Effect of filler contents on the bond strength of CAD/CAM resin crowns: New resin primer versus conventional silane agents

Purpose This study aims to evaluate the effects of resin primers containing methyl methacrylate (MMA) and silane agent on the bonding effectiveness of indirect resin composite blocks with three different filler contents.Methods A commercially available computer-aided design/computer-aided manufacturing (CAD/CAM) resin composite block and two experimental resin composite blocks with different filler contents were alumina-blasted and two surface treatments (primer and silane agent) were applied. The resin cement was built up, and the micro-tensile bond strength (μTBS) was measured after 24 hours, 1 month or 3 months of water storage (n = 24 per group). The fracture surfaces after μTBS measurements and resin block/cement interface were observed by scanning electron microscopy (SEM).Results The primer treatment group showed a significantly higher bond strength than the silane group only in F0 (filler content 0 wt%) group (P < 0.001). In the primer group, F0 and F41 (filler content 41 wt%) groups showed significantly higher bond strengths than F82 (filler content 82 wt%) group (P < 0.001). In contrast, in the silane group, F41 group showed significantly higher bond strength than F0 and F82 groups (P < 0.001), and F82 group showed significantly higher bond strength than F0 group (P < 0.001). SEM revealed that the matrix resin was partially destroyed on the fracture surface of the primer group, and an uneven interface surface was observed compared with that of the silane group.Conclusions MMA-containing primers showed higher bonding effectiveness to CAD/CAM resin composite blocks than the silane treatment.

Advanced statistical analyses to reduce inconsistencies in bond strength data focused on donor factors: A six-factor analysis using linear mixed and nonlinear regression models

PURPOSE

This study aimed to investigate the effects of the age and sex of tooth donors on dentin bond strength.

METHODS

A total of 38 extracted teeth (12 male and 26 female donors; age range: 17-82 years) were used in this study. In addition to donor age and sex, four other microtensile bond strength (μTBS) test specimen factors were evaluated: dentin position, bonding area, presence of voids at the interface, and computed tomography (CT) values of dentin. The μTBS was measured immediately (24 h) and 6 months after storage in water. After the μTBS testing, linear mixed and nonlinear regression models were used to analyze the effects of these factors on the μTBS data.

RESULTS

The results from the linear mixed model revealed that the bonding area (P = 0.02), presence of voids at the interface (P = 0.04), and storage time (P < 0.001) significantly affected bond strength. In contrast, no correlation was observed between the μ TBS and dentin position (P = 0.08) or sex (P = 0.07). The results of the nonlinear regression model with robust variance-covariance estimators revealed that age significantly affected bond strength (P < 0.001). In addition, a significant positive correlation was found between μTBS and age (P < 0.001), with nonlinearity (P = 0.002). However, no correlation was observed between the μTBS and CT values (P = 0.69) without nonlinearity (P = 0.39).

CONCLUSIONS

These findings suggest that bond strength increases with age until 60 years but not afterward.

Changes in occlusal relationships observed using an intraoral scanner in patients with an acquired open bite: A case report

PATIENTS

This case report describes a procedure for assessing changes in occlusal relationships in patients with acquired open bites due to temporomandibular joint disease using an intraoral scanner (IOS). A digital impression was made using the IOS at the initial visit. Subsequent impressions were made every 6 months using the IOS and magnetic resonance imaging (MRI) or computed tomography (CT). Standard triangulated language (STL) image files of two digital impressions at different points in time were superimposed, including the occlusal relationship with reference to the maxillary dentition. Finally, three-dimensional (3D) changes in the occlusal relationship over time were evaluated.

DISCUSSION

In Case 1, the superimposed STL image indicated almost no evident deviation of the mandible. Therefore, an orthodontic treatment was initiated. In contrast, in cases 2 and 3, where changes in the occlusal relationship continued, secondary treatment was postponed and patients continued to be monitored periodically. In case 3, even though left condyle resorption was progressive, the degree of open bite on the right side improved after 6 months. However, the open bite continued to progress for another 6 months despite the stability of the condyle.

CONCLUSIONS

Changes in the condylar shape observed using imaging may not always reflect changes in the occlusal relationship. In addition to changes in the condyles and eminences of the temporomandibular joint (TMJ), changes in the occlusal relationships of patients with acquired open bite should be evaluated using an intraoral scanner.

Reciprocal first night effect on rhythmic and non-rhythmic oromotor episodes in moderate to severe primary sleep bruxism: A retrospective physiological study

BACKGROUND

Sleep on the first night in a sleep laboratory is characterized by a lower sleep quality and frequency of rhythmic masticatory muscle activity (RMMA) than that on the second night in moderate to severe sleep bruxism (SB) patients.

OBJECTIVE

The aims of this study was to clarify the physiological factors contributing to the first night effect on oromotor activity during sleep and investigate whether physiological factors involved in the first night effect differed between rhythmic and non-rhythmic oromotor activities.

METHODS

Polysomnographic data collected on two consecutive nights from 15 moderate to severe SB subjects (F 7: M 8; age: 23.2 ± 1.3 [mean ± SD] years) were retrospectively analysed. Sleep variables, RMMA and non-specific masticatory muscle activity (NSMA) were scored in relation to episode types (i.e. phasic or tonic and cluster or isolated), sleep architecture and transient arousals. The relationships between nightly differences in oromotor and sleep variables were assessed. The distribution of oromotor events, arousals, cortical electroencephalographic power, RR intervals and heart rate variability were examined in relation to sleep cycle changes. These variables were compared between the first and second nights and between RMMA and NSMA.

RESULTS

Sleep variables showed a lower sleep quality on Night 1 than on Night 2. In comparisons with Night 1, the RMMA index increased by 18.8% (p  < .001, the Wilcoxon signed-rank test) on Night 2, while the NSMA index decreased by 17.9% (p  = .041). Changes in the RMMA index did not correlate with those in sleep variables, while changes in the NSMA index correlated with those in arousal-related variables (p  < .001, Spearman's rank correlation). An increase in the RMMA index on Night 2 was found for the cluster type and stage N1 related to sleep cyclic fluctuations in cortical and cardiac activities. In contrast, the decrease in the NSMA index was associated with increases in the isolated type and the occurrence of stage N2 and wakefulness regardless of the sleep cycle.

CONCLUSION

Discrepancies in first night effect on the occurrence of RMMA and NSMA represent unique sleep-related processes in the genesis of oromotor phenotypes in SB subjects.

Pre- and Postoperative Evaluation of Immediate and Early Implant Placement in Esthetic Areas with Pre-Extraction Facial Dehiscence: A Retrospective Clinical Study

The clinical requirement for a good esthetic result for immediate implant placement is the absence of dehiscence in the anterior facial alveolar bone. In the presence of dehiscence, it is recommended to use a connective tissue graft in addition to immediate implant placement or to change to early implant placement. However, the literature focusing on dehiscence is scarce, and the influence of different placement times and combined use of connective tissue graft on postoperative esthetics in cases with dehiscence is unclear. Therefore, we quantitatively evaluated the pre-extraction dehiscence morphology and postoperative changes in the facial tissue of implants in three groups: immediate implant placement (Group I), immediate implant placement with connective tissue graft (Group IC), and early implant placement (Group E). To this end, 52 implants were obtained (20 in Group I, 16 in Group IC, and 16 in Group E). A wider dehiscence increases the risk of soft tissue regression, which was one reason for choosing early implant placement. A combination of immediate implant placement and connective tissue graft, or early implant placement, tended to result in less soft tissue regression due to the thicker postoperative facial soft tissue volume.

Impact of internal design on the accuracy of 3-dimensionally printed casts fabricated by stereolithography and digital light processing technology

STATEMENT OF PROBLEM

Altering the internal design of 3-dimensionally (3D) printed dental casts may help to reduce material and time consumption. However, it remains unclear whether such changes would compromise the accuracy of the casts. Further research is also needed to determine the optimal internal design that would maximize printing accuracy.

PURPOSE

The purpose of this in vitro study was to evaluate the impact of internal design on the accuracy (trueness and precision) of 3D printed dental casts fabricated by stereolithography (SLA) and digital light processing (DLP) technology.

MATERIAL AND METHODS

A reference digital cast was obtained by scanning a maxillary typodont with an intraoral scanner to create 4 types of internal designs, including hollow interior with perforated base (HWB), hollow interior without base (HB), all solid (S), and internal support structure with perforated base (SWB). Digital casts with different internal designs were printed by two 3D printers with different technologies (SLA and DLP). The printed casts were scanned by a desktop scanner to obtain standard tessellation language (STL) format research digital casts. All reference and research digital casts were imported into a software program for comparison and analysis of accuracy. Differences between the reference and research digital casts were quantitatively indicated by the root mean square (RMS) value. The Kruskal-Wallis 1-way ANOVA was used to test significant differences between the different internal design types and the Mann-Whitney U test was used to test significant differences between the two 3D printers (α=.05).

RESULTS

The Kruskal-Wallis 1-way ANOVA revealed significant differences in the trueness and precision of different internal design types (all P<.001) for casts printed by both 3D printers. The trueness and precision were significantly worse for the HB design than for the other design types for casts printed by both 3D printers (all P<.05). Regardless of the design type, the trueness was significantly better for casts printed by the SLA-based printer than for casts printed by the DLP-based printer (all P<.05). The precision was significantly worse for casts printed by the SLA-based printer than for casts printed by the DLP-based printer (all P<.05).

CONCLUSIONS

The internal design may affect the accuracy of 3D printing. The base is necessary to ensure the accuracy of 3D printed dental casts, whereas the internal support structure did not affect the accuracy of 3D printed dental casts. An all-solid design led to higher precision, but not higher trueness. Dental casts printed with SLA technology have higher trueness and lower precision than those printed with DLP technology.

Maxillary labial peri-implant hard and soft tissue alteration observed on cross-sectional dimension: a 2-year prospective observational study

OBJECTIVES

To evaluate how peri-implant hard and soft tissue height (BH, MH) alter after final prostheses placement related to labial hard and soft tissue thickness (BW, MW).

MATERIALS AND METHODS

Forty-five platform-switched implants were classified into four groups according to BW and MW: type 1 (thick BW and thick MW), type 2 (thick BW and thin MW), type 3 (thin BW and thick MW), type 4 (thin BW and thin MW). Tissue resorption was evaluated on cone-beam CT images taken at final prostheses placement, at 1-year follow-up, and at 2-year follow-up. Kruskal-Wallis test and post hoc Mann-Whitney test were applied; significance was set to 0.05.

RESULTS

BH resorption was 0.13 ± 0.12 mm in type 1, 0.26 ± 0.17 mm in type 2, 0.09 ± 0.09 mm in type 3, 0.94 ± 0.19 mm in type 4. Differences between type 1 and 4, type 2 and 4, and type 3 and 4 were statistically significant (p < 0.001, p = 0.005, p < 0.001, respectively). MH resorption was 0.10 ± 0.09 mm in type 1, 0.36 ± 0.16 mm in type 2, 0.12 ± 0.12 mm in Type 3, 0.79 ± 0.23 mm in type 4. Differences between type 1 and 2, type 1 and 4, type 2 and 3, type 2 and 4 and type 3 and 4 were statistically significant (p < 0.001).

CONCLUSIONS

Significantly less BH/MH resorption occurs around implants with thick BW/MW than those with thin BW/MW in 2 years. Implants with thick peri-implant soft tissue resulted in significantly less tissue resorption in second year after final prostheses placement.

Implant deformation and implant-abutment fracture resistance after standardized artificial aging: An in vitro study

BACKGROUND AND PURPOSE

Zirconia abutments have been widely adopted in clinical implant practice. The unique mechanical properties of zirconia may significantly affect the long-term prognosis of implant treatments. The purpose of this study was to investigate the influence of abutment material on implant deformation and fracture resistance of internal conical connection implant-abutment complexes of two diameters after standardized artificial aging.

MATERIALS AND METHODS

Thirty original abutments (one-piece titanium, one-piece zirconia, zirconia with alloy base) with two diameters (regular, narrow) were connected to internal conical connection implants and subjected to a standardized artificial aging process consisting of thermal cycling and mechanical cyclic loading. Microcomputed tomography (μCT) scans of implant bodies were performed before and after aging. 3-dimensional images of implant bodies were generated from the μCT scans and aligned for before and after aging to calculate the volumetric deformation amount. Finally, fracture resistance was measured using a mechanical static loading test for the surviving aged and 30 brand-new specimens.

RESULTS

All specimens survived artificial aging. No significant difference in implant deformation was found in the regular groups (p = 0.095). In narrow groups, the one-piece zirconia group showed significantly less deformation (p < 0.0001). For fracture resistance, no significant decrease was observed after aging in any group (p > 0.05). One-piece zirconia abutments showed significantly lower strength than the other two materials for both diameters (p < 0.0001).

CONCLUSIONS

In the regular diameter system, abutment material had no significant influence on the tested mechanical property degradation after simulated long-term oral use. The mechanical performance of narrow diameter one-piece zirconia abutments differed from the other two materials. For optimal performance, one-piece zirconia abutments should be adopted only in anterior regions.

Fracture strength and behavior of resin-faced CAD/CAM anterior crowns

The fracture strength and behavior of a novel resin-faced computer-aided design/computer-aided manufacturing (CAD/CAM) crown were investigated to evaluate application to the anterior teeth. Resin-faced CAD/CAM crowns were fabricated by arranging a resin composite on a frame prepared from a CAD/CAM resin block. The fracture strength was evaluated after 24 h of complete polymerization (day 0) and after water immersion for 30 days (day 30). Uniaxial loading was applied to the center point between the incisal edge and cingulum (loading point 1) or at 1.5 mm from the incisal edge (loading point 2). There was no significant difference in the fracture strength of the resin-faced CAD/CAM crowns between day 0 and 30 at loading point 1. At loading point 2, they exhibited decreased fracture strength after water immersion; however, the mean strength was still >1 kN. This novel crown showed good mechanical properties to serve as a prosthesis for the anterior teeth.

Abutment removal torque and implant conical surface morphological changes after standardized artificial aging: An in vitro study

STATEMENT OF PROBLEM

Zirconia abutments have become popular as they provide favorable esthetic outcomes. However, studies investigating how abutment material affects abutment screw torque performance and implant conical surface morphological changes in internal conical connection systems are scarce.

PURPOSE

The purpose of this in vitro study was to investigate the influence of abutment material on abutment removal torque and implant conical surface morphological changes in internal conical connection implant-abutment assemblies of 2 diameters after simulated long-term oral use.

MATERIAL AND METHODS

Thirty abutments of 3 materials (1-piece titanium, 1-piece zirconia, zirconia with alloy base) and 2 diameters (regular, narrow) made by the original manufacturer were connected to internal conical connection implants and subjected to a standardized artificial aging process consisting of thermal cycling and mechanical cyclic loading with parameters corresponding to anterior and posterior mastication scenarios simulating long-term oral use. An abutment removal torque test was done before and after aging. Morphological changes in the implant conical contact surface were observed with a scanning electron microscope (SEM). Initial and after-aging torque loss values were calculated and analyzed separately with 1-way ANOVA and Tukey HSD post hoc tests (α=.05).

RESULTS

All specimens survived artificial aging. For initial and after-aging torque loss, the 1-piece zirconia groups showed significantly greater values (P<.001) for both diameters. In the SEM observation, the 1-piece zirconia groups showed distinct widespread surface damage while the other groups exhibited only minor damages.

CONCLUSIONS

Regardless of diameter, 1-piece zirconia abutments tend to induce more abutment removal torque loss and implant conical surface morphological changes than those with metal connections, both initially and after simulated long-term oral use. Zirconia abutments with an alloy base performed similarly to 1-piece titanium abutments.

Impact of number of functional teeth on independence of Japanese older adults

AIM

To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence.

METHODS

Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed.

RESULTS

This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant.

CONCLUSIONS

The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.

Cross-sectional and longitudinal assessment of subchondral cysts in temporomandibular joints: Clinical and MRI study with a mean follow-up of 66 months

PURPOSE

This observational study aimed to elucidate the pathophysiology of subchondral cysts (SC) in the temporomandibular joint (TMJ) and examine the results of conservative therapy administered to patients with SCs in the TMJ.

METHODS

The study included 41 patients with SCs, extracted from 684 consecutive patients who underwent magnetic resonance imaging (MRI). The anatomical features of SCs and positional abnormalities of the articular disc were initially evaluated using MRI. A second MRI examination was performed for 28/41 patients at 40-107 months (mean, 66 months) after the first MRI. The joint space, anteroposterior width of the condylar head (WiC), articular eminence angle (AEA), and visual analog scale of jaw pain (VAS) were assessed alongside the MRI examinations.

RESULTS

Most SCs were present in the anterosuperior and central condyle. Disc displacement was observed in 100% of 42 TMJs with SCs. Of the 29 joints in 28 patients, SCs in 19 joints resolved with time, whereas SCs in 10 joints persisted. A significant increase in the WiC and a significant decrease in AEA and VAS scores were observed on the second MRI scan.

CONCLUSIONS

SCs tended to form in the anterosuperior and central parts of the condyle, where mechanical loading was likely to be applied. SCs are strongly associated with articular disc displacement. Two-thirds of SCs resolved over time, accompanied by resorption and osteophytic deformation of the condyle. SC might not be an indicator for the start of surgical treatment, and nonsurgical treatment could improve the clinical symptoms of patients with SCs.

AB0621 Characteristics of Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis With Severe Peripheral Neuropathy

Background

Peripheral neuropathy is one of major manifestations of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and has a significant impingement on patients’ quality of life.1,2

Objectives

The aim of this study was to clarify clinical features of AAV patients with peripheral neuropathy and identify risk factors for severe motor neuropathy.

Methods

All consecutive patients with active, treatment-naïve AAV who were admitted to our hospital between April, 2012 and October, 2021 were reviewed. Patients were divided into two groups according to the presence or absence of peripheral neuropathy, and their baseline clinical characteristics were compared.

Results

A total of 76 patients (microscopic polyangiitis, MPA, n=37, granulomatosis with poly angiitis, GPA, n=24, eosinophilic GPA, EGPA, n=15) were included in the study. Among them, 28 patients (36.8%) had peripheral neuropathy including 12 with MPA, 4 with GPA, and 12 with EGPA. The clinical characteristics of all patients with peripheral neuropathy were younger age (66.0 years versus 74.5 years, p<0.05) and showed higher white blood cell counts (11500/μL versus 8800/μL, p<0.05), higher blood eosinophil counts (788.5/μL versus 139.0/μL, p<0.05), higher creatinine clearance (77.3 mL/min versus 56.3 mL/min, p<0.05), higher levels of serum immunoglobulin (Ig)E (660 IU/mL versus 125 IU/mL, p<0.05), and IgG4 (361.5 mg/dL versus 84.0 mg/dL, p <0.05). In patients with EGPA, the most susceptible type to peripheral neuropathy, 80% of the patients had peripheral neuropathy. Comparison between patients with EGPA with peripheral neuropathy and those without demonstrated significantly younger age (56.0 years versus 80.0 years, p<0.05) and higher blood eosinophil counts (7832/μL versus 2340/μL, p<0.05) were characteristic for the presence of peripheral neuropathy. Patients with EGPA with motor neuropathy (n=8) showed higher white blood cell counts (26850//μL versus 8650//μL, p <0.05) and higher blood eosinophil counts (13134//μL versus 3436//μL, p<0.05) compared with those with only sensory neuropathy (n=4).

Conclusion

Our current study has shown that patients with EGPA are more prone to peripheral neuropathy than patients with MPA or GPA. Severe motor neuropathy was observed only in patients with EGPA and associated with more intense eosinophilic inflammation. Our results suggest that molecular targeted therapy that improves eosinophilic inflammation such as anti-IL-5 therapy is beneficial for peripheral neuropathy.

References

[1]RUTGERS, Abraham; KALLENBERG, Cees GM. Peripheral neuropathy in AAV—when vasculitis hits a nerve. Nature Reviews Rheumatology, 2012, 8.3: 127-128.

[2]NAKAZAWA, Daigo, et al. Pathogenesis and therapeutic interventions for ANCA-associated vasculitis. Nature Reviews Rheumatology, 2019, 15.2: 91-101.

Disclosure of Interests

None declared

Prosthetic and orthodontic rehabilitation of a patient with severe maxillary central incisor root resorption associated with impacted maxillary canines

OBJECTIVE

This case report describes the orthodontic and prosthetic rehabilitation of a patient with resorption of the roots of the maxillary central incisors due to the ectopic maxillary canines.

CLINICAL CONSIDERATIONS

A 16-year-old woman presented with severe resorption of the roots of the maxillary central incisors due to the ectopic maxillary canines. The impacted canines were orthodontically tracted with a lingual arch-supporting temporary central incisors and vertical elastics, and, undesirable root proximity was later corrected by moving the canines distally 1.5 mm apart. Gingival replacement cords were placed into the gingival sulcus of the canines, and tooth preparation was performed along with rotary gingival curettage of the interdental papilla. Convex form was provided for the mesial and labio-distal subgingival contour of the restorations.

CONCLUSIONS

The creeping attachment of the interdental papilla was successfully achieved by the orthodontic arrangement of interdental distance and the prosthetic stimulus via the retraction cord, rotary curettage, and convex mesial subgingival contours. In addition, selective retraction of the labio-distal gingiva by overcontoured restorations moved the gingival zenith position (GZP) distally. Finally, the canine crown morphology and gingival level mimicked the central incisors.

CLINICAL SIGNIFICANCE

This clinical report introduces a treatment workflow of to recover the esthetic disturbance due to severe root resorption of the maxillary central incisors associated with impacted maxillary canines. The present orthodontic and prosthetic procedure can improve both hard and soft tissue esthetics and could be used in similar cases, such as malformed teeth and tooth autotransplantation or transposition with disturbances in the interdental papilla height or the GZP.

Effect of tooth temperature on the dentin bonding durability of a self-curing adhesives: The discrepancy between the laboratory setting and inside the mouth

A two-bottle self-curing universal adhesive (Tokuyama Universal Bond; Tokuyama Dental) that does not require a long waiting time or light curing after application of the bonding material has been developed. This study aimed to evaluate the influence of tooth and adhesive temperature during the bonding procedure on the effectiveness of dentin bonding. The results showed that the tooth temperature affected the effectiveness of the dentin bonding; therefore, to determine the precise bonding ability in the laboratory, the temperature of the tooth must be raised until it is the same as that of the oral cavity. In addition, the temperature of the material did not affect bonding effectiveness; this result confirms that it does not matter whether the refrigerated product is used soon after its removal from the refrigerator or after it reaches room temperature in the clinic.

The efficacy of immediate implant placement in the anterior maxilla with dehiscence in the facial alveolar bone: A case series

BACKGROUND

There is no clear evidence that immediate implant placement can be applied to cases with dehiscence in the facial alveolar bone prior to extraction.

PURPOSE

To evaluate the results of immediate implant placement in the anterior maxilla with facial alveolar bone dehiscence.

MATERIALS AND METHODS

We super positioned pre- and post-operative cone-beam computed tomography (CBCT) three-dimensional reconstruction images. A CBCT was taken before tooth extraction (T0), when the definitive restoration was placed (T1), and 1 year after placing the definitive restoration (T2). The depth and width of the dehiscence at T0, and the height and width of the facial hard and soft tissues are measured at the implant site at T1 and T2. We calculated the change in the amount of hard and soft tissues from T1 to T2 and determined the correlation between preoperative facial alveolar bone morphology and postoperative gingival recession.

RESULTS

13 women and 7 men were recruited. A total of 20 implants were evaluated. The implant survival rate was 100%. The mean facial alveolar bone dehiscence width was 3.9 ± 1.6 mm, and the mean depth from platform level was 2.9 ± 1.7 mm. The mean implant body exposure on the buccal was 4.8 ± 1.7 mm, and the mean socket width gap was 2.1 ± 0.8 mm. At T1, the mean facial hard tissue width was 2.1 ± 0.7 mm, and the mean height was 2.0 ± 0.7 mm. The mean change in vertical gingival recession from T1 to T2 was 0.5 ± 0.5 mm. We found a positive correlation between facial alveolar bone dehiscence width and gingival recession (r = 0.46, p-value = 0.04) and between dehiscence depth and gingival recession (r = 0.48, p-value = 0.03).

CONCLUSIONS

The results of our CBCT superposition method indicated that immediate implant placement can be considered in patients with facial alveolar bone dehiscence. However, there may be a higher risk of gingival recession with wide or deep dehiscence.

CBCT analysis of the tissue thickness at immediate implant placement with contour augmentation in the maxillary anterior zone: a 1-year prospective clinical study

Background

Immediate implant placement with simultaneous contour augmentation such as guided bone regeneration (GBR) or connective tissue grafting (CTG) has been widely performed. However, few prospective studies have evaluated both peri-implant bone and soft tissue changes between the preoperative and postoperative periods. The purpose of this study is to quantify the horizontal dimensional changes of the facial bone and soft tissue following immediate implant placement with contour augmentation.

Material and methods

Twenty patients who underwent immediate implant placement in the anterior maxilla received GBR and CTG (test group) or GBR only (control group). Cone-beam computed tomography (CBCT) scans were taken preoperatively and 1 year after the definitive prosthesis connection, and then, they were superimposed. On the CBCT images of the two stages, the horizontal distance from the implant platform to the facial bone surface (BW) and the horizontal soft tissue width (GW) were measured at the implant platform level and 2 mm apical to the implant platform level. The sum of BW and GW (=TW) was used to assess the facial mucosal contour.

Results

BW decreased significantly from preoperative to 1 year after prosthesis connection with a mean decrease of 0.47 mm (P =0.021) in the control group and a mean decrease of 0.50 mm (P = 0.019) in the test group at the implant platform level. GW increased significantly with a mean increase of 1.37 mm (P =0.005) in the test group at the implant platform level. TW decreased significantly with a mean decrease of 0.46 mm in the control group (P =0.049) but increased significantly with a mean increase of 0.87 mm in the test group (P =0.005) at the implant platform level.

Conclusions

Immediate implant placement with CTG showed a soft tissue gain of 1.37 mm compensated for bone resorption, thus still preserving the preoperative mucosal contour. CTG should be performed with immediate implant placement in cases where preoperative mucosal contours need to be maintained.

Relative risk of positional and dynamic temporomandibular disc abnormality for osteoarthritis-magnetic resonance imaging study

Dynamic articular disc abnormality (wR, with reduction; woR, without reduction) is well known as the risk factor for temporomandibular joint osteoarthritis (TMJOA). However, there are few speculations on the potential risk of positional disc abnormalities for TMJOA. The purpose of this study was to investigate the relative risk of positional abnormality and dynamic abnormality of the temporomandibular disc for OA after the three-dimensional interpretation of all the sagittal and coronal planes of magnetic resonance (MR) data in a large dataset of consecutive subjects. Experimental samples consisted of images of 1356 TMJs of patients. A diagnosis of disc state was established in each TMJ utilising a 1.5T MR imaging scanner. A binary logistic regression analysis was performed to identify the significant associations between the outcome (dependent variable: the presence of OA) and the predictors (covariates: age, sex, dynamic disc state [the presence of woR], and 5 categories of the positional disc state [NA, no abnormality; SW, sideways; pADD, partial anterior; cADD, complete anterior; PDD, posterior]). Based on the result of the binary logistic regression analysis, the presence of woR showed an odds ratio of 14.1 (P < .05). In addition, compared with the joints NA, those with SW and cADD showed odds ratios of 5.62 and 10.88, respectively (P < .05). Despite the limitations of the study, in the positional disc abnormalities, sideways disc displacement and complete anterior disc displacement could be associated with the occurrence of TMJOA. All the coronal and sagittal MR images should be evaluated to assess intra-articular joint disorders accurately.

Number of functional teeth more strongly predicts all-cause mortality than number of present teeth in Japanese older adults

Aim

Previous studies on the association between intraoral conditions and mortality in community‐dwelling older individuals reported that fewer present teeth (PT) are significant risk factors for mortality. However, how the number of PT relative to the number of functional teeth (FT), including both present and rehabilitated teeth, influences mortality has not been investigated fully. This study examined the impact of the number of FT on mortality among community‐dwelling Japanese older adults.

Methods

This study was a retrospective, observational and population‐based follow‐up study, which examined 1188 older individuals who participated in an annual geriatric health examination from 2009 to 2015. The average follow‐up period was 1697.0 ± 774.5 days. The primary outcome was all‐cause mortality at follow‐up. The numbers of PT and FT of each participant were counted during an oral examination. In addition, demographics, clinical variables, blood nutrient markers, physical functions and perceived masticatory function were measured.

Results

Kaplan–Meier analysis, followed by a log‐rank test, revealed that fewer PT (P < 0.001) and FT (P = 0.002) were significantly associated with a reduced survival rate. Cox's proportional hazard analysis indicated that the number of FT, but not the number of PT, was a significant independent mortality risk factor after adjusting for demographics, clinical variables, nutrient markers and physical functioning (P = 0.036, hazard ratio: 2.089).

Conclusions

Current results suggest that the number of FT more strongly predicts all‐cause mortality than the number of PT among community‐dwelling older adults. Further studies are necessary to consider the confounding of socioeconomic status and disability status. Geriatr Gerontol Int 2020; ••: ••–••.

Catheter-related bloodstream infection due to Rhodotorula mucilaginosa with normal serum (1→3)-β-D-glucan level

Rhodotorula species are environmental basidiomycete yeasts that have emerged as a cause of fungemia in immunocompromised hosts. The insertion of a central venous catheter was identified as a major risk factor for Rhodotorula fungemia. Few cases reports have reported (1→3)-β-D-glucan testing at the onset of Rhodotorula mucilaginosa fungemia. We report a case of catheter-related bloodstream infection due to R. mucilaginosa. Serum β-D-glucan level was normal at the onset of the bloodstream infection. It took 5 days to culture the isolate. The patient's fever persisted after empiric treatment with micafungin, and a switch to oral voriconazole immediately resolved the fungemia.

Clinical significance of dual-energy CT-derived iodine quantification in the diagnosis of metastatic LN in colorectal cancer

BACKGROUND

The purpose of this study was to evaluate the diagnostic value of dual-energy computed tomography (DECT) in detecting lymph node (LN) metastasis in patients with colorectal cancer.

METHODS

Data from 81 LNs from 28 patients with colorectal adenocarcinoma were retrospectively analyzed. All patients received DECT before surgery without any neoadjuvant therapy. The diagnostic value was assessed using the iodine concentration (IC).

RESULTS

In the pathological findings, 35 (43.2%) LNs from 13 patients were metastatic and 46 (56.8%) LNs from 17 patients were non-metastatic. The mean IC of metastatic LNs in the portal venous phase (PP) was 1.60 mg/ml, which was significantly lower compared with non-metastatic LNs (3.25 mg/ml, p < 0.001). Receiver operating characteristic (ROC) analysis revealed that the IC in PP had the highest ability to discriminate LN metastasis (area under the ROC curve [AUC] 0.932). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of IC in PP (cutoff 2.1 mg/ml) were 87.0%, 88.6%, 85.3%, 90.0%, and 87.9%, respectively. When clinically obvious metastatic LNs in conventional CT findings were excluded, 50 LNs remained (5 metastatic and 45 non-metastatic LNs). In this subgroup analysis, the IC in PP remained the most powerful predictor of metastatic LNs (cutoff: 2.1 mg/ml, AUC 0.933).

CONCLUSIONS

The evaluation of IC in DECT may improve the diagnostic capabilities of discriminating metastatic LNs. This method may be particularly useful when conventional CT findings lead to equivocal results.

Risk of perforation during dilation for esophageal strictures after endoscopic resection in patients with early squamous cell carcinoma

BACKGROUND AND STUDY AIMS

Growing evidence suggests that esophageal stricture frequently develops after endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) in early esophageal cancer patients, with an incidence proportional to the greater extent of mucosal defects resulting from improved EMR/ESD techniques. There seems to be a potential risk of perforation during bougienage in such patients.

PATIENTS AND METHODS

648 stricture dilations for 78 lesions in 76 patients were consecutively included. The outcomes after combined use of Maloney and Savary wire-guided bougienage for esophageal strictures after EMR/ESD were analyzed in a single-institute retrospective case series study. The perforation rate was determined and risk factors for perforation were identified.

RESULTS

Patients underwent a median of 5.0 dilation procedures performed over a median 3.0 months for post-EMR/ESD strictures. Initial dilation was done a median 14 days following endoscopic resection. Perforations developed in seven patients (7/648 dilation procedures, 1.1%), all in the lower esophagus, and bleeding occurred in one patient (0.1% dilations). Two independent risk factors for development of perforation during dilation therapy for post-EMR/ESD stricture were identified: multiple dilations (odds ratio [OR] 1.2; P=0.012), and lower site of stricture (OR 12.8; P=0.043). Dysphagia was ameliorated by the dilations, and no patient required surgery.

CONCLUSIONS

A specific emerging risk of perforation in dilation therapy for post-EMR/ESD strictures was identified. Carefully planned treatment is necessary in patients with severe post-EMR/ESD strictures especially strictures requiring multiple dilations or located in the lower esophagus.

Mean power frequency during speech in myalgia patients

The purpose of this study was to clarify a difference of mean power frequency (MPF) during speech between control and myalgia patients groups. The control group consisted of 20 asymptomatic volunteers and the myalgia patients group consisted of 19 patients. A bilateral electromyogram (EMG) of masseter muscles during speech movement was recorded using surface electrodes, and the EMG data were stored and analysed with a computer-based EMG analyzer. The MPF during the entire duration of EMG burst during speech was compared between the control and myalgia group. The average (SD) MPFs during speech in the myalgia and control groups were 214.06 (17.23) and 183.39 (22.35) Hz, respectively, significantly higher in the former (P < 0.001). In myalgia patients, firing rates or recruitment of motor units innervated by high threshold motoneurons might decrease and lead to a higher MPF. The result suggests the possibility that muscle pain, that is a subjective experience, could be evaluated by objective data that is calculated from electromyographic activities which is recorded during speech.

AATF mediates an antiapoptotic effect of the unfolded protein response through transcriptional regulation of AKT1

Endoplasmic reticulum (ER) stress-mediated cell death plays an important role in the pathogenesis of chronic diseases including diabetes and neurodegeneration. Although pro-apoptotic programs activated by ER stress have been extensively studied, identification and characterization of anti-apoptotic programs that counteract ER stress is currently incomplete. Through the gene expression profiling of β-cells lacking WFS1, a causative gene for Wolfram syndrome, we have discovered a novel anti-apoptotic gene of the unfolded protein response (UPR), apoptosis antagonizing transcription factor (AATF). Here we study the regulation of AATF, identify its target genes, and determine the basis for its anti-apoptotic activities in response to ER stress. We show that AATF is induced by ER stress through the PERK-eIF2α pathway and transcriptionally activates the Akt1 gene through Stat3, which sustains Akt1 activation and promotes cell survival. Ectopic expression of AATF or a constitutively active form of AKT1 confers on cells resistance to ER stress-mediated cell death, whereas RNAi-mediated knockdown of AATF or AKT1 renders cells sensitive to ER stress. We also discovered positive crosstalk between the AATF and WFS1 signaling pathways. Thus, WFS1-deficiency or AATF-deficiency mediates a self-perpetuating cycle of cell death. Our results reveal a novel anti-apoptotic program relevant to treatment for diseases caused by ER stress-mediated cell death.

Occlusal interference during mastication can cause pathological tooth mobility

BACKGROUND AND OBJECTIVE

Despite little evidence regarding the relationship between tooth mobility and nonworking contact, the evaluation of occlusion is performed mainly by the detection of premature and/or nonworking contacts during tapping movements and lateral excursion. The hypothesis of this study is that occlusal contact during mastication is potentially traumatic to periodontal tissue. It clarifies the relationship between chewing patterns and the status of periodontal tissue.

MATERIAL AND METHODS

Subjects included 73 adults, 20-29 years of age (39 men and 34 women), with complete sets of teeth and no history of orthodontic treatment or periodontal disease. The closing chewing patterns of each subject were classified into three groups by the Masticatory Deviation Index, which depicts the deviation from the normal chewing patterns within 5 mm from the intercuspal position. Periotest was used to diagnose teeth mobility and the values were compared among the three groups.

RESULTS

The present study indicates that the chewing movements which deviated from the normal chewing movements increased the mobility of specific types of teeth.

CONCLUSION

The results of this study imply a relationship between chewing movements and tooth mobility and indicate that functional evaluation of occlusion is necessary for the examination of periodontal tissue. Occlusal evaluation with border and tapping movements might be insufficient, and functional occlusal evaluation during chewing movements can be clinically useful for using to evaluate periodontal tissue.

Clinical effectiveness of cognitive behavior therapy in the management of TMD

PURPOSE

This study aimed to investigate whether cognitive behavior therapy (CBT) was effective as a standard intervention for temporomandibular disorders (TMD).

MATERIALS AND METHODS

The subjects were 134 TMD outpatients with no history of treatment for TMD. They had pain persisting for 1 month or more and/or limited jaw movement. All patients underwent CBT. Symptom fluctuation was evaluated by a self-administered questionnaire.

RESULTS

Symptoms had disappeared and improved in 112 patients within 2 months.

CONCLUSION

It was suggested that most TMD symptoms can be relieved only by CBT in less than 2 months without further intervention.

Biomechanical stress in bone surrounding an implant under simulated chewing

The concept of reducing nonaxial loading of dental implants has been widely regarded as the standard procedure. The aim of this study was to reveal the biomechanical stress distribution in supporting bone around an implant and a natural tooth under chewing function. Three-dimensional finite element models of the mandibular first molar and the titanium implant both with the mandible in the molar region were constructed. The directions of displacement constraints were determined according to the angles of the closing pathways of chopping type and grinding type chewing patterns. The tooth model showed smooth stress distribution in the supporting bone with low stress concentration around the neck of the tooth. The implant model showed stress concentration in the supporting bone around the neck of the implant, especially in the buccal area. The grinding type model of the implant showed higher tensile stress concentration than the chopping type model at the lingual neck of the implant. The results of this study suggested the importance of considering occlusion under chewing function for understanding the biomechanics of oral implants.

Influence of abutment substrates on the colour of metal-free polymer crowns

New-generation composite materials have excellent strength and wear resistance, and thus can be used to make metal-free crowns. However, composite materials are translucent, and so when using them to make metal-free crowns, it is necessary to take the effect of the abutments into consideration. In this study, five types of materials including three types of new-generation composite materials, a conventional composite material, and a ceramic material were used to examine the translucency (contrast ratio) of the materials and the effects of the colour of the abutments on the final appearance of metal-free crowns. It was found that the materials varied slightly from one-another in translucency and that it was possible to reproduce the desired colour when gold alloy was used for the background. However, it was difficult to produce an adequate colour match when silver-palladium alloy was used for the background. When a tooth colour material that was darker than the target colour was used for the abutment teeth, some materials could not reproduce the target colour satisfactorily.

Fracture resistance of pressable glass-ceramic fixed partial dentures

The aim of the present study was to evaluate the mechanical strength of the Empress2 system, which is based on the use of a high-strength glass--ceramic core of lithium disilicate, and the fracture resistance of fixed partial dentures fabricated with this material. To evaluate mechanical strength, four types of ceramic materials were tested for four-point flexural strength and diametral tensile strength: Empress2 core material, Empress2 layering porcelain, conventional Empress material and Dicor. Then, using Empress2, conventional Empress and Dicor, actual clinical type anterior fixed partial dentures were fabricated for fracture testing. The results showed that the Empress2 core material, at 329 MPa, has more than twice the flexural strength of conventional materials and at 271 MPa, more than four times the diametral tensile strength of conventional materials. Furthermore, fixed partial dentures fabricated with Empress2 had a fracture resistance of 1424 N. That is, they were more than twice as fracture resistant as fixed partial dentures made with conventional materials.

Influence of abutment substrate and ceramic thickness on the colour of heat-pressed ceramic crowns

All-ceramic crowns made of leucite-based heat-pressed ceramics are widely used to restore non-vital teeth in conjunction with various post and core materials. However, as some light passes through the ceramic, the colour of the abutment substrate can negatively affect the final aesthetic appearance of the all-ceramic crown. In this study, we made background specimens simulating gold-alloy cast posts and other simulating porcelain veneered cast posts, overlaid different thickness of heat-pressed ceramic on these background specimens, and measured the shifts in colour. We found that, when the background specimen was a gold alloy, the background colour had an effect on the apparent colour, unless the ceramic was more than 1.6 mm thick. When the background specimen was porcelain veneered, the background colour had no evident effect, even when the ceramic was not very thick. Therefore, when making a restoration using a leucite-based heat-pressed ceramic crown, it is advisable to use tooth-coloured materials such as a porcelain veneered cast post, if you will not be able to make the ceramic more than 1.6 mm thick.

Stress analysis of metal-free polymer crowns using the three-dimensional finite element method

PURPOSE

The purpose of this study was to evaluate the stress distribution under various loading conditions within posterior metal-free crowns made of new composite materials.

MATERIALS AND METHODS

A three-dimensional finite element model representing a mandibular first molar was constructed. Variations of the model had crowns of two types of composite, a glass ceramic, and porcelain fused to metal. A load of 600 N, simulating the maximum bite force, was applied vertically to the crowns. Loads of 225 N, simulating masticatory force, were applied from three directions (vertically, at a 45-degree angle, and horizontally).

RESULTS

The stress distributions in both types of composite crown were similar to that of the glass-ceramic crown. In the test simulating maximum bite force, the maximum tensile stresses on all crowns (17.9 to 18.3 MPa) concentrated around the loading points. In the masticatory force-stimulation test, the specimens experienced maximum tensile stresses of 20.3 to 26.6 MPa under a horizontal load and 10.9 to 11.0 MPa under a vertical load. When the load was applied horizontally, the maximum tensile stress was observed around the loading points on the surface in the case of composite and glass-ceramic crowns, and in the cervical area of the metal coping in the porcelain-fused-to-metal crowns.

CONCLUSION

It would appear that the strength of occlusal contact points is important to the integrity of posterior metal-free crowns made of new composite materials and that bite forces applied from the horizontal direction are a critical factor determining success and failure.

A novel centrosomal ring-finger protein, dorfin, mediates ubiquitin ligase activity

We cloned a novel gene, Dorfin (double ring-finger protein), from human spinal cord. The Dorfin mRNA transcript was 4.4 kb and expressed ubiquitously in many organs as well as in the central nervous system, including the spinal cord. Dorfin encoded 838 amino acid protein Dorfin, which contains two RING-finger motifs and an IBR (in between RING-fingers) motif at its N-terminus. Dorfin is a short-lived protein. Treatment with MG132, a potent proteasome inhibitor, resulted in the accumulation of ubiquitinated Dorfin and Dorfin-associated cellular proteins in cultured cells. Dorfin bound specifically with human ubiquitin-conjugating enzymes UbcH7 and UbcH8 through the RING-finger/IBR domain. Partial deletion of the RING-finger/IBR domain eliminated these interaction and ubiquitination activities. These results strongly suggest that Dorfin is a new member of RING-finger type ubiquitin ligase. Dorfin is localized in the centrosome and probably functions in the microtubule organizing centers.

Two novel genes, human neugrin and mouse m-neugrin, are upregulated with neuronal differentiation in neuroblastoma cells

We herein report two new genes, human neugrin and mouse homologue m-neugrin, found by screening the cDNA library for the human spinal cord. The neugrin mRNA encodes 219 amino acids and its deduced amino acid sequence contains an NLS-like domain. No previously known motif is found in it. m-neugrin mRNA encodes 233 amino acids. Neugrin and m-Neugrin are 70% homologous in amino acid sequence. Northern analysis revealed that neugrin was strongly expressed in the heart, brain, and skeletal muscle, and m-neugrin in the liver, kidney, and brain. A transfection study indicated that these proteins are localized in the nucleus. Although the expression of neugrin was found to be ubiquitous in the nervous system, in situ hybridization showed that both neugrin and m-neugrin were expressed mainly in the neurons rather than the glial cells. Their expression was highly upregulated with the neurite outgrowth associated with neuronal differentiation in neuroblastoma cell lines. These results indicate that neugrin and m-neugrin are mainly expressed in neurons in the nervous system, and play an important role in the process of neuronal differentiation.

[Pure red cell aplasia induced by clomipramine hydrochloride in a patient with SLE]

A 48-year-old woman, who had been suffering from systemic lupus erythematosus (SLE), developed normochromic normocytic anemia after receiving clomipramine hydrochloride. Her reticulocyte count was low, and a bone marrow aspirate revealed erythroid hypoplasia without involvement of other cell lines. Thus a diagnosis of pure red cell aplasia (PRCA) was made. The anemia gradually resolved following withdrawal of the drug. Although several drugs are known to cause PRCA, this is the first time that clomipramine hydrochloride has been reported to have such an effect. The underlying SLE in this case suggested the possible immunological pathogenesis of drug-induced PRCA.

[Evaluation of a new method for antifungal drugs susceptibility testing to yeasts]

We compared the Etest with a broth microdilution method (FP panel), performed according to the National Committee for modified Clinical Laboratory Standards (NCCLS) document M27-P guidelines, for determining the MICs of 81 clinical isolates of yeasts (7 Candida albicans, 8 Candida glabrata, 10 Candida parapsilosis, 6 Pichia anomala, 10 Candida tropicalis, 4 Candida guilliermondii, 4 Candida krusei, 6 Trichosporon cutaneum, 5 Candida ciferrii, 3 Candida famata, 4 Candida norvegensis, 2 Rhodotorula rubra, 3 Candida lusitaniae, 2 Candida curvata, 1 Candida inconspicua, 1 Candida intermedia, 1 Candida colliculosa, 1 Cryptococcus spp, 1 Tricosporon capitatum, 1 Pichia ohmeri, 1 Saccharomyces cerevisiae). The Etest results for 6 ATCC standard strains correlated well with reference MICs except those of flucytosine (5-FC) for C. krusei, which tended to be 1 to 2 log2 dilution higher than the MIC range determined by NCCLS guidelines. However, the best agreement between the results for clinical isolates was seen with 5-FC (100% agreement [Within +/- 2 log2 dilutions] between the results of the two methods). There was a 91.4% agreement between the results of the two methods with amphotericin B (Etest MICs tended to be 1 to 2 log2 dilution lower than those of the FP panel). The Etest results with litraconazole for clinical isolates except C. tropicalis were similar to MICs of the FP panel (Etest for C. tropicalis showed 1 to 2 log2 dilution lower than FP panel). Also, the Etest results with fluconazole for clinical isolates except C. tropicalis were similar of 1 log2 dilution higher than MICs of the FP panel (Etest for C. tropicalis showed more than 2 log2 dilution lower than FP panel). These results showed a good level of overall agreement between the Etest method and the broth microdilution test (FP panel). Since the Etest is a less laborintensive and much simpler method, it appears to be a useful procedure for testing the susceptibility of yeasts to antifungal agents.

Significance of membrane type 1 matrix metalloproteinase expression in breast cancer

Expression of matrix metalloproteinases (MMPs) plays an essential role in tumor metastasis and invasion through the degradation of extracellular matrix (ECM). MT1-MMP (membrane type 1 matrix metalloproteinase), a membrane-type MMP, is responsible for the activation of MMP2. In this study the significance of MT1-MMP expression in human breast tumors was investigated by immunocytochemical assay, and its correlation with clinicobiological features was analyzed. MT1-MMP expression was detected in tumor cells and/or stromal cells, and there was a strong correlation between the expressions of MT1-MMP in the two cell types. Out of 183 primary tumors, 103 (56.2%) showed positive staining of MT1-MMP in tumor cells. MT1-MMP expression showed no significant correlation with any of the clinicobiological parameters examined, including hormone receptor status and angiogenesis. In postoperative survival analysis, MT1-MMP expression itself was not a significant prognostic factor. However, in the particular subgroup with the accumulation of thymidine phosphorylase (TP)-positive stromal cells, which have been activated by various stimuli, such as cytokines and hypoxia, MT1-MMP expression had a significant prognostic value. These data suggested that MT1-MMP might function cooperatively with tumor-associated stromal cells for the progression of breast cancer.

Metalloproteinases and tissue inhibitors of metalloproteinases

Because the proteolytic degradation of extracellular matrix is required for invasion and metastasis, it would appear that the important family of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) might be prognostic indicators of the invasive potential of a breast tumor. Nevertheless, there are few data demonstrating an independent prognostic value of any individual MMPs or TIMPs in primary breast cancer patients. It is possible, however, that the balance among levels of certain MMPs and their inhibitors will be more informative, since MMPs are clearly involved in paracrine tumor-stromal interactions and are associated with angiogenesis, which does appear to be prognostic.

Use of PCR serum in diagnosing and monitoring cytomegalovirus reactivation in bone marrow transplant recipients

We previously reported that the use of polymerase chain reaction (PCR) in detecting cytomegalovirus (CMV) DNA in serum (sPCR) enables the detection of CMV viremia, which has not been possible with other methods. In this study, the clinical usefulness of sPCR was investigated by comparison with the results of three other diagnostic methods, i.e., antigenemia assay (AG), shell vial culture test (shell vial), and complement-fixing (CF) antibody titer. The present study included 26 patients with hematological diseases who had undergone allogeneic bone marrow transplantation (BMT). A total of 347 samples were collected, and the results of the sPCR and AG methods were in agreement in 91.1% of the samples. When a subject was positive in both the sPCR and AG tests, and the other two tests (shell vial and CF) were also positive, CMV reactivation was surmised as definite. When only the result of the shell vial test or the CF test was positive, these results were taken as false-positives. The time at which the samples became positive in each of these four tests was 7.5 weeks post-BMT for sPCR, 7.0 weeks post-BMT for the AG test, 7.4 weeks post-BMT for the shell vial test, and 9.7 weeks post-BMT for the CF test. Thus, it was found that samples became positive at almost the same time for the sPCR, AG, and shell vial tests. Interstitial pneumonitis (IP) due to CMV developed in 3 subjects. These cases were positive in the sPCR, AG, and shell vial tests prior to the manifestation of symptoms of IP. The CF test did not become positive until after the onset of the disease. As the IP due to CMV was controlled with treatment, the sPCR and AG tests became negative. With the shell vial and CF tests, on the other hand, the test results continued to be positive even after the IP was cured. These findings demonstrate that the sPCR test method--like the AG test--yields few false-positive results. Therefore, the sPCR method is useful in early diagnosis of reactivation of CMV and for evaluation of the efficacy of therapy administered for IP. In addition, sPCR can be performed simultaneously on a large number of samples, and the evaluation of the test results is simple. We conclude that the sPCR test may be superior to the three other diagnostic methods for evaluation of serum samples from multiple institutions.