NIH Public Access Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
NIH-PA Author Manuscript
Published in final edited form as: Forum Implantol. 2012 ; 8(2): 17–21.
Clinical Report on the Use of Implant Therapy in Patients with Type 2 Diabetes Thomas W. Oates, DMD, PhD and Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX Adriana Vargas, DDS, MPH, MS Department of Comprehensive Dentistry, University of Texas HealthScience Center at San Antonio, San Antonio, TX
NIH-PA Author Manuscript
As discussed in the review of dental implant survival for patients with diabetes in this issue of Forum Implantologicum, we really do not know the full impact of diabetes on dental implant therapy. Over the past 10 years, we have undertaken clinical studies in hopes of clarifying this question. While the review highlights the limitations in our current knowledge and the progress being made, the goal herein is to present some of our clinical observations as we continue to treat and study patients with diabetes. Poor glycemic control has long been considered a contraindication to dental implant therapy. The effects are thought to include compromised wound healing, increased risk of infection associated with a diminished immune response and alterations in bone metabolism. These concerns have been well documented in animal models for diabetes and are consistent with many of the clinical ramifications of the disease. However, direct evidence for these concerns has not been established in the oral environment for diabetes patients.
GLYCEMIC CONTROL AND WOUND HEALING NIH-PA Author Manuscript
One common concern for diabetes patients is compromised wound healing and postoperative infection. To examine this concern, we have provided surgical implant therapy to patients with glycated hemoglobin (HbA1c) levels over 12% and peri-operative blood glucose levels over 350mg/dl, and evaluated wound healing over the first week following implant surgery. Figure 1 shows our findings for early healing complications relative to glycemic control for over 100 patients. In evaluating these patients, we were unable to identify a difference in early healing (one week following implant surgery) based on diabetes or glycemic control and had only minor complications noted for any of the patients, with no complications requiring additional care. Having no good information to guide our care of these patients at the outset, we did have concerns for infection and compromised wound healing. Therefore our clinical protocol had two antimicrobial components. Clinical management of these patients included post-
Corresponding Author: Thomas Oates DMD, PhD, Department of Periodontics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, [email protected].
Oates and Vargas
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operative antibiotics for one week (typically amoxicillin 500 mg three times per day) and chlorhexidine mouth rinse for at least two weeks.
NIH-PA Author Manuscript
Figures 2 and 3 illustrate typical healing patterns seen for these patients. The first patient (Fig. 2) presented with moderate to poor glycemic control (HbA1c=8.5%). The second patient (Fig. 3) had poor glycemic control (HbA1c=10.1%) and highly elevated perioperative blood glucose levels. Consistent with our general findings (Fig. 1), both patients had no significant post-operative complications with soft tissue healing.
IMPLANT INTEGRATION
NIH-PA Author Manuscript
As we have progressed in our understanding of the effects of diabetes on implant integration, we have relied on resonance frequency analysis (RFA) to assess changes in implant stability over the period of implant integration (Oates et al., 2009). It appears from our studies that there is a greater decrease in implant stability over the first few months following placement for patients with diabetes (Fig. 4a) along with a significant delay to the establishment of increased levels of integration (Fig. 4b). These compromises in implant integration are directly related to glycemic control, consistent with animal models of diabetes and bone metabolism. In addition, our study identified HbA1c levels over 8.0% as being related to these compromises in integration. Interestingly, this is the same threshold of glycemic control that has been associated with other systemic co-morbidities. It appears that the levels of implant integration do return to levels consistent with that of non-diabetic patients within the first four to six months following placement. Awareness of this delay in bone integration provides our current rationale for delaying restoration/loading of implants for those diabetes patients who lack good control for four months following placement compared to the manufacturer’s recommendation of six to eight weeks in healthy patients. Based on our earlier findings, it appears that bone-type effects also play a role in this process as less dense bone tends to have greater decreases and longer delays before establishing stability levels greater than at placement.
LONG-TERM EFFECTS NIH-PA Author Manuscript
As we have now extended our evaluation of these diabetes patients over longer time periods, we are finding few effects related to diabetes and glycemic control. The majority of our patients have received two mandibular implants with overdenture prostheses (Fig. 5). Within this restorative protocol, the implants for patients with diabetes appear to be doing just as well as those in non-diabetic patients in terms of stability (RFA) or peri-implant health. Figure 6 presents one of our diabetes patients with more significant healing complications following implant placement. This poorly controlled diabetes patient (HbA1c=10.6% at the time of surgery) lost one of the healing caps following implant placement, and demonstrated moderate levels of tissue inflammation and marginal flap necrosis. As we have followed the patient, glycemic control continues to be high (HbA1c>9.5%), which may be a potential concern for the patient’s susceptibility to peri-implantitis. While there are signs of periimplant mucositis, after five years there are no signs of bone loss, implant stability remains
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
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at high levels consistent with the initial loading, and the implant-supported denture remains highly functional and certainly appreciated by the patient.
NIH-PA Author Manuscript
CONCLUSION At the present time it remains unclear as to the most appropriate implant protocol for patients with diabetes. Based on our experiences, studies, and interpretation of literature, diabetes patients may be appropriate candidates for implant therapy independent of glycemic control. However, the clinical protocols appropriate to the systemic condition and glycemic levels need to be fully considered. There is no doubt that our patients are well served with implant therapy. Our biggest challenge is to make sure we can provide these benefits to the greatest number of patients, especially those with the greatest need. Diabetes patients who are critically dependent on dietary management of their disease may well represent a great need for improved oral health and function and deserve our careful consideration.
References NIH-PA Author Manuscript
Oates TW, Dowell S, Robinson M, McMahan CA. Glycemic control and implant stabilization in type 2 diabetes mellitus. Journal of Dental Research. 2009; 88:367–371. [PubMed: 19407159]
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 4
NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 1.
Patients with and without diabetes (as determined using HbA1c levels) were evaluated one week following implant surgery for placement of two or more implants in the mandible. There were no significant differences noted for any of the post-operative complications assessed. Complications other than days with pain were scaled as 0=absent, 1=slight, 2= moderate, and 3=severe. VIS represents a visual inflammation score using clinical photographs evaluated by three masked clinicians
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 5
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 2.
This case documents the early clinical healing for a 62-year-old Hispanic female who received two dental implants for a mandibular overdenture. She had been diagnosed with type 2 diabetes 10 years previously and was attempting to manage her disease with oral medications and diet. Her HbA1c at the time of surgery was 8.5% and her fasting plasma glucose was 186mg/dl a: Transgingival implant placement following surgery b: One week following implant surgery c: Four weeks following implant surgery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
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d: Four months following implant surgery
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
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NIH-PA Author Manuscript NIH-PA Author Manuscript Fig. 3.
NIH-PA Author Manuscript
This is a 55-year-old Hispanic male with type 2 diabetes over 10 years with poor glycemic control. HbA1c at the time of surgery was 10.1% and his FPG=356 mg/dl a: One week following single implant placement for a mandibular partial overdenture b: Four weeks following implant surgery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
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NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 4.
NIH-PA Author Manuscript
a: Percent maximum decrease in stability from implant placement. Decreases in implant stability in direct relation to HbA1c levels. * indicates significant changes from baseline levels of stability using Resonance Frequency Analysis b: Weeks until stability levels return to levels above the time of placement. Delays in the return of implant stability to levels found at baseline in direct relation to HbA1c levels. * indicates significant differences from non-diabetic patients
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
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NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 5.
This is a 64-year-old Hispanic male with well controlled type 2 diabetes (HbA1c=6.6%) at the time of functional loading of the implants
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
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NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 6.
Caucasian, 63-year-old female patient with poor glycemic control (HbA1c=10.6%) a: At the time of implant placement b: One week following implant placement c: Three months following implant placement d: Five years following implant placement and over four-and-a-half years following implant prosthesis delivery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
NIH-PA Author Manuscript
Published in final edited form as: Forum Implantol. 2012 ; 8(2): 17–21.
Clinical Report on the Use of Implant Therapy in Patients with Type 2 Diabetes Thomas W. Oates, DMD, PhD and Department of Periodontics, University of Texas Health Science Center at San Antonio, San Antonio, TX Adriana Vargas, DDS, MPH, MS Department of Comprehensive Dentistry, University of Texas HealthScience Center at San Antonio, San Antonio, TX
NIH-PA Author Manuscript
As discussed in the review of dental implant survival for patients with diabetes in this issue of Forum Implantologicum, we really do not know the full impact of diabetes on dental implant therapy. Over the past 10 years, we have undertaken clinical studies in hopes of clarifying this question. While the review highlights the limitations in our current knowledge and the progress being made, the goal herein is to present some of our clinical observations as we continue to treat and study patients with diabetes. Poor glycemic control has long been considered a contraindication to dental implant therapy. The effects are thought to include compromised wound healing, increased risk of infection associated with a diminished immune response and alterations in bone metabolism. These concerns have been well documented in animal models for diabetes and are consistent with many of the clinical ramifications of the disease. However, direct evidence for these concerns has not been established in the oral environment for diabetes patients.
GLYCEMIC CONTROL AND WOUND HEALING NIH-PA Author Manuscript
One common concern for diabetes patients is compromised wound healing and postoperative infection. To examine this concern, we have provided surgical implant therapy to patients with glycated hemoglobin (HbA1c) levels over 12% and peri-operative blood glucose levels over 350mg/dl, and evaluated wound healing over the first week following implant surgery. Figure 1 shows our findings for early healing complications relative to glycemic control for over 100 patients. In evaluating these patients, we were unable to identify a difference in early healing (one week following implant surgery) based on diabetes or glycemic control and had only minor complications noted for any of the patients, with no complications requiring additional care. Having no good information to guide our care of these patients at the outset, we did have concerns for infection and compromised wound healing. Therefore our clinical protocol had two antimicrobial components. Clinical management of these patients included post-
Corresponding Author: Thomas Oates DMD, PhD, Department of Periodontics, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, [email protected].
Oates and Vargas
Page 2
operative antibiotics for one week (typically amoxicillin 500 mg three times per day) and chlorhexidine mouth rinse for at least two weeks.
NIH-PA Author Manuscript
Figures 2 and 3 illustrate typical healing patterns seen for these patients. The first patient (Fig. 2) presented with moderate to poor glycemic control (HbA1c=8.5%). The second patient (Fig. 3) had poor glycemic control (HbA1c=10.1%) and highly elevated perioperative blood glucose levels. Consistent with our general findings (Fig. 1), both patients had no significant post-operative complications with soft tissue healing.
IMPLANT INTEGRATION
NIH-PA Author Manuscript
As we have progressed in our understanding of the effects of diabetes on implant integration, we have relied on resonance frequency analysis (RFA) to assess changes in implant stability over the period of implant integration (Oates et al., 2009). It appears from our studies that there is a greater decrease in implant stability over the first few months following placement for patients with diabetes (Fig. 4a) along with a significant delay to the establishment of increased levels of integration (Fig. 4b). These compromises in implant integration are directly related to glycemic control, consistent with animal models of diabetes and bone metabolism. In addition, our study identified HbA1c levels over 8.0% as being related to these compromises in integration. Interestingly, this is the same threshold of glycemic control that has been associated with other systemic co-morbidities. It appears that the levels of implant integration do return to levels consistent with that of non-diabetic patients within the first four to six months following placement. Awareness of this delay in bone integration provides our current rationale for delaying restoration/loading of implants for those diabetes patients who lack good control for four months following placement compared to the manufacturer’s recommendation of six to eight weeks in healthy patients. Based on our earlier findings, it appears that bone-type effects also play a role in this process as less dense bone tends to have greater decreases and longer delays before establishing stability levels greater than at placement.
LONG-TERM EFFECTS NIH-PA Author Manuscript
As we have now extended our evaluation of these diabetes patients over longer time periods, we are finding few effects related to diabetes and glycemic control. The majority of our patients have received two mandibular implants with overdenture prostheses (Fig. 5). Within this restorative protocol, the implants for patients with diabetes appear to be doing just as well as those in non-diabetic patients in terms of stability (RFA) or peri-implant health. Figure 6 presents one of our diabetes patients with more significant healing complications following implant placement. This poorly controlled diabetes patient (HbA1c=10.6% at the time of surgery) lost one of the healing caps following implant placement, and demonstrated moderate levels of tissue inflammation and marginal flap necrosis. As we have followed the patient, glycemic control continues to be high (HbA1c>9.5%), which may be a potential concern for the patient’s susceptibility to peri-implantitis. While there are signs of periimplant mucositis, after five years there are no signs of bone loss, implant stability remains
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 3
at high levels consistent with the initial loading, and the implant-supported denture remains highly functional and certainly appreciated by the patient.
NIH-PA Author Manuscript
CONCLUSION At the present time it remains unclear as to the most appropriate implant protocol for patients with diabetes. Based on our experiences, studies, and interpretation of literature, diabetes patients may be appropriate candidates for implant therapy independent of glycemic control. However, the clinical protocols appropriate to the systemic condition and glycemic levels need to be fully considered. There is no doubt that our patients are well served with implant therapy. Our biggest challenge is to make sure we can provide these benefits to the greatest number of patients, especially those with the greatest need. Diabetes patients who are critically dependent on dietary management of their disease may well represent a great need for improved oral health and function and deserve our careful consideration.
References NIH-PA Author Manuscript
Oates TW, Dowell S, Robinson M, McMahan CA. Glycemic control and implant stabilization in type 2 diabetes mellitus. Journal of Dental Research. 2009; 88:367–371. [PubMed: 19407159]
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 4
NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 1.
Patients with and without diabetes (as determined using HbA1c levels) were evaluated one week following implant surgery for placement of two or more implants in the mandible. There were no significant differences noted for any of the post-operative complications assessed. Complications other than days with pain were scaled as 0=absent, 1=slight, 2= moderate, and 3=severe. VIS represents a visual inflammation score using clinical photographs evaluated by three masked clinicians
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 5
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 2.
This case documents the early clinical healing for a 62-year-old Hispanic female who received two dental implants for a mandibular overdenture. She had been diagnosed with type 2 diabetes 10 years previously and was attempting to manage her disease with oral medications and diet. Her HbA1c at the time of surgery was 8.5% and her fasting plasma glucose was 186mg/dl a: Transgingival implant placement following surgery b: One week following implant surgery c: Four weeks following implant surgery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
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d: Four months following implant surgery
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
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NIH-PA Author Manuscript NIH-PA Author Manuscript Fig. 3.
NIH-PA Author Manuscript
This is a 55-year-old Hispanic male with type 2 diabetes over 10 years with poor glycemic control. HbA1c at the time of surgery was 10.1% and his FPG=356 mg/dl a: One week following single implant placement for a mandibular partial overdenture b: Four weeks following implant surgery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 8
NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 4.
NIH-PA Author Manuscript
a: Percent maximum decrease in stability from implant placement. Decreases in implant stability in direct relation to HbA1c levels. * indicates significant changes from baseline levels of stability using Resonance Frequency Analysis b: Weeks until stability levels return to levels above the time of placement. Delays in the return of implant stability to levels found at baseline in direct relation to HbA1c levels. * indicates significant differences from non-diabetic patients
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 9
NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 5.
This is a 64-year-old Hispanic male with well controlled type 2 diabetes (HbA1c=6.6%) at the time of functional loading of the implants
NIH-PA Author Manuscript Forum Implantol. Author manuscript; available in PMC 2014 October 15.
Oates and Vargas
Page 10
NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript
Fig. 6.
Caucasian, 63-year-old female patient with poor glycemic control (HbA1c=10.6%) a: At the time of implant placement b: One week following implant placement c: Three months following implant placement d: Five years following implant placement and over four-and-a-half years following implant prosthesis delivery
Forum Implantol. Author manuscript; available in PMC 2014 October 15.
