Co-relationships between glandular salivary flow rates and dental caries.

OBJECTIVE: This study was designed to evaluate the relationship of age, gender, ethnicity and salivary flow rates on dental caries in an adult population using data collected from the Oral Health San Antonio Longitudinal Study of Aging (OH: SALSA). BACKGROUND: Saliva is essential to maintain a healthy oral environment and diminished output can result in dental caries. Although gender and age play a role in the quantity of saliva, little is known about the interaction of age, gender and ethnicity on dental caries and salivary flow rates. MATERIALS AND METHODS: Data from the 1147 participants in the OH: SALSA were analysed. The dependent variables were the number of teeth with untreated coronal caries, number of teeth with root caries and the number of coronal and root surfaces with untreated caries. The independent variables were stimulated and unstimulated glandular salivary flow rates along with the age, sex and ethnicity (e.g. European or Mexican ancestry) of the participants. RESULTS: Coronal caries experience was greater in younger participants while root surface caries experience was greater in the older participants. Coronal caries was lower in the older age groups while the root caries experience increased. Men had a statistically significant (p < 0.02) higher experience of root caries than women. Values for unstimulated and stimulated parotid salivary flow rates showed no age difference and remained constant with age, whereas the age differences in the unstimulated and stimulated submandibular/sublingual salivary flow rates were significant. The mean number of teeth with coronal and root caries was higher in Mexican-Americans than in European-Americans. CONCLUSIONS: Over one-fourth of the adults between the ages of 60 and 79 have untreated root caries over one-third having untreated coronal caries. Lower salivary flow rates play a significant role in both the number of teeth and the number of surfaces developing caries in these adults. Women and individuals of European-American ancestry experience less caries.

Conventional SLA and chemically modified SLA implants in patients with poorly controlled type 2 diabetes mellitus--a randomized controlled trial.

OBJECTIVE: The objective of this study was to evaluate the potential for a chemically modified Sand blasted, Large grit, Acid etched (SLA) surface, compared with a conventional SLA surface, to enhance implant healing and integration in poorly controlled diabetic patients, a group previously demonstrated to have compromises and delays in implant stabilization during the metabolically active healing period following implant placement. MATERIALS AND METHODS: The study enrolled 24 patients with type 2 diabetes, baseline HbA1c levels between 7.5-11.4%, and a minimum of two posterior mandibular tooth sites at least 4 months following extraction and appropriate for implant placement. Each patient, at a randomly selected site, received an implant with the conventional SLA surface; at the second site, the patient received an implant with the chemically modified SLA (modSLA) surface. Thus, 48 study implants were placed. Implant stability was assessed using Resonance Frequency Analysis (RFA). Readings were taken from the buccal and proximal directions for each implant. Implant stability (ISQ) was assessed at the time of surgical placement (baseline) and 2, 3, 4, 6, 8, 10, 12, and 16 weeks following implant placement. RESULTS: No significant differences in implant stability were observed between conventional SLA implants and modSLA implants, and the time courses of implant stabilization following implant placement were similar for the two implant types. Baseline ISQ and minimum ISQ was slightly higher in subjects with higher HbA1c levels, but were similar during 12-16 weeks following implant placement. Forty-seven (98%) of the 48 implants were determined to be successfully osseointegrated and continued to restoration. CONCLUSION: Implant stabilization was similar for the conventional SLA and chemically modified SLA implants in type 2 diabetic patients with relatively poor glycemic control. Furthermore, this study demonstrated clinically successful implant placement even in poorly controlled diabetic patients.

Reduction of postoperative stiffness after arthroscopic rotator cuff repair: results of a customized physical therapy regimen based on risk factors for stiffness.

PURPOSE: The purpose of this study was to determine the benefits of a modified rehabilitation protocol (incorporating early closed-chain overhead stretching) in reducing the risk of postoperative stiffness after arthroscopic rotator cuff repair. METHODS: During a 17-month period, we performed primary arthroscopic rotator cuff repairs in 152 patients. After surgery, patients with risk factors identified in the previous study (calcific tendonitis, adhesive capsulitis, PASTA [partial articular surface tendon avulsion]-type rotator cuff repair, concomitant labral repair, or single-tendon cuff repair) were enrolled in a modified rehabilitation protocol that added early overhead closed-chain passive motion exercises to our standard protocol; alternatively, patients without risk factors received a standard conservative rehabilitation program. Historical controls were used and comprised patients in the senior author's practice who all received the conservative rehabilitation protocol. The prevalence of postoperative stiffness was compared between the historical cohort and current study patients by use of Fisher exact tests. RESULTS: Among the 152 patients studied, 79 were positive for at least 1 of the specified risk factors and received the modified protocol. Postoperative stiffness developed in none of the 79 patients enrolled in the modified program. This finding represented a significant improvement (Fisher exact test, P = .004) over the historical controls, in which 18 of the 231 at-risk patients had significant postoperative stiffness develop. CONCLUSIONS: In at-risk patients (with calcific tendonitis, adhesive capsulitis, PASTA repair, concomitant labral repair, and single-tendon repair), a postoperative rehabilitation regimen that incorporates early closed-chain passive overhead motion can reduce the incidence of postoperative stiffness after arthroscopic rotator cuff repair.

Principal domains of behavioral psychopathology identified by the Bipolar Inventory of Signs and Symptoms Scale (BISS).

Current symptom rating scales and diagnostic categories for bipolar disorder (BD) do not provide dimensional profiles of the types of behavior disturbed in this complex disorder. To overcome these limitations we identified the principal domains of behavioral symptomatology in bipolar individuals, including all mood states, and used a more comprehensive rating scale for BD: the Bipolar Inventory of Signs and Symptoms Scale (BISS). A total of 246 patients with BD (196 with BD type I, and 50 with BD type II) were interviewed using the BISS. Exploratory factor analysis was performed on the BISS results using the maximum likelihood factor extraction method, followed by oblique rotation of the extracted factor loadings. We determined the strength of relationships between factor scores using the Pearson correlation coefficient. The following five factors were extracted: mania, depression, irritability, anxiety and psychosis. Anxiety was significantly correlated with depression and irritability. The mania factor score was only weakly associated with the other four factors. The domains of the BISS capture both the historical categories of depression and mania, plus irritability, psychosis, and an additional principal domain, anxiety. Despite the common occurrence of anxiety in BD, it has not been identified in most prior factor analyses, in part due to limited coverage of anxiety symptoms in the source scales.

Bone changes around early loaded chemically modified sandblasted and acid-etched surfaced implants with and without a machined collar: a radiographic and resonance frequency analysis in the canine mandible.

PURPOSE: The purpose of this study was to evaluate the radiographic bone level and stability changes around early loaded chemically modified sandblasted and acid-etched implants with and without a machined collar. MATERIALS AND METHODS: Seventy-two chemically modified sandblasted and acid-etched implants 4.1 mm in diameter and 8 mm in length were placed in six dogs. Thirty-six implants had no machined collar (NMC) and 36 had a 2.8-mm machined collar (MC). Resonance frequency measurements were obtained at placement and weekly for 3 weeks. All implants were loaded 21 days after surgery. Standardized periapical radiographs were obtained at baseline, at 3 weeks, and at 3, 6, 9, and 12 months. The radiographs were randomized and digitized, and linear measurements of the distance from the first bone-to-implant contact to the shoulder of the implant were performed at the mesial and distal aspects of each implant. For statistical analysis, mixed-model repeated-measures analysis of variance was used. RESULTS: All implants achieved hard and soft tissue integration clinically and radiographically and were clinically immobile. From placement to week 3, the mean implant stability increased for MC implants by more than 5 ISQs and for NMC implants by more than 7 ISQs. Radiographically, there were significant differences between treatment groups beginning at 3 months. After 12 months of loading, the MC implants presented a mean bone loss of 1.00 mm and the NMC implants presented a mean bone gain of 0.11 mm. CONCLUSIONS: Chemically modified sandblasted and acid-etched implants without a machined collar presented bone gain, and implants with a machined collar showed bone loss after a 1 year following early (21-day) loading. The tendency toward a coronal apposition of bone observed under these conditions may be attributed to the osteoconductive properties of the chemically modified surfaces of these implants and to the absence of the machined collar.

Accuracy of preoperative magnetic resonance imaging in predicting a subscapularis tendon tear based on arthroscopy.

PURPOSE: The purpose of this study was to evaluate the diagnostic accuracy of magnetic resonance imaging (MRI) scan assessments of subscapularis tendon tears by comparing the preoperative MRI interpretations of radiologists with the actual results determined by arthroscopic evaluations of the same shoulders. METHODS: This retrospective review comprised all 120 patients who underwent primary arthroscopic rotator cuff repairs performed by the senior author during 2006. Of the 120 patients, 90 had high-field strength, conventional MRI scans performed within 190 days before their arthroscopic procedures. RESULTS: All 16 patients with preoperative MRI scans that were interpreted by the radiologists as positive for subscapularis tendon tears were confirmed to be positive by arthroscopy, resulting in perfect specificity. However, the radiologists diagnosed only 16 of 44 subscapularis tears (36%) identified by arthroscopy. This resulted in an overall sensitivity of 36%, specificity of 100%, positive predictive value of 100%, negative predictive value of 62%, and accuracy of 69%. CONCLUSIONS: Preoperative MRI scans of the shoulder do not reliably predict which rotator cuff injury patients have subscapularis tendon tears. Subscapularis tendon tears that extend at least half the cephalad-to-caudal distance are more easily detected by MRI scans, whereas smaller tears are usually missed on MRI scans. LEVEL OF EVIDENCE: Level III, development of diagnostic criteria with universally applied reference (nonconsecutive patients).

A prospective multicenter 5-year radiographic evaluation of crestal bone levels over time in 596 dental implants placed in 192 patients.

BACKGROUND: Dental implants have been used to replace missing teeth to provide function and esthetics. One goal of such restorations is to maintain host tissue around the implants. The purpose of this prospective multicenter human clinical trial was to evaluate radiographic marginal bone levels around non-submerged hollow cylindrical and solid-screw implants for 5 years after loading. METHODS: Patients older than 18 years of age with sufficient native bone to surround a dental implant without imposing on a vital structure were recruited at five sites. Solid-screw or hollow-cylinder implants with a titanium plasma-sprayed implant surface were placed in the anterior maxilla or anterior mandible and restored with fixed restorations. Baseline radiographs were taken at the time of implant placement. Subsequent radiographs were taken at the time of final prosthesis placement, at 6 months after prosthesis placement, and annually from prosthesis placement for 5 years. RESULTS: The results of 596 implants in 192 patients at five international sites revealed that clinically significant remodeling of the marginal bone occurred during the first 6 months after implant placement, with a mean (+/- SD) marginal bone loss of 2.44 +/- 1.20 mm. After that, clinically insignificant mean changes in the bone were observed. Overall, 0.22 +/- 0.42 mm of bone loss occurred between the time of prosthesis placement and 1-year postloading. Between 1-year postloading and the last 5-year recall, 0.18 +/- 0.88 mm bone loss occurred. Because 2.84 +/- 1.63 mm of bone loss occurred between implant placement and the 5-year postloading follow-up, 86% of the total mean bone loss over the course of 5 years was accounted for at the time of prosthesis placement. These same trends occurred if the data were analyzed with regard to implant design (solid screw and hollow cylinder), type of restoration (single and multiple), and length of implant (8 to 10, 12, and 14 to 16 mm). CONCLUSIONS: These data demonstrate that, in general, clinically significant marginal bone remodeling occurred between the time of implant placement and final prosthesis placement around one-stage non-submerged titanium implants with a titanium plasma-sprayed surface. Subsequent to that, bone loss observed around implants up to 5 years postloading was minimal. These results suggest that the factors that influence early healing around implants are significantly different from those that affect later marginal bone remodeling.

A biomechanical comparison of 2 techniques of footprint reconstruction for rotator cuff repair: the SwiveLock-FiberChain construct versus standard double-row repair.

PURPOSE: The purpose of this study was to compare the biomechanical fixation parameters of a standard double-row rotator cuff repair with those of a knotless footprint reconstruction using the double-row SwiveLock-FiberChain technique (Arthrex, Naples, FL). METHODS: Seven matched pairs of human cadaveric shoulders were used for testing (mean age, 48 +/- 10.3 years). A shoulder from each matched pair was randomly selected to receive a standard 4-anchor double-row repair of the supraspinatus tendon, and the contralateral shoulder received a 4-anchor double-row SwiveLock-FiberChain repair. The tendon was cycled from 10 N to 100 N at 1 Hz for 500 cycles, followed by a single-cycle pull to failure at 33 mm/s. Yield load, ultimate load, cyclic displacement, and mode of failure were recorded. RESULTS: Yield load and ultimate load were higher for the SwiveLock-FiberChain repair compared with the standard double-row repair for 6 of the 7 treatment pairs; however, 1 cadaver had a contrary outcome, so the overall mean differences in yield load and ultimate load were not significantly different from 0 by Student t test (P > .15). Furthermore, smaller differences between yield load and ultimate load for the SwiveLock-FiberChain repair in 5 of the 7 treatment pairs showed a self-reinforcing mechanism. CONCLUSIONS: Double-row footprint reconstruction with the knotless SwiveLock-FiberChain system in this study had yield loads, ultimate loads, and cyclic displacements that were statistically equivalent to those of standard double-row rotation cuff reconstructions. CLINICAL RELEVANCE: The SwiveLock-FiberChain system's combination of strength, self-reinforcement, and decreased operating time may offer advantages to the surgeon, particularly when dealing with older patients in whom poor tissue quality and total operative time are important considerations.

Incidence and treatment of postoperative stiffness following arthroscopic rotator cuff repair.

PURPOSE: The purpose of this study was to determine the incidence of clinically significant postoperative stiffness following arthroscopic rotator cuff repair. This study also sought to determine the clinical and surgical factors that were associated with higher rates of postoperative stiffness. Finally, we analyzed the result of arthroscopic lysis of adhesions and capsular release for treatment of patients who developed refractory postoperative stiffness 4 to 19 months (median, 8 months) following arthroscopic rotator cuff repair. METHODS: A retrospective review of a consecutive series of arthroscopic rotator cuff repairs was conducted. During a 3-year time period, the senior author (S.S.B.) performed 489 arthroscopic rotator cuff repairs. The operative indications, technique of the rotator cuff repair, and the rehabilitation protocol were essentially unchanged during this time period. Demographic data, comorbid medical conditions, rotator cuff tear description, technique of repair, and concomitant surgical procedures were evaluated for their effect on stiffness. All office evaluations were reviewed to determine the pre- and postoperative motion, pain scores, functional strength, and patient satisfaction. Patients who were dissatisfied because of the development of postoperative stiffness underwent secondary arthroscopic lysis of adhesions. The final result of the secondary lysis of adhesions and capsular release were analyzed. RESULTS: In total, 24 patients (4.9%) were dissatisfied with the result of their procedure because of the development of postoperative stiffness, which was more likely (P < .05) to develop in patients with Workers' Compensation insurance (8.6%), patients younger than 50 years of age (8.6%), those with a coexisting diagnosis of calcific tendonitis (16.7%) or adhesive capsulitis (15.0%) requiring additional postoperative therapy, partial articular-sided tendon avulsion (PASTA) type rotator cuff tear (13.5%), or concomitant labral repair (11.0%). Patients with concomitant coracoplasty (2.3%) or tears larger in size and/or involving more tendons were less likely (P < .05) to develop postoperative stiffness. Among 90 patients positive for selected risk factors (adhesive capsulitis, excision of calcific deposits, single-tendon repair, PASTA repair, or any labral repair without a concomitant coracoplasty), 12 (13.3%) developed postoperative stiffness (P < .001). This overall clinical risk factor combined with Workers' Compensation insurance identified 16 of the 24 cases resulting in a sensitivity of 66.7% and a specificity of 64.5%. All 24 patients who experienced postoperative stiffness elected to undergo arthroscopic lysis of adhesions and capsular release, which was performed from 4 to 19 months (median, 8 months) after the rotator cuff repair. During second-look arthroscopy, 23 patients (95.8%) were noted to have complete healing of the original pathology. Following capsular release, all 24 patients were satisfied with the overall result of their treatment. CONCLUSIONS: In a series of 489 consecutive arthroscopic rotator cuff repairs, we found that 24 patients (4.9%) developed postoperative stiffness. Risk factors for postoperative stiffness were calcific tendinitis, adhesive capsulitis, single-tendon cuff repair, PASTA repair, being under 50 years of age, and having Workers' Compensation insurance. Twenty-three of 24 patients (95.8%) showed complete healing of the rotator cuff. Arthroscopic release resulted in normal motion in all cases. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Clinical evaluation of demineralized freeze-dried bone allograft with and without enamel matrix derivative for the treatment of periodontal osseous defects in humans.

BACKGROUND: Beneficial clinical effects have been demonstrated with the addition of enamel matrix derivative (EMD) to demineralized freeze-dried bone allograft (DFDBA) compared to EMD alone. The purpose of this study was to evaluate the effectiveness of DFDBA combined with EMD compared to DFDBA alone in the treatment of intraosseous defects of chronic periodontitis. METHODS: Thirty-two patients with 41 intrabony defects > or = 3 mm were randomly assigned to one of two treatment groups. Intrabony defects were treated with DFDBA alone or in combination with EMD. Soft tissue measurements included probing depth (PD), gingival recession, and clinical attachment level (CAL). Hard tissue measurements included height of the alveolar crest, defect depth, and defect morphology. Following 6 months of healing, all measurements were repeated with the use of a surgical reentry procedure on 29 patients. Data were analyzed to determine PD reduction, CAL gain, change in recession, crestal resorption, defect fill, defect resolution, percentage of defect fill, and percentage of defect resolution. RESULTS: Analysis of soft and hard tissue measurements demonstrated a statistically significant difference from baseline within each group (P <0.001); however, there was no statistically significant difference between the groups. CONCLUSION: Both treatments were shown to be safe and effective therapy for periodontal defects; however, the addition of EMD to DFDBA provided no statistically significant improvement to the soft and hard tissue parameters measured.

The results of arthroscopic subscapularis tendon repairs.

PURPOSE: The purpose of this study was to evaluate patients after an arthroscopic subscapularis tendon repair to determine their intermediate-term results. METHODS: The records of all patients who underwent an arthroscopic rotator cuff repair by the senior author (S.S.B.) between January 1, 2000, and December 31, 2003, were reviewed. Patients were excluded from the study if their rotator cuff was repaired but there was not a subscapularis tear. Forty patients were included in this study. The median follow-up from the date of surgery to the last clinical evaluation was 5.0 years (range, 3.2 to 7.1 years). All patients had a complete history, physical examination, and plain radiographs of their shoulders. Both the modified University of California at Los Angeles (UCLA) and American Shoulder and Elbow Society (ASES) scores were calculated. RESULTS: The visual analog scale for pain (mean +/- standard deviation) improved significantly (P < .001) from 6.1 +/- 2.4 preoperatively to 0.9 +/- 1.4 at the latest clinical follow-up evaluation; similarly, the mean modified ASES score improved significantly (P < .001) from 40.5 +/- 15.7 preoperatively to 91.2 +/- 12.7, and the mean modified UCLA score improved significantly (P < .001) from 15.7 +/- 4.2 preoperatively to 31.6 +/- 4.8. According to the UCLA scoring system, there were 18 excellent, 14 good, 6 fair, and 2 poor results. Eighty-three percent of patients returned to their usual work, sport, or hobbies after the operation. CONCLUSIONS: At a median follow-up of 5 years, 80% (32 of 40) of patients had a good or excellent result after an arthroscopic subscapularis tendon repair. Eighty-eight percent of patients were satisfied with their shoulders at the latest follow-up evaluation. We conclude that the intermediate-term results show that arthroscopic subscapularis tendon repairs remain a good option for the treatment of patients with subscapularis tendon tears. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Evaluation of two different resonance frequency devices to detect implant stability: a clinical trial.

BACKGROUND: Resonance frequency analysis (RFA) provides a non-invasive assessment of implant stability. The established RFA device uses electronic technology, whereas a recently developed device uses magnetic technology. The goal of this clinical trial was to evaluate the ability of the magnetic RFA device to detect changes in stability during early healing following implant placement and to determine whether the implant stability quotient (ISQ) values obtained correlated with those made with the electronic device. METHODS: RFA assessments were performed using electronic- and magnetic-based devices on 34 non-submerged titanium dental implants in 17 patients. Each patient received two implants in the posterior maxilla or mandible. Implant stability was measured at placement and weekly until week 6, when implants received provisional crowns, and at 12 weeks, when definitive crowns were cemented. During each visit, measurements were taken three times and averaged to obtain a single representative ISQ for each device. RESULTS: At placement, the mean ISQ obtained with the electronic device was 61.9 (95% confidence interval [CI], 59.4 to 64.3); it increased to 63.2 (95% CI, 61.2 to 65.2) at 12 weeks. With the magnetic device, the mean ISQs were 70.6 (95% CI, 68.4 to 72.8) and 75.9 (95% CI, 74.2 to 77.7), respectively. Both devices indicated a pattern of decreased mean stability from 1 to 3 weeks post-placement, small fluctuations in mean ISQ from 3 to 6 weeks, and significantly increased mean stability from 6 to 12 weeks. For the complete set of implant measures across all weeks, the paired electronic and magnetic ISQ values correlated significantly (r = 0.52; P <0.001). CONCLUSIONS: This study demonstrates that changes in implant stability measured with the newer magnetic device correlate well with those found with the electronic device. Both devices confirmed the initial decreases in implant stability that occur following placement and identified an increase in stability during the first 6 weeks of functional loading.

Improving resident performance assessment data: numeric precision and narrative specificity.

PURPOSE: To evaluate the use of a systems approach for diagnosing performance assessment problems in surgery residencies, and intervene to improve the numeric precision of global rating scores and the behavioral specificity of narrative comments. METHOD: Faculty and residents at two surgery programs participated in parallel before- and-after trials. During the baseline year, quality assurance data were gathered and problems were identified. During two subsequent intervention years, an educational specialist at each program intervened with an organizational change strategy to improve information feedback loops. Three quality-assurance measures were analyzed: (1) percentage return rate of forms, (2) generalizability coefficients and 95% confidence intervals of scores, and (3) percentage of forms with behaviorally specific narrative comments. RESULTS: Median return rates of forms increased significantly from baseline to intervention Year 1 at Site A (71% to 100%) and Site B (75% to 100%), and then remained stable during Year 2. Generalizability coefficients increased between baseline and intervention Year 1 at Site A (0.65 to 0.85) and Site B (0.58 to 0.79), and then remained stable. The 95% confidence interval around resident mean scores improved at Site A from baseline to intervention Year 1 (0.78 to 0.58) and then remained stable; at Site B, it remained constant throughout (0.55 to 0.56). The median percentage of forms with behaviorally specific narrative comments at Site A increased significantly from baseline to intervention Years 1 and 2 (50%, 57%, 82%); at Site B, the percentage increased significantly in intervention Year 1, and then remained constant (50%, 60%, 67%). CONCLUSIONS: Diagnosing performance assessment system problems and improving information feedback loops improved the quality of resident performance assessment data at both programs.

Crestal bone changes around titanium implants. Part I: A retrospective radiographic evaluation in humans comparing two non-submerged implant designs with different machined collar lengths.

BACKGROUND: Experimental studies demonstrated that peri-implant crestal hard and soft tissues are significantly influenced in their apico-coronal position by the rough/smooth implant border as well as the microgap/ interface between implant and abutment/restoration. The aim of this study was to evaluate radiographically the crestal bone level changes around two types of implants, one with a 2.8 mm smooth machined coronal length and the other with 1.8 mm collar. METHODS: In 68 patients, a total of 201 non-submerged titanium implants (101 with a 1.8 mm, 100 with a 2.8 mm long smooth coronal collar) were placed with their rough/smooth implant border at the bone crest level. From the day of surgery up until 3 years after implant placement crestal bone levels were analyzed digitally using standardized radiographs. RESULTS: Bone remodeling was most pronounced during the unloaded, initial healing phase and did not significantly differ between the two types of implants over the entire observation period (P >0.20). Crestal bone loss for implants placed in patients with poor oral hygiene was significantly higher than in patients with adequate or good plaque control (P <0.005). Furthermore, a tendency for additional crestal bone loss was detected in the group of patients who had been diagnosed with aggressive periodontitis prior to implant placement (P = 0.058). In both types of implants, sand-blasted, large grit, acid-etched (SLA) surfaced implants tended to have slightly less crestal bone loss compared to titanium plasma-sprayed (TPS) surfaced implants, but the difference was not significant (P >0.30). CONCLUSION: The implant design with the shorter smooth coronal collar had no additional bone loss and may help to reduce the risk of an exposed metal implant margin in areas of esthetic concern.

Influence of the size of the microgap on crestal bone levels in non-submerged dental implants: a radiographic study in the canine mandible.

BACKGROUND: Accumulating evidence suggests that alveolar crestal bone resorption occurs as a result of the microgap that is present between the implant-abutment interface in dental implants. The objective of this longitudinal radiographic study was to determine whether the size of the interface or the microgap between the implant and abutment influences the amount of crestal bone loss in unloaded non-submerged implants. METHODS: Sixty titanium implants having sandblasted with large grit, acid-etched (SLA) endosseous surfaces were placed in edentulous mandibular areas of 5 American fox hounds. Implant groups A, B, and C had a microgap between the implant-abutment connection of <10 microm, 50 microm, or 100 microm, respectively, as did groups D, E, and F, respectively. Abutments were either welded (1 -piece) in groups A, B, and C or non-welded (2-piece screwed) in D, E, and F. All abutment interfaces were placed 1 mm above the alveolar crest. Radiographic assessment was undertaken to evaluate peri-implant crestal bone levels at baseline and at 1, 2, and 3 months after implant placement whereupon all animals were sacrificed. RESULTS: The size of the microgap at the abutment/implant interface had no significant effect upon crestal bone loss. At 1 month, most implants developed crestal bone loss compared with baseline levels. However, during this early healing period, the non-welded group (D, E, and F) showed significantly greater crestal bone loss from baseline to one month (P <0.04) and 2 months (P < 0.02) compared with the welded group (A, B, and C). No significant differences were observed between these 2 groups at 3 months (P > 0.70). CONCLUSIONS: Crestal bone loss was an early manifestation of wound healing occurring after 1 month of implant placement. However, the size of the microgap at the implant-abutment interface had no significant effect upon crestal bone resorption. Thus, 2-piece non-welded implants showed significantly greater crestal bone loss compared with 1-piece welded implants after 1 and 2 months suggesting that the stability of the implant/abutment interface may have an important early role to play in determining crestal bone levels. At 3 months, this influence followed a similar trend but was not observed to be statistically significant. This finding implies that implant configurations incorporating interfaces will be associated with biological changes regardless of interface size and that mobility between components may have an early influence on wound healing around the implant.

Biologic width around different implant-abutment interface configurations. A radiographic evaluation of the effect of horizontal offset and concave abutment profile in the canine mandible.

PURPOSE: The purpose of this experimental study was to analyze radiographically in a dog model how different implant-abutment interface configurations influence alveolar crestal bone changes. MATERIALS AND METHODS: Six different experimental implant-abutment connections were evaluated in six mixed-breed dogs. The following parameters were tested: absence of microgap, microgap proximal to bone crest, and microgap distant from bone crest. In addition, two different cervical abutment profiles, one straight and one featuring a supracrestal concavity, were evaluated. Implants were based on a cylindrical full-body screw design and made from cold-worked grade IV commercially pure titanium. The diameter (at thread tips) measured 4.1 mm, whereas the inner diameter was 3.5 mm. Standardized periapical digital radiographs were obtained for comparative analysis at baseline and at 3, 4, 5, 6, 7, 8, and 9 months after implant placement. Radiographs were randomized and calibrated for linear measurements. For statistical analysis, mixed-model repeated-measures analysis of variance was used. RESULTS: All implants integrated successfully and remained stable during the entire period of the study. Radiographically, when comparing groups with straight profiles, crestal bone remodeling in group C (one-piece design) was significantly less than in group A (matching diameters) and B (nonmatching diameters). In fact, implant group C showed the least crestal bone remodeling of all groups. When comparing groups with a concave profile but different microgap configurations, all three designs demonstrated bone loss with no significant differences among the three groups. CONCLUSION: A nonsubmerged one-piece implant design demonstrated the least amount of bone remodeling of all groups. Implant-abutment connections with a concave profile established crestal bone levels immediately apical to the concavity regardless of the microgap variable.

Influence of a machined collar on crestal bone changes around titanium implants: a histometric study in the canine mandible.

BACKGROUND: It has been shown that peri-implant crestal bone reactions are influenced by both a rough-smooth implant border in one-piece, non-submerged, as well as an interface (microgap [MG] between implant/abutment) in two-piece butt-joint, submerged and non-submerged implants being placed at different levels in relation to the crest of the bone. According to standard surgical procedures, the rough-smooth implant border for implants with a smooth collar should be aligned with the crest of the bone exhibiting a smooth collar adjacent to peri-implant soft tissues. No data, however, are available for implants exhibiting a sandblasted, large-grit and acid-etched (SLA) surface all the way to the top of a non-submerged implant. Thus, the purpose of this study is to histometrically examine crestal bone changes around machined versus SLA-surfaced implant collars in a side-by-side comparison. METHODS: A total of 60 titanium implants (30 machined collars and 30 SLA collars) were randomly placed in edentulous mandibular areas of five foxhounds forming six different subgroups (implant subgroups A to F). The implants in subgroups A to C had a machined collar (control), whereas the implants in subgroups D to F were SLA-treated all the way to the top (MG level; test). Furthermore, the MGs of the implants were placed at different levels in relation to the crest of the bone: the implants in subgroups A and E were 2 mm above the crest, in subgroups C and D 1 mm above, in subgroup B 3 mm above, and in subgroup F at the bone crest level. For all implants, abutment healing screws were connected the day of surgery. These caps were loosened and immediately retightened monthly. At 6 months, animals were sacrificed and non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels. RESULTS: For implants in subgroup A, the estimated mean crestal bone loss (± SD) was -0.52 ± 0.40 mm; in subgroup B, +0.16 ± 0.40 mm (bone gain); in subgroup C, -1.28 ± 0.21 mm; in subgroup D, -0.43 ± 0.43 mm; in subgroup E, -0.03 ± 0.48 mm; and in subgroup F, -1.11 ± 0.27 mm. Mean bone loss for subgroup A was significantly greater than for subgroup E (P = 0.034) and bone loss for subgroup C was significantly greater than for subgroup D (P <0.001). CONCLUSIONS: Choosing a completely SLA-surfaced non-submerged implant can reduce the amount of peri-implant crestal bone loss and reduce the distance from the MG to the first bone-implant contact around unloaded implants compared to implants with a machined collar. Furthermore, a slightly exposed SLA surface during implant placement does not seem to compromise the overall hard and soft tissue integration and, in some cases, results in coronal bone formation in this canine model.

A 5-year prospective multicenter study of early loaded titanium implants with a sandblasted and acid-etched surface.

PURPOSE: For dental implants to be successful, osseointegration must occur, but it is unknown how much time must pass for osseointegration to be established. Preclinical studies suggested that titanium implants with a sandblasted and acid-etched (SLA) surface were more osteoconductive and allowed more rapid osseointegration than machined or turned implant surfaces. The hypothesis of this study was that implants with an SLA surface could be loaded in half the conventional healing time of machined-surface implants and that, after loading, the implants would be successful for 5 years. MATERIALS AND METHODS: A prospective multicenter clinical study was conducted with 439 implants placed in native bone in 135 edentulous and partially edentulous patients. Abutments were attached to the implant with 35 Ncm of torque without countertorque after 6 weeks in type I to III bone and after 12 weeks in type IV bone. The patients were carefully evaluated for 5 years. RESULTS: Most implants were placed in nonsmoking, nondiabetic patients with a mean age of 55 years (range, 21 to 82 years). Eighty percent of the implants were 10 or 12 mm long, 96% had a diameter of 4.1 mm, and 78% were placed in type II or III bone. Patients maintained good oral hygiene and were satisfied with the restorations. Four implants failed, and one implant was deemed unsuccessful between surgery and the 1-year postloading visit. No implants failed or were unsuccessful in subsequent years. The cumulative survival and success rates for 385 implants in 120 patients after 5 years were 99.1% and 98.8%, respectively. CONCLUSION: Implants with an SLA surface can be restored in 6 weeks for type I to III bone and 12 weeks for type IV bone. Furthermore, they can be maintained after loading for 5 years with very high success and survival rates.

Test of variables of attention (TOVA) as a predictor of early attention complaints, an antecedent to dementia.

The goal of this study was to determine if impairments detected by the test of variables of attention (TOVA) may be used to predict early attention complaints and memory impairments accurately in a clinical setting. We performed a statistical analysis of outcomes in a patient population screened for attention deficit hyperactivity disorder or attention complaints, processing errors as measured by TOVA and the Wechsler Memory Scale (WMS-III) results. Attention deficit disorder (ADD) checklists, constructed using the Diagnostic and Statistical Manual of Mental Disorders 4th Edition criteria, which were completed by patients at PATH Medical, revealed that 72.8% of the patients had more than one attention complaint out of a total of 16 complaints, and 41.5% had more than five complaints. For the 128 males with a significant number of ADD complaints, individuals whose scores were significantly deviant or borderline (SDB) on TOVA, had a significantly greater number of attention complaints compared with normals for omissions (P < 0.02), response time (P < 0.015), and variability (P < 0.005), but not commissions (P > 0.50). For males, the mean scores for auditory, visual, immediate, and working memory scores as measured by the WMS-III were significantly greater for normals versus SDBs on the TOVA subtest, ie, omission (P < 0.01) and response time (P < 0.05), but not variability or commissions. The means for auditory, visual, and immediate memory scores were significantly greater for normals versus SDBs for variability (P < 0.045) only. In females, the mean scores for visual and working memory scores were significantly greater for normals versus SDBs for omissions (P < 0.025). The number of SDB TOVA quarters was a significant predictor for "impaired" or "normal" group membership for visual memory (P < 0.015), but not for the other three WMS-III components. For males, the partial correlation between the number of attention complaints and the number of SDB TOVA quarters was also significant (r = 0.251, P < 0.005). For the 152 females with a significant number of attention complaints, no significant differences between SDBs and normals were observed (P > 0.15). This is the first report, to our knowledge, which provides evidence that TOVA is an accurate predictor of early attention complaints and memory impairments in a clinical setting. This finding is more robust for males than for females between the ages of 40 and 90 years.

Percutaneous radiofrequency ablation of hepatic tumors: postablation syndrome.

OBJECTIVE: Our objective was to define the spectrum and possible predictors of symptoms that occur in patients after percutaneous radiofrequency ablation of hepatic tumors. SUBJECTS AND METHODS: We performed 50 consecutive percutaneous radiofrequency ablation sessions on 39 patients with a total of 89 liver tumors. All patients had pre- and postablation laboratory studies and CT or MRI scans. After treatment, patients were followed for 3 weeks with a standardized questionnaire to assess for postablation symptoms. Comparisons of the presence or absence of symptoms were made for the laboratory test values, liver volumes, and pre- and postablation tumor volumes. RESULTS: Postablation symptoms occurred in 14 of 39 (36%) patients after 17 of 50 (34%) ablation sessions. Symptoms consisted of fever (16/17), malaise (12/17), chills (6/17), delayed pain (5/17), and nausea (2/17). On average, the symptoms presented 3 days after ablation and lasted 5 days. Statistically significant (p < 0.01) predictors of symptoms were tumor volumes > 50 cm3 (4.5 cm diameter), ablated tissue volumes > 150 cm3 (6.5 cm diameter), a difference between preablation tumor volume and the volume of tissue ablated > 125 cm3, or postablation aspartate aminotransferase levels > 350 IU/L. CONCLUSION: Approximately one third of patients undergoing percutaneous radiofrequency ablation of hepatic tumors develop delayed, transient flulike symptoms that can be treated conservatively and are significantly related to the volume of tissue ablated. Familiarity with this postablation syndrome should facilitate appropriate management of affected patients.