Bone stability around implants in elderly patients with reduced bone mineral density - a prospective study on mandibular overdentures.

OBJECTIVE: The purpose of this prospective clinical study was to determine whether reduced bone mineral density (BMD) is correlated with a higher risk for dental implant therapy in an elderly patient population. MATERIAL AND METHODS: Seventy-nine patients recruited at the Prince Philip Dental Hospital were provided with 2-implant-supported mandibular overdentures. Skeletal BMD was recorded before the implant therapy. The World Health Organization Osteoporosis Diagnosis Classification (femoral neck score) was utilized to define the osteoporosis status of patients. Periapical radiographs were taken with a special radiographic holder at the time of implant loading (baseline) and at follow-up examinations. The mesial and distal marginal bone levels of each implant were measured. The mean marginal bone loss (mMBL) and greatest marginal bone loss (GBL) of four implant sites at patient level were recorded for data analysis. Clinical examination including plaque score (PI) and bleeding on probing (BOP) was recorded. RESULTS: Of the 79 patients recruited in the study, the survival rate of implant was 98.7%. Sixty-three patients (79.7%) were finally available for data collection and statistical analyses. The mean follow-up time was 62.9 (SD = 15.2) months with the mean MBL 0.65 mm (SD = 0.67) and mean GBL 1.25 mm (SD = 0.83), respectively. The average BOP and PI of patients were 49.6% (SD = 30.8) and 47.4% (SD = 37.4). Only BOP was found significantly correlated with mMBL (r = 0.321, P = 0.01). Skeletal BMD was not associated with marginal bone loss (mean MBL: r = -0.094, P = 0.466; mean GBL: r = 0.04, P = 0.761). CONCLUSIONS: Within the limits of this study, osteoporosis was not a contraindication for implant therapy, and reduced skeletal BMD was not associated with increased marginal bone loss around implants or other complications in an elderly population.

Ceramic dental biomaterials and CAD/CAM technology: state of the art.

PURPOSE: Ceramics are widely used as indirect restorative materials in dentistry because of their high biocompatibility and pleasing aesthetics. The objective is to review the state of the arts of CAD/CAM all-ceramic biomaterials. STUDY SELECTION: CAD/CAM all-ceramic biomaterials are highlighted and a subsequent literature search was conducted for the relevant subjects using PubMed followed by manual search. RESULTS: Developments in CAD/CAM technology have catalyzed researches in all-ceramic biomaterials and their applications. Feldspathic glass ceramic and glass infiltrated ceramic can be fabricated by traditional laboratory methods or CAD/CAM. The advent of polycrystalline ceramics is a direct result of CAD/CAM technology without which the fabrication would not have been possible. CONCLUSIONS: The clinical uses of these ceramics have met with variable clinical success. Multiple options are now available to the clinicians for the fabrication of aesthetic all ceramic restorations.

Prosthetic outcome, patient complaints, and nutritional effects on elderly patients with magnet-retained, implant-supported overdentures--a 1-year report.

PURPOSE: To study the changes in treatment outcomes of complete dentures and magnet-retained, implant-supported overdentures in a group of elderly patients. MATERIALS AND METHODS: In this nonrandomized trial, 43 edentulous patients (14 men and 29 women) were fitted with complete dentures followed by implant-supported mandibular overdenture in a sequential model. Treatment outcomes used for analysis included objective assessment of denture quality (Woelfel's index), patient satisfaction, nutritional status, body mass index (BMI), and serum albumin level. The McNemar test was used to determine if significant differences in the Woelfel's index and nutritional status existed at different treatment phases. Repeated measures ANOVA and multiple pairwise comparison tests were used to analyze patient satisfaction. BMI status and serum albumin level at different treatment phases were analyzed with one-way ANOVA and Tukey post hoc test. RESULTS: At the 1-year follow-up, significant improvements were recorded for the objective assessment of denture quality and patient complaints (P < .05). No subject was found to be malnourished at pretreatment and in subsequent treatment phases. BMI and serum albumin level were not significantly different at different treatment phases (P > .05) CONCLUSIONS: The present study demonstrated that in elderly patients with stable health and nutritional status, complete dentures made in a university clinic brought about overall improvement in denture quality and reduction in denture complaint score. Insertion of mandibular implant-supported overdentures further improved the mandibular denture quality and reduced the mandibular denture complaint score. In this group of patients, no improvement in BMI, serum albumin value, and nutritional status were documented.

Stereoscopic technique for conversion of radiographic guide into implant surgical guide.

PURPOSE: The aim of this study was to develop and evaluate a new stereoscopic technique for conversion of radiographic guide into surgical guide for dental implant placement. MATERIALS AND METHODS: Ten partially dentate patients requiring 18 implants for tooth replacement were recruited. Radiographic guides were modified with the addition of index rods for double computed tomography scanning. Implant positions were planned with implant planning software, and the stereoscopic angulations were measured. The radiographic guides were converted into surgical guides using either a generic bench drill (Group A, n = 9) or a milling machine (Group B, n = 9). Stereolithographic surgical guides were also made for three patients (Group S, n = 5). Differences between the planned and actual angulations were tested by pair-sample t-test. Difference of mean angle deviation among groups was tested by Brown-Forsythe test. Differences were considered significant if p < .05. RESULTS: Eighteen implant sites were successfully treated with the converted surgical guides. The mean angle deviation of Group A (1.3 ± 0.6°) was significantly greater than Group S (0.4 ± 0.6°), while no differences were found between Group B (0.9 ± 0.3°) and Group S. The linear error was greatest in Group A with 1.5 mm at the head and 1.8 mm at the apex of the implant. CONCLUSIONS: The use of this new stereoscopic technique appears to be an acceptable alternative method for converting radiographic guide into surgical guide.

Dental implant practice among Hong Kong general dental practitioners in 2004 and 2008.

OBJECTIVE: To describe the dental implant practice profile of Hong Kong general dental practitioners in 2008 and the trend since 2004. MATERIALS AND METHODS: A self-administered questionnaire was mailed to 630 dentists through systematic sampling of registered dentists. RESULTS: A total of 290 completed questionnaires were returned (response rate, 53%). Implant dentistry was practiced by 61% of the respondents. The survey also revealed that 84% of those respondents who own their private practice performed implant dentistry. About half of the dentists (49%) who performed implant dentistry placed or restored 5 or more implants per quarter. Among those dentists not practicing implant dentistry, the majority (85%) were interested in attending continuing education courses in dental implantology. CONCLUSION: There has been a significant increase in the number of general dental practitioners practicing implant dentistry in Hong Kong since 2004. By 2008, more than half of the general dental practitioners (61%) are practicing implant dentistry. Most of them not practicing implant dentistry expressed a desire to learn more about dental implants. This survey revealed a high demand for continuing professional development in implant dentistry in Hong Kong.