Accumulated Bone Loss Research Articles

Age-related changes in lumbar bone mineral density measured using quantitative computed tomography in healthy female cynomolgus monkeys.

Cynomolgus monkeys are widely used in studies related to osteoporosis, and there is no evidence of age-related changes in volumetric bone mineral density (vBMD) measured using quantitative computed tomography (QCT) in nonhuman primates. This study aimed to describe changes in the characteristics of lumbar vBMD with age, to analyze the relationship between lumbar vBMD and body composition, and to investigate the precision of QCT measurements in healthy female cynomolgus monkeys. Age-related changes in lumbar vBMD were described using cubic regression models, and the accumulated bone loss rates (ABLR) of the lumbar spine were calculated. Spearman rank correlation and ridge regression analysis were used to investigate the relationship of the average lumbar vBMD and body components. Thirty animals were selected to analyze the short-term in vivo precision of the QCT measurements. The precision was expressed as the root-mean-square coefficient of variation (RMS-CV%) or root-mean-square standard deviation (RMS-SD). A total of 72 healthy female cynomolgus monkeys, aged 1-25 years, were included in this study. The average lumbar vBMD of female cynomolgus monkeys increased with age until the age of 10 years, around which it reached peak bone mass, with a relatively marked decline after the age of 13 years. The ABLRs of female cynomolgus monkeys in the premenopausal (13-19 years) and postmenopausal age groups (20-25 years) were -4.9% and -21.2%, respectively. Ridge regression analysis showed that age and subcutaneous adipose tissue (SAT) contributed positively to the average lumbar vBMD in animals aged ≤10 years, whereas in animals aged >10 years, age contributed negatively to lumbar vBMD. The RMS-CV% (RMS-SD) of the lumbar vBMD measured using QCT ranged from 0.47% to 1.60% (1.91-6.31 mg/cm3). Age-related changes in lumbar vBMD measured using QCT in healthy female monkeys showed similar trends to those in humans. Age and SAT may affect the lumbar vBMD in female cynomolgus monkeys. QCT revealed good precision in measuring the lumbar vBMD in female cynomolgus monkeys.

Implant-Supported Single Crowns with Titanium or Zirconia Abutments: A Retrospective Up-to-5-year Follow-up Study.

To compare the clinical outcomes of single implants with titanium (Ti) or zirconia (Zr) abutments after up to 5 years in function. This study was a retrospective analysis on single implants with screw-retained abutments (Zr or Ti) covered with porcelain veneer placed between 2011 and 2013 at one referral specialist clinic. Clinical data from patient records were collected from 132 patients and 174 implants. Technical complications such as fractures, chipping, and abutment screw loosening were registered. Radiographs were analyzed comparing both annual bone loss and accumulated bone loss at 5 years. In 57 patients with 85 implants, the values of accumulated bone loss at 5 years were compared to baseline. Technical complications occurred in 16 (9%) of the implants, most often during the first year. The following complications were found: fracture of the abutment (n = 1); loosening of the abutment screws (n = 5); and chipping of the porcelain veneer (n = 11). Ti abutments had more complications than Zr abutments (79%). Of all the implants, 45% had an annual bone loss ranging between 0.05 and 2.15 mm, and 59% had an accumulated bone loss at 5 years ranging between 0.05 and 4.25 mm. Zr abutments had a statistically significantly higher amount of yearly and accumulated bone loss at 5 years. Abutment material affected marginal bone loss. The Zr group displayed statistically more bone loss both yearly and after 5 years compared to the Ti group. Technical complications were not affected by abutment material but were affected by age of the patient.

One Abutment One Time: A Multicenter, Prospective, Controlled, Randomized Study.

Aim: (PRIMARY) Assess the changes in bone level (6 and 12 months after implant placement) between the test (definitive abutment (DEF)) and control (healing abutment (HEA)) groups. (SECONDARY) Assess the changes in bone level (6 and 12 months after implant placement) between the 1 mm high abutment group and 2 mm abutment group. Evaluate changes in implant stability recorded with analysis of the resonance frequency (RFA) Osstell system, at 6 and 12 months after implant placement, between the control group (HEA) and test (DEF). For the DEF group, the abutment was placed at the time of the surgery and was never removed. For the HEA group, the abutment was removed three times during the manufacture of the crowns. The abutments used were 1 mm high (Subgroup A) and 2 mm high (Subgroup B). Materials and methods: A total of 147 patients were selected between 54.82 ± 11.92 years old. After implant placement, patients were randomly distributed in the DEF and HEA group. After the implant placement, a periapical radiograph was taken to assess the peri-implant bone level; the same procedure was carried out 6 and 12 months post-placement. To compare the qualitative variables between the groups (HEA/DEF), the Chi-square test was used; for quantitative (MANOVA). Results: After a year, the accumulated bone loss was 0.48 ± 0.71 mm for the HEA group and 0.36 ± 0.79 mm for the DEF group, without statistical significance. Differences were only found due to timing (time) between 0 and 6 months (=0.001) and 0 and 12 months (0.001), with no differences attributable to the study groups (DEF and HEA). The accumulated bone loss (1 year) was 0.45 ± 0.78 mm for the 1 mm abutment group and 0.41 ± 0.70 mm for the 2 mm abutment group (p = 0.02). No differences were observed in implant stability between groups. Conclusions: The “One Abutment—One Time” concept does not reduce peri-implant bone loss compared to the connection–disconnection technique. The height of the abutment does influence bone loss: the higher the abutment, the lower the bone loss.

한국 남성의 연령에 따른 부위별 골밀도 변화 및 골 소실률

국민건강영양조사 제 5기 1 2차년도에 참여한 남성을 대상으로 연령에 따른 부위별 골밀도 변화, 골 소실률에 대해서 알아보고자 시도 하였다. 연령에 따른 골밀도 변화를 가장 잘 보여 주기 위해 Cubic regression을 사용하였고, 척추, 대퇴경부, 대퇴골 전자부, Ward 부위 골밀도 차이는 분산분석을 이용하여 분석하였다. 연구결과, 요추, 대퇴골 전체, 대퇴경부, 대퇴골 전자부, Ward 부위의 최대 골밀도는 20-24세였으며, 75-79세에서 골 소실률이 가장 높았다. 따라서, 남성에서는 75세 이상에서 골다공증의 집중적인 관리가 필요할 것이며, 남성에서의 골다공증 진단기준은 국제 임상 골밀도 학회(The International Society for Clinical Densitometry; ISCD)의 지침을 따르는 방안을 고려해 봐야 할 것이다. This study examined the age-related bone mineral density (BMD), accumulated bone loss rate (ABLR) at different skeletal sites in Korean men using the data from the Korea National Health and Nutrition Examination Survey (KNHANES)(the 1st (2010), 2nd (2010) and the year at the 5th survey). The cubic regression model was found to be the best for describing the age-related changes in BMD. The lumbar spine, total hip, femoral neck, trochanter, Ward's triangle in the bone mineral density difference were analyzed by ANOVA. The peak BMD was at 20-24 years at the lumbar spine, total hip, femoral neck, trochanter, Ward's triangle, and the 75-79 years of age group had the highest Accumulated Bone Loss Rate. Therefore, intensive management will be necessary for men over 75 years, and a diagnosis of osteoporosis in Korean men should be made according to The International Society for Clinical Densitometry; ISCD.

Early Laser‐Welded Titanium Frameworks Supported by Implants in the Edentulous Mandible: A 15‐Year Comparative Follow‐Up Study

Comparative long-term knowledge of different framework materials in the edentulous implant patient is not available for 15 years of follow-up. To report and compare a 15-year retrospective data on implant-supported prostheses in the edentulous mandible provided with laser-welded titanium frameworks (test) and gold alloy frameworks (control). Altogether, 155 patients were consecutively treated with abutment-level prostheses with two early generations of fixed laser-welded titanium frameworks (titanium group). Fifty-three selected patients with gold alloy castings formed the control group. Clinical and radiographic 15-year data were collected and compared for the groups. All patients who were followed up for 15 years (n = 72) still had a fixed prosthesis in the mandible at the termination of the study. The 15-year original prosthesis cumulative survival rate (CSR) was 89.2 and 100% for titanium and control frameworks (p = .057), respectively (overall CSR 91.7%). The overall 15-year implant CSR was 98.7%. The average 15-year bone loss was 0.59 mm (SD 0.56) and 0.98 mm (SD 0.64) for the test and control groups (p = .027), respectively. Few (1.3%) implants had >3.1-mm accumulated bone loss after 15 years. The most common complications for titanium frameworks were resin or veneer fractures and soft tissue inflammation. Fractures of the titanium metal frame were observed in 15.5% of the patients. More patients had framework fractures in the earliest titanium group (Ti-1 group) compared to the gold alloy group (p = .034). Loose and fractured implant screw components were few (2.4%). Predictable overall long-term results could be maintained with the present treatment modality. Fractures of the metal frames and remade prostheses were more common in the test group, and the gold alloy frameworks had a tendency to work better when compared with welded titanium frameworks during 15 years. However, on the average, more bone loss was observed for implants supporting gold alloy frameworks.

Laser‐Welded Titanium Frameworks Supported by Implants in the Partially Edentulous Mandible: A 10‐Year Comparative Follow‐Up Study

Comparative long-term knowledge of different framework materials in the partially edentulous implant patient is not available. To report and compare 10-year data on free-standing implant-supported partial prostheses with laser-welded titanium (test) and conventional gold alloy (control) frameworks. Altogether, 52 partially edentulous patients were consecutively provided with laser-welded prostheses (n = 60) in the partially edentulous lower jaw (test group). A control group of 52 randomly selected patients with gold alloy castings (n = 60) was used for comparison. Clinical and radiographic 10-year data were retrospectively collected and evaluated for both groups. The overall 10-year implant cumulative survival rate (CSR) was 93.0% (loaded implants, 96.4%), with a 10-year implant CSR of 91.5 and 94.7% for test and control implants, respectively (p > .05). Out of a total of 22 lost implants, 17 implants (77.3%) were shorter than 10 mm. The overall 10-year prosthesis CSR was 93.7%, with a corresponding 10-year CSR of 88.4 and 100% for test and control groups, respectively (p < .05). Average 10-year bone loss was 0.46 mm (SD 0.47) and 0.69 mm (SD 0.53) for the test and control groups (p < .001), respectively. Only 1% of the implants had >3 mm accumulated bone loss after 10 years. Altogether, 10 of the prostheses in both groups had implant component mechanical problems (8.3%). None of the frameworks or implants fractured, but more fractures of porcelain veneers were observed in the test group (p < .05). The protocol of implant treatment in the partially edentulous jaw functioned well during 10 years, although prosthodontic maintenance was required. However, laser-welded titanium frameworks presented more problems as compared with gold alloy frameworks. More loaded implants were lost (p < .05), and higher incidence of porcelain chipping was noted in the test group (p < .05). However, bone loss was on an average lower for the test group during the 10 years of follow-up (p < .001).

Differences in age-related bone mass of proximal femur between Chinese women and different ethnic women in the United States

Substantial racial differences in bone mass and bone loss rate have been reported, but the extent of the difference between native Chinese women and women of different races in the United States is not clear. We used a DXA bone densitometer to measure bone mineral density (BMD), bone mineral content (BMC), bone area (BA), and volumetric BMD (vBMD) in different regions of the proximal femur in 3614 Chinese women aged 20 years and older. Regression models were chosen to best fit the changes of these parameters with increasing age. The values in their fitted curves were determined by the Cartesian coordinate numeration system. Subsequently, we compared these fitted curves to full-matched data of non-Hispanic black, non-Hispanic white, and Mexican American women reported by the third National Health and Nutrition Examination Survey (NHANES III). We found that all fitted curves of bone mass of non-Hispanic black women were significantly higher than those of Chinese, non-Hispanic white, and Mexican American women (P = 0.000). The BMD and BMC fitted curves in various regions of the hip for non-Hispanic blacks were 22%-28% and 26%-43% higher than those for Chinese women, 8.3%-13% and 7.9%-9.5% higher than those for non-Hispanic whites, and 8.8%-10% and 13%-19% higher than those for Mexican Americans, respectively. However, when the expression of difference was transformed from BMD to vBMD at the femoral neck, the difference between Chinese and non-Hispanic black women was reduced from 22% to 18% and that between Chinese and non-Hispanic white women from 7.4% to 0.8%, but the difference increased from 3.2% to 9.6% between non-Hispanic white and Mexican American women and from 13% to 17% between non-Hispanic white and non-Hispanic black women. By the age of 80 years, the accumulated bone loss rate in various regions of the proximal femur for Chinese, Mexican Americans, non-Hispanic whites, and non-Hispanic blacks were -38.9% +/- 1.8%, -34.4% +/- 3.1%, -27.8% +/- 5.9%, and -28.4% +/- 4.8%, respectively. In conclusion, bone mass in the proximal femur of native Chinese women is significantly lower, and the bone loss rate greater, than those of non-Asian women in the United States. At the femoral neck, the vBMD of Chinese women is similar to that of non-Hispanic white women.

Implant Treatment in the Edentulous Maxillae: A 15‐Year Follow‐Up Study on 76 Consecutive Patients Provided with Fixed Prostheses

Few long-term follow-up studies are available on implant treatment based on patient level data related to time. The aim of this study was to report 15-year patient-based data in relation to time of follow up after treatment with fixed prostheses supported by implants in the edentulous upper jaw. Seventy-six edentulous consecutive patients, provided with 450 turned Brånemark implants, were followed up with regard to maintenance, complications, and radiographs taken during the follow-up period. Forty-four patients provided with 247 implants were lost to follow up. Patients followed up for 15 years showed as a group a trend of better implant survival than patients lost to follow up (p > .05). Altogether, 37 implants and 5 fixed prostheses failed during the follow-up period. Most implants were lost at abutment surgery (n- 15) and another nine during the first year of function. The 15-year implant and fixed prosthesis cumulative survival rate was 90.9 and 90.6%, respectively. Resin veneer fractures caused most problems, more frequent in the earlier stage while severe wear increased in the later stage of follow up. No implant fractures or loosening of abutment/bridge locking screws were noted. The mean marginal bone loss was 0.5 mm (SD 0.47) after 5 years, followed by only minimal average changes during the following years. No radiographic parameter showed any time-dependent relationship. The percentage of patients presenting at least one implant with more than 2.0-mm bone loss was 4.9% in the interval from 0 to 5 years and 4.0% between 10 and 15 years. Only 1.3% of implants showed >3.0 mm accumulated bone loss after 15 years. Implant treatment in the edentulous upper jaw functions well in a 15-year time perspective, but an insignificant trend of higher implant failures was observed for patients lost to follow up. Besides wear and fractures of veneers, no other parameter showed any time-related relationship, indicating an increased risk for more complications during later stages of follow up. However, accumulation of smaller amount of bone loss during the years resulted in an increasing number of implants and patients with bone levels below the third thread, which could be speculated to increase future maintenance after 15 years.

Age-related bone mineral density, accumulated bone loss rate and prevalence of osteoporosis at multiple skeletal sites in chinese women.

We investigated the age-related bone mineral density (BMD), accumulated bone loss rate (ABLR) and the prevalence of osteoporosis at different skeletal sites in Chinese women. BMD was measured at the anteroposterior (AP) spine, supine lateral spine (areal BMD at the midarea [mLat] and the whole region [Lat], volumetric BMD at the middle region [MVD] and total region [TVD]), hip (femoral neck [FN], trochanter [Troc] and Ward's triangle [Ward's]) and forearm (radius + ulna ultradistal [RUUD], 1/3 region [RU1/3] and total region [RUT]) using a dual-energy X-ray absorptiometry (DXA) fan-beam bone densitometer (Hologic QDR 4500A) in 2702 females aged from 5 to 96 years old. Data were analyzed by eight different regression models. We found that the cubic regression model was the best for describing age-related changes in BMD. The coefficients of determination ( R(2)) of the fitting curve were 0.398 to 0.612 ( p = 0.000). The data were then analyzed by 5-year age groups. This showed that the earliest peak BMD was at the age of 20-24 years at Troc and Ward's, and the latest at the age of 40-44 years at RU1/3 and RUT of the distal forearm. Compared with BMD, the ABLRs were highest at Ward's (-66.2%) and the lowest at RU1/3 of the distal forearm (-31.3%) in subjects over 80 years old. The prevalence of osteoporosis at at least one site in these women was 0.5 +/- 0.4% in those 30-39, 4.6 +/- 4.4% in those 40-49, 23.9 +/- 13.3% in those 50-59, 56.3 +/- 20.3% in those 60-69, 71.8 +/- 16.7% in those 70-79 and 83.2 +/- 12.1% those over 80 years of age, respectively. The prevalence of osteoporosis in these women was 8.6-11.1% at the age of 40-49 and 36.5-40.6% at the age of 50-59 at the lateral spine regions (mLat, Lat, MVD and TVD), and 0.5-3.7% at the age of 40-49 and and 3.9-21.7% at the age of 50-59 years at the other skeletal sites (AP, FN, Troc, Ward's, RUUD, RU1/3 and RUT). Significant differences were found in the prevalence of osteoporosis between the lateral spine regions and other skeletal sites ( p<0.001) at the age of 40-59 years. In summary, we demonstrated significant age-related differences in peak BMD, ABLR and osteoporosis prevalence among various skeletal sites. Our data suggest that the supine lateral spine is the most sensitive site for the diagnosis of osteoporosis, especially in the early menopausal period, although the prevalence of osteoporosis varied with age and with different sites measured.