.15	25	87.5
Z test
Comparison of Groups I and II	P=0.1074. The result is not significant at P<0.05
Groups I and II-A	P=0.89656. The result is not significant at P<0.05
Groups I and II-B	P=0.00236. The result is significant at P<0.05
Groups II-A and II-B	P=0.00614. The result is significant at P<0.05

When Group I was compared with Group II-A, no significant difference was seen in the failure rate, suggesting that the controlled diabetics were comparable to nondiabetics and the complication rate in controlled diabetics is similar to nondiabetics.

When Group I was compared with Group II-B, significant difference was found in the failure rate, suggesting that uncontrolled diabetics have significantly more failure rate as compared to nondiabetics.

Table 3 shows the comparison of implant failure with diabetic and nondiabetic group, according to the clinical features and the treatment failures. Group I showed 1 failed implant, with radiographic bone loss at Stage 2 and Guided Bone Regeneration was unsuccessful and the implant was removed within 3 years of placement. In Group II-A also, there was 1 failed implant, purulence in 6 months was seen in that case and the implant was removed before 1 year. In Group II-B, there were total 4 implant failures out of 8, and hence, the failure rate was 50% in case of uncontrolled diabetic group.

Table 3

Comparison of implant failure with diabetic and nondiabetic group

Clinical features of implant failure/ailing implants	Out come	Diabetic Group I	Nondiabetic Group II
			II-A (n=12)	II-B (n=8)
Purulence and swelling at 2 weeks	Lost by 1 month	-	-	1
Purulence and swelling at 3 weeks	Removed between 6-10 months
Gingival abscess at 6 weeks	Removed by 1-2 months			1
Purulence in 6 months	Removed before 1 year		1	1
Radiographic bone loss at Stage 2, GBR unsuccessful	Removed within 3 years	1
Became mobile and develop bleeding on probing and pocket	Removed within 2 years			1
Total		1	1	4
Percentage failed implants		3.8	16.66	50

GBR: Guided bone regeneration

Table 4 shows the comparison of ailing implants corrected with treatment. In Group I, there were total 6 ailing implants; out of them, 2 cases were having fistula around cover screw was found at 5–8 months follow up. Two of them were found to have fistula and difficulty in eating at 5–10 months and were treated by open flap debridement and GBR. In one case, there was swelling seen in 1 month and was treated by antibiotics, and another one case was treated by antibiotics and open flap debridement for fistula and purulence which was observed at 6 months. In Group II-A, there were 2 ailing implants out of which one developed fistula in 5–8 months and suffered from difficulty in eating and was treated by open flap debridement and GBR and another one developed bleeding on probing and suppuration within 2 years and was treated by open flap debridement and GBR.

Table 4

Comparison of ailing implants corrected with treatment

Implant infections	Time for bone loss	Diabetic Group I	Nondiabetic Group II
			II-A	II-B
Swelling treated with an antibiotic	1 month	1
Antibiotics and open flap debridement for fistula and purulence	4-6 months	1		-
Fistula around cover screw, early Stage 2 was done	5-8 months	2		1
Fistula difficulty in eating (open flap debridement and GBR)	5-10 months	2	1	2
Bleeding on probing and suppuration (open flap debridement and GBR)	1-2 years		1
Total		6	2	3
Percentage of ailing implants		23	16.66	37.5

GBR: Guided bone regeneration

There were total 3 ailing implants out of which 2 developed fistula and difficulty in eating and was treated by open flap debridement and GBR and 1 developed fistula around cover screw and early Stage 2 was done.

DISCUSSION

A total of 46 participants were included in the study out of which 26 were nondiabetic and remaining 20 were diabetic. Diabetic group was further divided further into 2 groups, controlled and uncontrolled group.

After statistical analysis, it was observed that the nondiabetic group and controlled diabetic group were comparable in terms of success rate. The highest rate of failure was observed in the diabetic group.

Increased periodontitis leading to tooth loss, delayed wound healing impaired osseointegration, and increased risk of peri-implantitis leading to higher levels of implant failure have been reported in the diabetic patients;[23] these results of Measely and Buser are in synchronization with our results.

Chrcanovic did not found any significant difference in implant failure rates of diabetics and nondiabetics.[5]

A meta-analysis conducted by Shi et al. in 2016 found no significant difference in the failure rates of implants in controlled and uncontrolled diabetics, but in this study, the effects of confounding factors such as smoking, age, periodontitis, and systemic disease were not considered, also, an overlap in HBA1c values was seen between 7 and 8, and these cases were allocated to either of the groups without any defined criteria, this could be one of the many reasons for getting a significant difference.[6] Our study has advantage in the fact that any confounding factor was eliminated and not included in the study, and hence, there was no other factor affecting our results. Another study conducted by Chen did not found any significant effect of diabetes on implant failures, and they took smoking, radiotherapy, diabetes, and osteoporosis into account, but specific type of diabetes was not differentiated in the study.[7]

Oates and Huynh-Ba in 2012[8] reviewed 16 studies and found no consensus related to the implant failure in diabetic patients. Another study conducted by him in 2013 failed to show that raised glycemic levels even up to 13.3% had any significant effect on implant survival in patients with type 2 diabetes.[9] They also excluded smoking, history of bisphosphonate use, pregnant women, untreated oral infection, and grafted sites.

Rosen et al. in 2013[10] described late bone loss as peri-implantitis. The incidence of peri-implantitis depending ranges from 11.3% to 47.1% as per Koldsland et al.[11] and 19%–65% as per the study was conducted by Derks and Tomasi.[12]

Implant survival rate of 80% in type 1 diabetics and 90% in type 2 diabetics was found in the study conducted by Araújo Nobre et al.[13]

Hyperglycemics were found to have decreased levels of osteointegration in untreated type 1 diabetes in a study conducted by Siqueira, but no such finding was observed by Oates et al. in his study[9] conducted on type 2 diabetics.

Study conducted by Mombelli and Cionca in 2006 found that the failure of implants in diabetics occurs early and when the glycemic control is poor, these results are in consistence with our results.[14]

CONCLUSION

Diabetes is often associated with impaired wound healing resulting in failure of dental implants, but the studies conducted either did not take into consideration of confounding factors or the type of diabetes. In our study, we excluded all the patient's with any comorbidity and patient's with any personal habits, thus reducing the confounding factor's to minimum, also we took in consideration the patient's with controlled and uncontrolled diabetics on the basis of HBA1c and found that the patients having good glycemic control were as good as nondiabetics, but the group having uncontrolled diabetes had a higher rate of implant failure.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.