The effect of bone particle size on the histomorphometric and clinical outcomes following lateral ridge augmentation procedures: A randomized double-blinded controlled trial.

BACKGROUND: The aim of this randomized clinical trial was to clinically and histologically compare the amount and quality of bone gained after lateral ridge augmentation (LRA) procedures performed using small-particle (SP)-size (250-1000 µm) versus large-particle (LP)-size (1000-2000 µm) size corticocancellous bone allografts at 6 months following surgical intervention. METHODS: Twenty-two patients, each presenting with ridge width <5 mm were enrolled. Patients were randomly allocated to SP- and LP-size graft. The gain in ridge width at the level of the crest and 4 mm apical to the crest was assessed via a standardized procedure before grafting and at time of implant placement, using a surgical caliper and a novel digital technique using cone-beam computed tomography (CBCT). Six months following the procedure, trephine bone cores were taken from 19 augmented sites of 17 patients (14/19 sites were in the posterior mandible) who completed the study for clinical, histologic, and histomorphometric analysis. RESULTS: Seventeen patients (19 sites) completed the study. An LP-size graft resulted in greater ridge width gain at the level of the crest (LP 5.1 ± 1.7; SP 3.7 ± 1.3 mm; p = 0.0642) and 4 mm apical to the crest (LP 5.9 ± 2.2; SP 5.1 ± 1.8 mm; p = 0.4480) compared with the SP. No statistical significance for the bone density at the time of implant placement (p = 1.00) was found. Vital bone formation was more extensive in the SP compared with the LP (41.0 ± 10.1% vs. 31.4 ± 14.8%, respectively; p = 0.05). CONCLUSION: The results of the present study show a trend of higher ridge gain using LP during the bone augmentation procedure. Future research with bigger sample size should confirm the results of the present research.

Efficacy of micronized acellular dermal graft for use in interproximal papillae regeneration.

The aim of this study was to evaluate interdental papillary reconstruction based on a micronized acellular dermal matrix allograft technique. Thirty-eight papillae in 12 patients with esthetic complaints of insufficient papillae were evaluated. Decreased gingival recession values were found postoperatively (P < .001). Chi-square analysis showed significantly higher postoperative Papilla Index values (chi-square = 43, P < .001), further supported by positive symmetry statistical analysis values (positive kappa and weighted kappa values). This procedure shows promise as a method for papillary reconstruction.

Periodontal health of older men: the MrOS dental study.

OBJECTIVE: The purpose of this study was to evaluate the prevalence and severity of periodontitis in men of 65+ years and identify demographic and lifestyle factors associated with its presence. METHODS: Participants were recruited from the Osteoporotic Fractures in Men Study, a longitudinal study of risk factors for fractures in older men. Dental measures included clinical attachment loss (CAL), pocket depth (PD), calculus, plaque and bleeding on a random half-mouth, plus a questionnaire regarding access to care, symptoms and previous diagnosis. RESULTS: 1210 dentate men completed the dental visit. Average age was 75 years, 39% reported some graduate school education, 32% smoked 20 + pack years and 88% reported their overall health as excellent/good. In terms of periodontal health, 38% had sub-gingival calculus, 53% gingival bleeding, 82% CAL > or =5 mm and 34% PD > or =6 mm. The prevalence of severe periodontitis was 38%. Significant demographic and lifestyle factors associated with severe periodontitis in multivariate analyses included age > or =75 (OR 1.4, 95% CI 1.1-1.7) non-white race (OR 1.9, 95% CI 1.3-2.8), less than an annual dental visit (OR 1.5, 95% CI 1.1-2.0), and 20 + pack years (OR 2.1, 95% CI 1.6-2.7). CONCLUSION: A high proportion of healthy older men have evidence of periodontal destruction which could, given the growing ageing population, have a significant impact on the dental profession's ability to provide preventive and therapeutic care. The population at highest risk of periodontitis in MrOS is older minority men who smoke and do not have annual dental visits.

A prospective, randomized, controlled comparison of platform-switched and matched-abutment implants in short-span partial denture situations.

Recent observations suggest that less bone loss may result from placing a more medialized abutment on an implant (platform switching). The objective of this study was to measure the radiographic crestal bone loss and biologic width around conventional and platform-switched implants. Implants were randomly assigned into conventional or switched categories within the same prosthesis. Twenty-five implants were placed and observed in the mandibles of 10 patients for 2 years. A regression analysis demonstrated a significant difference between groups (P < or = .0001). These findings suggest that less crestal bone loss occurs around a platform-switched dental implant versus a conventional implant.

Initial clinical efficacy of 3-mm implants immediately placed into function in conditions of limited spacing.

PURPOSE: The objective of this study was to determine changes in interdental papillae, alveolar bone loss, esthetics, and initial healing survival when 1-piece narrow-diameter implants were immediately loaded in sites with limited tooth-to-tooth spacing. MATERIALS AND METHODS: One-piece titanium alloy implants with a maximum diameter of 3.0 mm and a resorbable blast surface texture on a square-thread form were evaluated. Digital photographs were made at each clinical visit to assess soft tissue healing. Interproximal soft tissue fill of the embrasure was assessed with a modified Jemt index. Standardized radiographs were made at baseline (implant placement) and at 6 and 12 months postsurgery. Radiographic bone height was measured from a consistent landmark on the implant. A 1-sided t test was used to determine statistical differences of bone height. RESULTS: Thirty-one implants were placed in 17 subjects. One implant had clinical mobility and was removed, for an overall survival rate of 96.7%. Mean bone height on the day of placement and restoration was 2.33 + 0.73 mm above the first thread. Mean bone height was 1.75 +/- 0.78 mm at 6 months postrestoration and 1.63 +/- 0.81 mm at 12 months postrestoration. There was a statistically significant loss of bone support over the initial 6 months (0.58 mm; P < .01), with no significant progression thereafter (0.12 mm; NS). Complete fill of papillae was found in 92% of maxillary lateral incisor sites and 60% of mandibular incisor sites. CONCLUSION: The use of 1-piece narrow-diameter immediately loaded implants appears to be an effective prosthetic treatment for areas of limited space.

Periodontal disease and preterm birth: results of a pilot intervention study.

BACKGROUND: Previous case-control and prospective studies have shown an association between the presence of periodontitis and the risk of preterm birth (PTB). The goal of this pilot trial was to determine the feasibility of conducting a trial to determine whether treatment of periodontitis reduces the risk of spontaneous preterm birth (SPTB). METHODS: Three hundred sixty-six (366) women with periodontitis between 21 and 25 weeks' gestation were recruited and randomized to one of three treatment groups with stratification on the following two factors: 1) previous SPTB at <35 weeks and 2) body mass index <19.8 or bacterial vaginosis as assessed by Gram stain. The treatment groups consisted of: 1) dental prophylaxis plus placebo capsule; 2) scaling and root planing (SRP) plus placebo capsule; and 3) SRP plus metronidazole capsule (250 mg t.i.d. for one week). An additional group of 723 pregnant women meeting the same criteria for periodontitis and enrolled in a prospective study served as an untreated reference group. RESULTS: The rate of PTB at <35 weeks was 4.9% in the prophylaxis group, compared to 3.3% in the SRP plus metronidazole group and 0.8% in the SRP plus placebo group (P = 0.75 and 0.12, respectively). The rate of PTB at <35 weeks was 6.3% in the reference group. CONCLUSIONS: This trial indicates that performing SRP in pregnant women with periodontitis may reduce PTB in this population. Adjunctive metronidazole therapy did not improve pregnancy outcome. Larger trials will be needed to achieve statistical significance, especially at less than 35 weeks gestational age.

A comparison of hydroxyapatite (HA) -coated threaded, HA-coated cylindric, and titanium threaded endosseous dental implants.

PURPOSE: The purpose of this study was to compare the success of hydroxyapatite (HA) -coated and machined titanium (Ti) implants in a 5-year randomized, controlled clinical trial conducted at 2 centers. MATERIALS AND METHODS: Each of 120 edentulous patients received HA-coated threaded, HA-coated cylindric, and machined Ti threaded implants in a randomized design using 5 or 6 implants. Digital radiographs allowed for yearly measurements of bone loss. Calibrated clinicians also measured mobility, Gingival Index, Plaque Index, probing depth, and recession. A Kaplan-Meier analysis was used to compare the proportion of ailing implants (defined as less than 2 mm of alveolar bone loss over 5 years) for each type of implant design. The criteria employed to assess implant outcome included the need for successful implants to lose less than 2 mm of bone support over the 5 years following placement of the prosthesis. RESULTS: This analysis revealed that 95.2% of machined Ti threaded implants and 97.92% of HA-coated threaded implants were successful, while 99.0% of HA-coated cylindric implants experienced less than 2 mm of bone loss (P < .06). DISCUSSION: All types of implants placed in this study had success rates above 95%. CONCLUSION: Over 5 years, the success rate tended to favor HA-coated implants.

Intrapocket anesthesia for scaling and root planing in pain-sensitive patients.

BACKGROUND: In 2 previous multicenter studies evaluating the efficacy of a novel anesthetic gel (lidocaine 25 mg/g plus prilocaine 25 mg/g), there was a rather small, although statistically significant, overall difference between the active and placebo gels. There were, however, large center variations. At centers where the placebo-treated patients reported high pain scores, the difference between treatments was large, suggesting that the anesthetic gel is most effective in patients who experience the procedure as painful. The present multicenter, double-blind, randomized study evaluated the anesthetic effect of this gel in pain-sensitive patients by using a visual analog scale (VAS) and a verbal rating scale (VRS). METHODS: One hundred thirteen (113) patients with moderate to severe periodontitis were screened for pain sensitivity upon probing. Eighty-five reported VAS > or = 30 mm on probing and were included in the treatment phase (43 anesthetic and 42 placebo gel). The periodontal pockets of one quadrant in each patient were treated with gel for 30 to 45 seconds, followed by scaling and/or root planing. RESULTS: The results were similar between centers. The median overall VAS pain score was 11 mm in the anesthetic group and 27 mm in the placebo group. The Hodges-Lehmann point estimate of the treatment difference was 10 mm (P = 0.004). No pain or only mild pain was reported by 70% in the anesthetic group and by 48% in the placebo group (P = 0.003). Two patients in the anesthetic group and 7 patients in the placebo group required rescue anesthesia. CONCLUSIONS: This study confirms the favorable anesthetic efficacy of active gel over placebo in selected pain-sensitive patients. It suggests that the gel may be a valuable alternative to conventional injection anesthesia.

Efficacy of controlled-release subgingival chlorhexidine to enhance periodontal regeneration.

BACKGROUND: Periodontal regeneration success may be limited by placing bone grafts and membranes in infected sites. The objective of this study was to test the hypothesis that adjunctive subgingival administration of chlorhexidine gelatin bioresorbable chips enhances bone gain when used in conjunction with guided tissue regeneration. METHODS: This was a single center, blinded, 2-arm parallel design study of 44 subjects with one or more sites with probing depth and clinical attachment loss > or = 5 mm following initial therapy and radiographic evidence of bone loss. The patients were randomly assigned to receive either chlorhexidine (CHX) chip or sham chip placement one week prior to regenerative therapy that included graft placement and site coverage with guided tissue membranes. Patients also received CHX or sham chip placement, per their randomization, adjunctively to scaling and root planing or maintenance procedures. Periodontal examinations were completed at baseline (8 weeks prior to surgery); 1 week prior to surgery; and at 3, 6, and 9 months postsurgery. The major outcomes for the study were changes in bone height and bone mass as measured from standardized radiographs used for quantitative digital subtraction radiography over the 11-month study period. RESULTS: Subjects receiving sham chip placement gained a mean bone height of 1.49 +/- 0.22 mm, while patients receiving the CHX chips gained significantly more bone height (3.54 +/- 0.45 mm; P<0.001). Similarly, subjects receiving CHX chips as an adjunct gained significantly more bone mass (5.57 +/- 0.69 mg; P<0.001) than the standard therapy (2.59 +/- 0.34 mg). CONCLUSIONS: These pilot results indicate that locally delivered, controlled-release antimicrobial treatment may improve the amount of bone gain during guided tissue regeneration procedures. These data support the evidence that infection control is an important variable in successful regeneration.

Osteoporosis and periodontal bone loss.

Osteoporosis and osteopenia are characterized by reductions in bone mass, and may lead to skeletal fragility and fracture. Until the advent and widespread use of such methodology to measure bone density, such as dual energy X-ray absorption (DXA), the definition of osteoporosis was usually made using the clinical signs of a fracture. In 1994 the World Health Organization defined osteoporosis as a bone mineral density level more than 2.5 standard deviations below the mean of young normal women (WHO, 1994). The potential inter-relationship of the two diseases will be discussed in this paper.

Periodontal host modulation with antiproteinase, anti-inflammatory, and bone-sparing agents. A systematic review.

BACKGROUND: The use of modulating agents, including inhibition of matrix metalloproteinases (MMPs) with antiproteinases, blocking production of proinflammatory cytokines and prostaglandins with anti-inflammatory drugs, and inhibiting activation of osteoclasts with bone-sparing agents, has been postulated to be of therapeutic value as an adjunctive therapy to the management of chronic periodontitis. RATIONALE: The objective of this systematic review of the literature was to assess the adjunctive efficacy of antiproteinase, anti-inflammatory, and bone-sparing host-modulating agents in the treatment of gingivitis, aggressive periodontitis, and chronic periodontitis. FOCUSED QUESTIONS: 1. In patients with periodontal diseases, what is the effect of host-modulation agents, alone or combined with conventional therapy, compared to conventional therapy alone as assessed by clinical, radiographic, adverse, and patient-centered outcomes? 2. In patients with dental implants, what is the effect of host-modulation agents on implant success assessed by clinical, radiographic, adverse, and patient-centered outcomes? SEARCH PROTOCOL: MEDLINE, Embase, and the Cochrane Library databases were searched without language restrictions through April 1, 2002 for studies that used tetracycline (TET)-related matrix metalloproteinase (MMP) inhibitors, or non-steroidal anti-inflammatory drugs (NSAIDs) and bisphosphonate anti-osteolytic agents. The investigation also included hand searching of journals and contacting authors and industry experts. INCLUSION CRITERIA: Only human studies (randomized controlled clinical trials, cohort studies, case-control studies, cross-sectional studies, and case series) were selected. Studies were on subjects with gingivitis, aggressive or chronic periodontitis, or dental implants. Interventions included TET-related MMP inhibitors, NSAIDs, or bisphosphonate anti-osteolytic agents. EXCLUSION CRITERIA: Studies that used MMP tissue inhibitors as diagnostic or prognostic indicators of periodontal disease or that evaluated short-term systemic antibodies or locally delivered levels of drugs with antiproteinase activity were excluded. DATA COLLECTION AND ANALYSIS: The primary outcomes for assessment were changes in bone or clinical attachment levels (CAL); secondary outcomes included clinical measures of plaque, gingival inflammation, probing depth (PD), and mobility. Summary data appropriate for meta-analysis were pooled using a weighted average and analyzed using a standardized difference; the results were checked with both fixed-effects and random-effects models. MAIN RESULTS: 1. A meta-analysis done on the studies reporting changes in CAL and PD following administration of sub-antimicrobial doses of doxycycline (SDD) in conjunction with scaling and root planing (SRP) in patients with periodontitis showed a statistically significant beneficial adjunctive effect. 2. There were insufficient data to provide meta-analyses on periodontal patients treated with other host-modulating agents; descriptive tables are included. 3. NSAIDS show promise in their ability to slow periodontal disease. 4. Preliminary data on bisphosphonate agents indicate there is a potential role for these agents in periodontitis management. 5. There are a very limited number of studies on host-modulating agents and dental implants and no analyses were possible. 6. Because the treatment methodologies and clinical variables differed considerably among the studies, it is difficult to summarize the information and identify a reliable total patient population. REVIEWERS' CONCLUSIONS: 1. Large multi-center trials are needed to evaluate the role of host-modulating agents in the treatment of periodontitis. 2. NSAIDS and bisphosphonate drugs may have a potential adjunctive role in periodontal therapy. 3. The adjunctive use of SDD with SRP is statistically more effective than SRP alone in reducing PD and in achieving CAL gain.

Mandibular growth following implant restoration: does Wolff's law apply to residual ridge resorption?

This study measured bone height under a fixed detachable cantilever restoration supported by five or six endosseous implants in 60 consecutively treated patients. Panoramic films were made at surgery and 1, 2, 3, and 4 years postrestoration. A computer-enhanced method was used to measure mandibular height 5, 10, 15, and 20 mm distal to the last implant, which was used as a length. standard to correct for variation in film magnification. Implant restoration resulted in a significant growth of the mandible (baseline: 7.25 +/- 0.25 mm, 4 years: 8.18 +/- 0.18 mm; P = .05). The growth in dimension appears to occur during the first year of function.

Influence of implant geometry and surface characteristics on progressive osseointegration.

PURPOSE: Although no currently available technique for the measurement of osseointegration is entirely satisfactory, 3 clinical variables can be reasonably associated with the process: probing depth, micromobility, and crestal bone height. Micromobility can be quantified to some extent with the use of the Periotest, a commercially available instrument In this investigation, the influence of surface characteristics and geometry upon Periotest value (PTV) and probing depth measurements was studied. MATERIALS AND METHODS: In a multicenter trial, 120 healthy edentulous patients received 5 or 6 implants in the anterior mandible and were followed for 3 years. A total of 634 implants were placed. Every patient received at least 1 implant of each of 3 types: threaded titanium plasma-sprayed (TPS), threaded hydroxyapatite-coated (HA), and cylindric HA-coated. A randomization schedule assured that approximately equal numbers of each type of implant were placed and that they were uniformly distributed over the arch. RESULTS: Of the 4 tested combinations of dependent and independent variables, the only statistically significant (P < .05) effect was that of coating on PTV. At 1 year after prosthetic restoration, the mean PTV for HA-coated threaded implants was -5.36 +/- 1.24, compared with -4.86 +/- 1.70 for TPS implants. This difference steadily declined in magnitude and significance, until, after 3 years, the groups were indistinguishable. DISCUSSION: This study agrees with the previous observations that HA coating tends to accelerate the initial rate of osseointegration. The absence of a difference between threaded and cylindric implants confirms that the PTV responds to micromobility near the surface, on a scale much smaller than such gross geometric features. CONCLUSION: On the basis of these results, one may conclude that HA-coated implants exhibit a more rapid decrease in micromobility than do TPS implants of identical geometry.