Prevalence of Dental Implants and Evaluation of Peri-implant Bone Levels in Patients Presenting to a Dental School: A Radiographic Cross-Sectional 2-Year Study.

PURPOSE: To evaluate the number of patients with dental implants who present to a dental school clinic for screening and to report the prevalence of peri-implant bone level change detected on digital panoramic radiographs of those subjects. MATERIALS AND METHODS: Patient screening files for 9,422 patients over a 2-year period were examined to see how many patients presented with dental implants. Those patients with at least one implant were further evaluated by measuring the bone level on the mesial and distal sides of the implant using the screening radiograph. RESULTS: A total of 187 patients (2%) had at least one implant. In regard to implants, 423 were examined and 146 (33%) had no detectable bone loss defined as bone level below the top of the implant. When thresholds of bone loss were evaluated, 109 implants (25%) had ≥ 2 mm of bone loss on either the mesial or distal sides or both. The median bone loss was 1.74 mm for the 277 implants with detectable bone loss and 2.97 mm for the 109 implants that had ≥ 2 mm bone loss. Interestingly, patients who were ≥ 70 years of age had significantly (P = .03) more bone loss in the mandible compared with the maxilla, while patients who were 60 to 69 years of age had significantly greater loss in the maxilla. CONCLUSION: These data reveal that for patients presenting to the dental school for a screening over a 2-year period, 1.98% had one or more dental implants. Furthermore, those patients with implants had a minimum amount of bone loss as measured from the top of the implant.

Thickness of the Buccal Plate in Posterior Teeth: A Prospective Cone Beam Computed Tomography Study.

Buccal plate thickness is an important clinical parameter for postextraction implant treatment planning. The purpose of this study was to assess buccal plate thickness of the posterior maxilla and mandible using cone beam computed tomography (CBCT). A total of 265 patients and 934 teeth met the inclusion criteria for this study. CBCT volumes were taken and aligned for measurement at the ideal midsagittal cross-section. Buccal plate thickness was measured at 1, 3, and 5 mm apical to the alveolar crest. The frequency of thick (≥ 1 mm), thin (< 1 mm), and radiographic absence of the buccal plate were determined. The frequency of thin buccal plate decreases from anterior to posterior, with first premolars and first molar mesial roots most affected. Radiographic absence of the buccal plate was more common in the mandible, at first premolars, and among women. Thin and absent buccal plate are not uncommon in the posterior jaws; consequently, ridge preservation may be indicated even at posterior teeth.

Effect of Split-File Digital Workflow on Crown Margin Adaptation.

PURPOSE: Computer-aided design/computer-aided manufacturing (CAD/CAM) is becoming increasingly integrated into dental practice workflow at a pace that exceeds scientific validation. The aim of this study is to evaluate a complete digital split-file protocol relative to segmental digital and analog techniques for restoring a single maxillary anterior edentulous space with custom abutment and crown. MATERIALS AND METHODS: Four treatment workflows were assessed: complete digital (CD), segmental digital (SD), milled wax (AM), and heat pressed and hand waxed (AH) and heat pressed. The CD workflow "split" an abutment and crown into separate files to fabricate a zirconia abutment and both zirconia/lithium disilicate crown restorations. The SD workflow scanned the existing abutment for design of segmental restorations in zirconia, lithium disilicate, and milled wax (AM). The AH specimens were conventionally hand waxed. Both the AM and AH specimens were heat pressed with lithium disilicate. All restorations were evaluated with standardized measurements using scanning electron microscopy (SEM) as manufactured without internal adjustments and after manual adjustment. The number of adjustments, adjustment time, and location of adjustments were recorded. One-way ANOVA with repeated measures was used to report geometric means with 95% confidence intervals. RESULTS: The mean marginal gap after adjustment of the CD group was 69 µm, with an upper bound (UB) of 79 µm and a lower bound (LB) of 60 µm. SD group mean was 26 µm with an UB of 31 µm and LB of 22 µm. The AM group mean was 32 µm, with an UB of 49 µm and a LB of 20 µm; AH group mean of 26 µm with an UB of 34 µm and a LB of 20 µm. The SD, AM, and AH workflows were statistically similar (p = 1.000), and the CD workflow was statistically greater than the other three (p < 0.001). CONCLUSIONS: The split-file (CD) protocol results in marginal gap size within clinical standards after adjustment; however, 52 of the 60 digitally produced restorations showed a horizontal marginal offset that required adjustment for proper contours.

A cone beam computed tomography (CBCT) study of buccal plate thickness of the maxillary and mandibular posterior dentition.

BACKGROUND: Buccal plate thickness is of clinical importance in treatment planning for implants. The purpose of this study was to evaluate the buccal plate thickness in posterior dentate areas of both the maxilla and mandible using cone beam computed tomography in order to estimate the approximate distributions of this anatomic variable. METHODS: Two hundred and sixty-five subjects were included for a total of nine hundred and thirty-four roots assessed by cone beam computed tomography. CBCT scans were taken and evaluated at the ideal buccolingual cross-sections of each root at 1 mm, 3 mm, and 5 mm apical to the alveolar crest to measure buccal plate thickness. Data are reported by geometric means and 95% confidence intervals. RESULTS: Both arches demonstrated increasing buccal plate thickness from anterior to posterior. Maxillary teeth had a significant decrease in thickness from coronal to apical along the tooth root (P < 0.001), except at second molars. The first premolar and mesial root of the first molar were significantly thinner than all other roots in the maxilla. Conversely, the mandible demonstrated a significant increase in buccal plate thickness from coronal to apical (P < 0.001). The premolars were significantly thinner than all other roots. Age and sex were found to have limited impact on buccal plate thickness in both arches. CONCLUSIONS: Buccal plate thickness is highly dependent upon the arch position, tooth location, and measurement point, but age and sex have limited impact.

A lateral ridge augmentation study to evaluate a synthetic membrane for guided bone regeneration: an experiment in the canine mandible.

OBJECTIVES: To evaluate guided bone regeneration outcomes in defects protected with an in situ formed polyethylene glycol (PEG) hydrogel membrane as compared to a non-cross-linked collagen membrane (CM). MATERIAL AND METHODS: Four mandibular alveolar ridge defects were created in eight hound dogs. Regenerative procedures were randomly allocated to one of four groups consisting of freeze-dried bone allograft, which is referred to in this study as freeze-dried bone xenograft (FDBX) + PEG, autogenous bone (AB) + PEG, AB + CM, and AB alone. After 8 weeks, titanium dental implants were placed into augmented sites. After 8 weeks of allowed time for osseointegration, the animals were sacrificed to harvest block specimens for bone-to-implant contact (BIC) and ridge width histomorphometric analysis. RESULTS: Polyethylene glycol membranes had an exposure rate of 50% as compared to 12.5% for sites grafted with CM. Regenerative outcomes with respect to implant placement were least favorable for FDBX + PEG which had implants placed in 37.5% of augmented sites compared to 100% implant placement for all other groups. No statistically significant differences were noted between groups for ridge width measurements in implant and non-implant histologic sections (P > 0.05). Buccal BIC (%) values between treatment groups also failed to reach statistical significant difference (FDBX + PEG [60.2 ± 9.4]; AB + PEG [58.8 ± 8.5]; AB + CM [57.9 ± 12.8]; AB [61.0 ± 10.2]). CONCLUSION: When used in conjunction with FDBX, PEG had unpredictable bone formation and in most cases negatively impacted future implant placement.

Evaluation of 3 dental unit waterline contamination testing methods.

Previous studies have found inconsistent results from testing methods used to measure heterotrophic plate count (HPC) bacteria in dental unit waterline (DUWL) samples. This study used 63 samples to compare the results obtained from an in-office chairside method and 2 currently used commercial laboratory HPC methods (Standard Methods 9215C and 9215E). The results suggest that the Standard Method 9215E is not suitable for application to DUWL quality monitoring, due to the detection of limited numbers of heterotrophic organisms at the required 35°C incubation temperature. The results also confirm that while the in-office chairside method is useful for DUWL quality monitoring, the Standard Method 9215C provided the most accurate results.

Investigating the association between obstructive sleep apnea and periodontitis.

BACKGROUND: Obstructive sleep apnea (OSA) is a sleep disorder characterized by disruptions of normal sleep architecture. Chronic periodontitis is a chronic disease of the periodontium that elicits a general inflammatory response to local dental plaque. It has been suggested that periodontal disease may increase in severity with increasingly severe OSA because both disease entities share common inflammatory pathways, acting synergistically to alter the host response. The aim of this study is to analyze the association between severity of OSA and the prevalence/severity of periodontitis. METHODS: One hundred patients from a large veterans administration sleep study center (n = 26 normal, n = 21 mild, n = 19 moderate, n = 34 severe) diagnosed with an overnight polysomnogram underwent a comprehensive periodontal examination. Periodontal parameters measured included the following: 1) mean periodontal probing depth (PD); 2) clinical attachment level (CAL); 3) gingival recession; and 4) percentage of sites with bleeding on probing, plaque, PD ≥5 mm, and CAL ≥3 mm. RESULTS: Seventy-three percent of the sampled population had moderate/severe periodontal disease. χ(2) analyses revealed no significant differences in the prevalence of periodontal disease between the apnea-hypopnea index (AHI) groups, with a negligible Spearman correlation coefficient of 0.246 between AHI severity and periodontal disease severity categories. Analysis of covariance indicated a significant association between AHI severity categories and percentage of sites with plaque, after adjusting for age. Multivariable logistic regression analysis predicting moderate/severe periodontitis with AHI score, age, and smoking status indicated a significant association with age (P = 0.028) but no significant association with the other two predictors. CONCLUSION: OSA was not significantly associated with the prevalence of moderate/severe periodontitis and the periodontal parameters examined, except percentage plaque.

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.

Maxillary anterior ridge augmentation with recombinant human bone morphogenetic protein 2.

No human studies exist on the use of recombinant human bone morphogenetic protein 2 (rhBMP-2) on an absorbable collagen sponge (ACS) as a sole graft material for lateral ridge augmentation in large ridge defect sites. This series evaluates the treatment outcome of maxillary anterior lateral ridge augmentation with rhBMP-2/ACS. Twenty patients were treated with rhBMP-2/ACS and fixation screws for space maintenance. Cone beam volumetric tomography measurements were used to determine gain in ridge width, and a bone core biopsy was obtained. The mean horizontal ridge gain was 1.2 mm across sites, and every site gained width.

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.

A comparison of 2 laboratory methods to test dental unit waterline water quality.

The performance of 2 American Public Health Association standard laboratory methods, the R2A spread plate and the SimPlate(TM) for heterotrophic plate count, for quantifying heterotrophic microorganisms in dental waterline samples was evaluated. Microbial counts were underestimated on SimPlate(TM) compared with R2A, and the results indicated a poor correlation between the 2 methods.

Soft and hard tissue histologic dimensions around dental implants in the canine restored with smaller-diameter abutments: a paradigm shift in peri-implant biology.

PURPOSE: To evaluate the biologic width dimensions around implants with nonmatching implant-abutment diameters. MATERIALS AND METHODS: Five canines had their mandibular premolars and first molars removed bilaterally and replaced with 12 implants that had nonmatching implant-abutment diameters. On one side, six implants were placed in a submerged surgical approach, and the other side utilized a nonsubmerged approach. Two of the implants on each side were placed either 1 mm above, even with, or 1 mm below the alveolar crest. Two months later, gold crowns were attached, and the dogs were sacrificed 6 months postloading. Block sections were processed for histologic and histomorphometric analyses. RESULTS: The bone level, connective tissue length, epithelial dimension, and biologic width were not significantly different when the implants were initially placed in a submerged or nonsubmerged surgical approach. The bone level was significantly different around implants placed 1 mm above the crest compared to implants placed even with or 1 mm below the alveolar crest. The connective tissue dimension was not different for any implant level placement. The epithelial dimension and biologic width were significantly greater for implants placed 1 mm below the alveolar crest compared to implants placed even with or 1 mm above the alveolar crest. For five of six implant placements, connective tissue covered the implant/abutment interface. CONCLUSIONS: This study reveals a fundamental change in the biologic response to implants with nonmatching implant-abutment diameters. Unlike implants with matching implant-abutment diameters, the connective tissue extended coronally past the interface (microgap). This morphologic tissue alteration represents a significant change in the biologic reaction to implant-abutment interfaces and suggests that marginal inflammation is eliminated or greatly reduced in these implant designs.

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.

Human embryo culture media comparisons.

Every program of assisted reproduction strives to maximize pregnancy outcomes from in vitro fertilization and selecting an embryo culture medium, or medium pair, consistent with high success rates is key to this process. The common approach is to replace an existing medium with a new one of interest in the overall culture system and then perform enough cycles of IVF to see if a difference is noted both in laboratory measures of embryo quality and in pregnancy. This approach may allow a laboratory to select one medium over another but the outcomes are only relevant to that program, given that there are well over 200 other variables that may influence the results in an IVF cycle. A study design that will allow for a more global application of IVF results, ones due to culture medium composition as the single variable, is suggested. To perform a study of this design, the center must have a patient caseload appropriate to meet study entrance criteria, success rates high enough to reveal a difference if one exists and a strong program of quality assurance and control in both the laboratory and clinic. Sibling oocytes are randomized to two study arms and embryos are evaluated on day 3 for quality grades. Inter and intra-observer variability are evaluated by kappa statistics and statistical power and study size estimates are performed to bring discriminatory capability to the study. Finally, the complications associated with extending such a study to include blastocyst production on day 5 or 6 are enumerated.

Impact of early and high amino acid supplementation on ELBW infants at 2 years.

OBJECTIVE: The aim of the present study was to examine the effects of early and high intravenous (IV) amino acid (AA) supplementation on growth, health, and neurodevelopment of extremely-low-birth-weight (ELBW) infants throughout their first 2 years of life. METHODS: Infants were prospectively randomized in a double-masked fashion and treated for 7 days with either IV AA starting at 0.5 g · kg (-1) · day(-1) and increased by 0.5 g · kg(-1) every day to 3 g · kg(-1)· day(-) or starting at 2 g · kg (-1) · day(-1) of IV AA and advanced by 1 g · kg(-1) every day to 4 g · kg (-1) · day(-1). Plasma AA concentrations were determined by reverse-phase high-performance liquid chromatography. Survivors were longitudinally assessed with Bayley II Scales of Infant Development and physical, social, and global health. RESULTS: Forty-three of 51 survivors were studied. Mental Developmental Index (MDI) and Psychomotor Developmental Index were similar between groups; however, the early and high AA group had a lower MDI at 18 months. This difference disappeared at 2 years of age. The early and high AA group z score means for weight, length, and head circumferences were significantly lower than the standard AA group at most visits. Cumulative and single plasma AA concentrations correlated negatively with MDI and postnatal growth. CONCLUSIONS: ELBW infants who received early and high IV AA during the first week of life were associated with poor overall growth at 2 years.

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.

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.

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.

Early changes in plasma amino acid concentrations during aggressive nutritional therapy in extremely low birth weight infants.

OBJECTIVE: To examine the changes in plasma amino acid (AA) concentrations over time when extremely low birth weight infants are provided either a standard intravenous AA supplementation (standard AA) or an early and high supplementation regimen (early and high AA). STUDY DESIGN: Sixty-two infants were enrolled at birth in a randomized, double-masked, prospective fashion and treated for 7 days. The infants with standard AA concentrations received intravenous AA starting at 0.5 g/kg/d and increased by 0.5 g/kg every day to a maximum of 3 g/kg/d. Infants in the early and high AA group received 2 g/kg/d of intravenous AA soon after birth and advanced by 1 g/kg every day to 4 g/kg/d. Plasma AA concentrations were determined by high-pressure liquid chromatography on days 1, 3, and 7. RESULTS: Total AA concentrations, total essential AA concentrations, and total nonessential AA concentrations were significantly higher in the infants in the early and high AA group; essential AA concentrations and total AA concentrations were higher at 1 and 3 days, and nonessential AA concentrations were different only on day 3. There were significant differences between standard AA and early and high AA groups for all AA concentrations except the nonessential AAs Glu, Asn, Gly, Gln, Ala, and Tyr and the conditionally essential AA Cys. CONCLUSION: Infants who received early and higher parenteral AA had higher plasma AA concentrations.

The biofilm-controlling functions of rechargeable antimicrobial N-halamine dental unit waterline tubing.

OBJECTIVE: A study was conducted to test the biofilm-controlling functions of N-halamine tubing over an eight-month period. METHODS: A laboratory system, simulating a teaching dental clinic, was used to test rechargeable N-halamine tubing (T) compared to an untreated control (C) using the unit manufacturer's tubing. For the long-term study, a recharged tubing (RC) treated with bleach was used to compare with the test (T) and the control (C) tubing. Source tap water was cycled through the lines at 1.4 mL/minute, five minutes on and 25 minutes off, eight hours/day, five days/week. Every three weeks, samples of effluent, recovered adherent bacteria from inside tubing surfaces, and SEM images were examined for bacterial and biofilm growth. After sampling, a recharging solution of chlorine bleach (1 : 10 dilution) was run through T and RC lines, left overnight, and rinsed out the next morning. One-way ANOVAs and Spearman correlations were performed to detect significant differences for T, RC, and C, and determine significance with time period and source water, respectively. RESULTS: Mean log CFU/mL for C effluent > T (p = 0.028), and C tubing > T (p = 0.035). Spearman correlations were significant between effluent and source water level for T (rho = 0.817), and T tubing (0.750); between RC tubing and source water level (rho = 0.836), and time (rho = 0.745); and between C and time (rho = 0.873). SEM imaging confirmed the presence of biofilm inside RC and C, but not inside T. CONCLUSION: N-halamine tubing completely inhibited biofilm formation without negatively affecting the physical properties of the effluent water. Further research on N-halamine tubing using a pure water source is recommended, as T effluent bacterial levels reflected the source tap water quality and proliferation of planktonic bacteria with no biofilm activity.