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Objectives: The study investigated the influence of retention grooves and material thickness of the retainer wing on the retentive strength of resin-bonded attachments (RBAs)., Materials and Methods: Sixty-four extracted human molars were used. Each tooth received a preparation limited to the enamel for the retainer wings of the RBAs. The specimens were divided into eight groups, each containing eight specimens. The groups varied based on the number of conical retention grooves (0, 1, 2, or 4) and the thickness of the CoCr retainer wings (0.4 mm and 0.8 mm). Before testing the retentive strength of the RBAs, the specimens underwent 37,500 thermal cycles followed by dynamic loading of 1,200,000 cycles on the RBAs' patrices using a chewing simulator. The debonding test was conducted using a universal testing machine at a crosshead speed of 2 mm/min., Results: The mean retentive strength ranged from 326 ± 96 N to 440 ± 77 N. Only a small portion of specimens (10.9%) exhibited adhesive failure, while the remainder demonstrated cohesive failure within the tooth structure. Neither the number of retention grooves, the thickness of the retainer wings, nor the size of the bonding surface significantly affected retentive strength., Conclusions: The findings suggest that reducing the number of retention grooves and the material thickness does not influence the retentive strength of RBAs., Clinical Relevance: The retention of RBAs appears promising, supporting the clinical application of this treatment modality., (© 2024. The Author(s).)

Objectives: Single midline implants in the edentulous mandible can be used to support existing complete dentures to improve patients' satisfaction and masticatory efficiency. The impact on patients' dietary habits and the influence of the loading protocol of the implants was the subject of this study., Materials and Methods: In this prospective randomized clinical trial, edentulous patients with existing complete dentures in both jaws were treated with a single midline implant in the mandible. In group A, the implants were loaded immediately, in group B the loading was delayed after three months. Patients were asked to report on their nutritional intake before implant placement and 12, 24 and 60 months after loading using a standardized two-part questionnaire., Results: Nutritional intake regarding the frequency of consumption of the requested food items did not change significantly during the 60-months study period, regardless of the loading protocol. In contrast, the second part of the questionnaire revealed that after 60 months, there was a significant decrease in avoidance of food, that had a coarse and hard texture in both groups. This significant decrease was observable in the group A in the first 12 and 24 months and in the group B after 60 months., Conclusion: A change in the patients' dietary habits due to the insertion of a single midline implant in the mandible to support the existing complete denture cannot be observed, independently to the loading protocol., Clinical Relevance: Improving the chewing efficiency by single midline implants in the edentulous mandible does not lead to a change in dietary habits., (© 2024. The Author(s).)

Introduction: A recent study reported a 34% mid-term revision rate after M6-C™ cervical total disc replacement (CTDR) for wear-related osteolysis. Here, we aim to investigate the prevalence, risk factors, and radiographic characteristics of periprosthetic bony changes and implant failure of the M6-C™ artificial disc., Methods: We retrospectively analysed radiographic (conventional X-ray, CT scan) and clinical outcomes (EQ-5D-5L, Neck Disability Index (NDI), and Visual Analog Scale (VAS) for neck and arm pain) data collected during routine follow-up of patients who underwent CTDR with the M6-C™ between 2011 and 2015., Results: In total, 85 patients underwent CTDR with the M6-C™. Follow-up data were available for 43 patients (54% female, mean age 44 years) with 50 implants and a mean follow-up of 8.1 years (6.5-11 years). Implant failure with the presence of severe osteolysis was identified in 5 (12%) patients who were all male (p = 0.016) and implanted at the C5/6 level (p = 0.11). All failed implants required revision surgery. The overall prevalence of osteolysis was 44% (22/50 implants) and 34% (17/50 implants) for significant heterotopic ossification. Patients with high-grade osteolysis showed higher VAS arm pain (p = 0.05) and lower EQ-5D-VAS health VAS (p = 0.03)., Conclusion: We report a lower reoperation rate for failed M6-C™ implants than previously published, but confirmed that osteolysis and heterotopic ossification are common following CTDR with the M6-C™ and may be asymptomatic. Therefore, we strongly recommend ongoing clinical and radiographic monitoring after CTDR with the M6-C™, particularly for male patients implanted at the C5/6 level., (© 2024. The Author(s).)

Objectives: The aim of this study is to analyze the esthetic perception of selected canine features, namely crown length, shade, inclination, and angle of incisal edge tip., Materials and Methods: The anterior maxillary teeth of a Central European woman were photographed and digitally modified in order to investigate esthetic perceptions of the above four categories. Three groups of examiners with different levels of experience in the field of dentistry (laypersons/inexperienced dental students, advanced dental students, dentists) evaluated the photographs twice with the help of visual analogue scales., Results: The best-evaluated canines have approximately the same length as the central incisor, have the same shade as the other anterior teeth, are best embedded in a lighter overall tooth shade, are neutral to slightly palatal inclined, and have a right angled to rounded incisal edge (≥ 90°). The canines evaluated as least esthetic, however, are longer than the central incisors, darker, inclined labially, and have a tapered incisal edge. No significant differences could be found between the evaluations of the groups with regard to the four feature categories., Conclusions: Laypersons, advanced dental students, and dentists generally evaluate according to the same esthetic standards. Gender does not have a significant influence on evaluation. Clear definitions of esthetically favored shades, incisal edge shapes, inclination, and lengths of the canines can be given., Clinical Relevance: Since the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry, knowledge of the esthetically preferred morphology of canines is essential., Clinical Significance: The aim of this study is to give clear definitions of esthetically favored shades, incisal edge shapes, and lengths of the canines, as the esthetics of the smile line play a critical role for patients, dentists, dental technicians, and their supplying industry (e.g., denture tooth manufacturers). Precise knowledge of esthetic preferences is important in clinical practice for both dentists and dental technicians, for example, in order to adequately advise patients regarding esthetic corrections. Also, in the case of missing teeth, this knowledge is essential for optimal and satisfactory restorations. Thus, this study can contribute to the satisfaction of general practitioners and patients., (© 2022. The Author(s).)

Objectives: The aim of this study is to investigate vascular and neurosensory complications in edentulous patients following the installation of mandibular midline single implants in relation to lingual canals., Materials and Methods: After performing a cone beam computed tomography scan for the 50 recruited patients, the relationship between the potential implant site and the lingual canals was assessed, and all vascular and neurosensory complications were recorded., Results: Six patients (12%) reported profuse bleeding during implant placement, and 13 (26%) reported transient neurosensory changes, which were resolved after 3 months. According to the virtual implant planning, 44 patients (88%) would have their implants touching the lingual canals, six of them reported vascular changes (14%), and 12 out of 44 patients reported neurosensory changes (27%). For the six patients who would have their implants not touching the lingual canals, one patient reported transient neurosensory changes., Conclusions: The mandibular lingual canals are constant anatomic landmarks. Injury to the supra-spinosum lingual canals may occur during midline implant placement, depending on the implant length and the bone height., Clinical Relevance: Despite that injury to the supra-spinosum lingual canals during implant insertion does not result in permanent vascular or neurosensory complications, caution is required to avoid the perforation of the lingual cortices., (© 2022. The Author(s).)

Radiofrequency denervation has been established for many years as an important minimally invasive procedure for the treatment of chronic pain conditions. Positive experiences of many users for various indications are contrasted by a nonuniform evidence. With meticulous patient selection and correct assessment of the indications a longer term reduction of pain, a reduced need for analgesics and an improvement in the quality of life can be achieved. The aim of this interdisciplinary position paper is to present the value of radiofrequency denervation in the treatment of chronic pain. The summarized recommendations of the expert group are based on the available evidence and on the clinical experiences of Austrian centers that frequently implement the procedure. The position paper contains recommendations on patient selection and proven indications. We discribe safety aspects, complications, side effects and contraindications.

Objectives: The study evaluated the influence of the number of retention grooves and the retainer wing thickness on the retention of resin-bonded attachments (RBAs)., Methods: Overall, 64 extracted human teeth were prepared, whereby the number of retention grooves (4, 2, 1, or no grooves) and the material thickness (0.7 or 0.5 mm) of the RBAs were varied. This resulted in eight groups with eight specimens each. A sample size of eight specimens per group was chosen because the chewing simulator used for dynamic loading can load eight specimens at a time. After the size of the adhesive area was determined, the abutment teeth were provided with RBAs and subjected to a dynamic loading with thermal cycling. Finally, the failure load was examined using a retention test., Results: The mean failure loads ranged from 152 ± 50 N to 228 ± 32 N. There had been a significant interaction between the two main factors, i.e., number of retention grooves and material thickness. Neither the number of retention grooves nor the size of the adhesive area had a significant influence on the failure load., Conclusions: Using a reduced number of retention grooves seems reasonable. However, clinical considerations suggest using two retention grooves to simplify the preparation and bonding procedures., Clinical Relevance: The retention of resin-bonded attachments is promising and supports the clinical application of this minimally invasive treatment modality.

The corona pandemic has led to a number of restrictions and prohibitions, which in turn place large psychosocial or spiritual burdens on patients with COVID-19, their families and relatives and the treating personnel in the healthcare system. Patients with COVID-19 are not allowed to receive visitors and many hospitals and nursing homes have completely banned visitors. Many support services have been reduced or stopped completely. Necessary treatment interventions for other patients with critical and life-limiting diseases have been delayed or suspended in order to free resources for the expected COVID-19 patients; however, these people need to feel social connectedness with their relatives. Palliative care patients should be exempted from any ban on visitors. Families should be able to visit dying patients even on intensive care units or isolation wards, using adequate protective equipment. Alternative options, such as video telephone calls or via social media should be explored for patients in isolation. Families should also be enabled to say goodbye to the deceased with adequate protective equipment or should be offered alternative real or virtual options for remembrance and commemoration. Health care professionals coping with the exceptional stress should be continuously supported. This requires clear communication and leadership structures, communication training, psychosocial support, but most of all optimal framework conditions for the clinical work.

Objectives: The knowledge about the influence of dental treatment on health-related quality of life (HRQoL) is still limited. The aim of this multicenter randomized controlled clinical trial was to assess the effect of stabilizing an existing complete denture, by means of a single mandibular implant, on HRQoL. Furthermore, the impact of the loading protocol, i.e., immediate or delayed loading, in edentulous patients was evaluated., Methods: One hundred fifty-eight participants aged 60-89 years were randomly assigned to study group A (immediate loading; n = 81) and to group B (delayed loading; n = 78). All participants received a single midline implant in the mandible. The implants were either immediately loaded (group A) or after a closed healing period of 3 months (group B) by connecting the existing mandibular complete dentures to ball attachments. HRQoL was assessed with the Short Form-36 questionnaire of health (SF-36) at baseline, 4 months, and 24 months after implant loading., Results: Improvement of HRQoL by means of a single implant-retained mandibular overdenture could not be demonstrated after 4 and 24 months of implant loading. Furthermore, the application of two different loading protocols did not influence HRQoL ratings of study participants., Conclusion: The loading protocol is not a factor, influencing HRQoL in patients treated by a single midline implant in the edentulous mandible., Clinical Relevance: A single midline implant in the edentulous mandible, stabilizing a mandibular complete denture, cannot be recommended for improving HRQoL.

Objectives: The aim of this in vitro study was to assess changes in the gene expression of proinflammatory cytokines in human whole blood after contact with titanium implant surfaces conditioned by UV light. To this end, expression levels of proinflammatory cytokines were analyzed in vitro in human whole blood., Materials and Methods: Dental implants made of grade 4 titanium were conditioned by UV light in a UV device and submerged in human whole blood. Unconditioned implants served as controls, and blood samples without implants served as the negative control group. Sampling was performed at 1, 8, and 24 h. Changes in the expression levels of interleukin-1β (IL1B) and tumor necrosis factor alpha (TNF) were assessed using RT-qPCR at the mRNA level., Results: The gene expression of IL1B was significantly suppressed in the test group over the observation period compared to the control group during the 1-8 h after having contact between the implant surface and the blood. The gene expression of TNF was not significantly altered by UV conditioning after 1 and 8 h of observation, but both cytokine expression levels were increased significantly after 24 h., Conclusions: Differences in the gene expression of proinflammatory cytokines after insertion of UV-conditioned titanium implants can be assessed using a human whole blood test. UV-conditioned implant surfaces apparently suppress the release of IL1B in vitro., Clinical Relevance: The results of our publication demonstrate that modulation of the early inflammatory response in human whole blood is possible by surface treatment with UV light. In particular, the suppression of IL1B expression, especially after the initial contact of blood cells, may be beneficial in the osseointegration of titanium implants by positively influence the balance between rejection and acceptance of an implant.

Patients with opioid use disorder survive longer and reach higher ages due to harm reduction and maintenance programs. Therefor and because of concomitant comorbidities there is an increased incidence of life-limiting diseases. Thus, increasing numbers of patients with opioid use disorder or in maintenance programs will require palliative care. However, both inpatient and outpatient service providers are uncertain about providing palliative care for these patients. Home-care teams and inpatient hospices have been known to refuse admission for patients with opioid use disorder. Providing medical care to patients receiving substitution therapy can be challenging because maintenance programs require strict compliance with their rules and regulations; however, an individualized approach with knowledge of basic legal requirements enables good palliative care. In this manner, it is possible to ensure healthcare for these aging patients.

Objectives: The purpose of this laboratory study was to evaluate the influence of the attachment design and material on the retention of resin-bonded attachments (RBAs) before and after dynamic loading., Materials and Methods: Forty-eight caries-free human premolars were prepared for RBAs fabricated either from a CoCr alloy or from zirconia ceramic. Specimens were divided into three groups (n = 16 each). Two groups had a standard attachment design for alloys (group M made from a CoCr alloy and group Z1 made from zirconia ceramic). The third group had an attachment design optimized for zirconia ceramic (group Z2 made from zirconia ceramic). Attachments were bonded to the acid-etched enamel of the premolars using a phosphate monomer containing adhesive resin. Subgroups of eight specimens each were either debonded using a tensile force in a universal testing machine at a cross-head speed of 2 mm/min (S) or were exposed to dynamic loading with 50 N over 1200,000 loading cycles in a chewing simulator prior to debonding (D)., Results: There were no significant differences in the initial failure loads of groups. With the exception of subgroup Z1-D, all specimens survived the dynamic loading. Statistical analysis showed that dynamic loading caused a significant decrease of failure loads in group Z1. In contrast, subgroup Z2-D exhibited significantly higher failure loads compared to the subgroup Z1-D., Conclusions: The results suggest that zirconia RBAs fabricated with an optimized attachment design may be a valid clinical alternative to metal RBAs., Clinical Relevance: Clinical data on the long-term potential of zirconia RBAs is required before these restorations can be recommended for general use.

Objectives: Being a secondary outcome in a multicenter randomized controlled trial, the present analysis focused on interdental spacing in the shortened dental arch (SDA). The aim was to evaluate changes in interdental spacing in dependence of two different treatments after an observation period of up to 5 years., Material and Methods: Patients were either treated with a partial removable dental prosthesis (PRDP) for molar replacement (PRDP group) or according to the SDA concept aiming at a premolar occlusion (SDA group) in a randomized manner. Interdental spacing in the anterior region was measured with gauges and categorized as "0" (<0.1 mm), "1" (<0.5 mm), "2" (0.5-1 mm), and "3" (>1 mm). The statistical analysis was performed with analysis of variance models followed by linear contrast., Results: Ninety-one patients (SDA n = 41, PRDP n = 50) were included. Changes of interdental spacing were detected in 70.7 % of all cases. A significant difference between the mean score changes was found in the mandible comparing the PRDP group and the SDA group. The respective mean score changes from baseline to 5 years were 0.23 (SD 0.49) for the PRDP group and 0.02 (SD 0.30) for the SDA group (p = 0.023)., Conclusions: Major interdental spacing could be observed in neither of the groups. The SDA concept resulted in a slightly better outcome., Clinical Relevance: When deciding whether to replace missing molars, the present results give further support to the SDA concept.

Objectives: The present systematic review compared the effectiveness of soft tissue substitutes (STSs) and autogenous free gingival grafts (FGGs) in non-root-coverage procedures to increase keratinized tissue (KT) width around teeth., Materials and Methods: Included studies fulfilled the following main eligibility criteria: (a) preclinical in vivo or human controlled trials using FGG as control, (b) non-root-coverage procedures, and (c) assessment of KT width. Meta-analysis was performed on the gain in KT width (primary outcome variable) and several secondary variables., Results: Eight human trials with short observation time evaluating five different STSs were identified. FGG yielded consistently significantly (p < 0.001) larger increase in KT width irrespective whether the comparison regarded an acellular matrix or a tissue-engineered STS. Further, FGG yielded consistently ≥2 mm KT width postoperatively, while use of STS did not, in the few studies reporting on this outcome. On the other hand, STSs resulted in significantly better aesthetic outcomes and received greater patient preference (p < 0.001)., Conclusions: Based on relatively limited evidence, in non-root-coverage procedures, FGG (1) resulted consistently in significantly larger increase in KT width compared to STS and (2) yielded consistently ≥2 mm KT width postoperatively, while STSs did not. STSs yielded significantly better aesthetic outcomes, received greater patient preference, and appeared safe., Clinical Relevance: Larger and more predictable increase in KT width is achieved with FGG, but STSs may be considered when aesthetics is important. Clinical studies reporting relevant posttreatment outcomes, e.g., postop KT width ≥2 mm, on the long-term (>6 months) are warranted.

Objectives: This randomized clinical trial compares immediate and delayed loading of single implants to support mandibular overdentures. The aim of this preliminary analysis is to test the hypothesis whether patients with immediate loading will experience less pain and discomfort through the intervention than patients with delayed loading., Materials and Methods: Edentulous patients in nine German dental schools received a midline implant with a length of 11 mm. Implants with a minimum insertion torque of 30 Ncm and an implant stability quotient of ≥60 were randomly allocated to group A for immediate loading using ball attachments or to group B for delayed loading after 3 months. Patients completed questionnaires with 100-mm visual analogue scales about the items pain, pain during chewing, swelling, bleeding, and perception of the intervention at the day of surgery and 1, 2, 3, and 7 days, thereafter. Groups were compared by Wilcoxon-Mann-Whitney tests (P ≤ 0.05)., Results: The questionnaires of 81 patients in group A and 74 patients in group B were completed. The medians for pain and discomfort were moderate (<30). Participants of group A felt significantly more pain from the first day and more swelling from the third day after implantation than participants of group B. The individual perception of interventions showed no significant differences between groups., Conclusions: Immediate loading evoked more postoperative pain and swelling than the two stages of delayed loading., Clinical Relevance: Immediate loading of a single mandibular midline implant supporting overdentures should be carefully considered.

Objective: The aim of this within-subject study was to evaluate the outcome with implant-tooth-supported removable partial dental prostheses (RPDP group) and implant-supported removable complete dental prostheses (edentulous group) in terms of masticatory performance and self-assessment., Materials and Methods: Thirty patients participated in this prospective clinical study (RPDP group: n = 12; edentulous group: n = 18). The prostheses were supported in strategically advantageous regions by placing implants with ball attachments and corresponding matrices in the existing dentures. The masticatory performance was evaluated with the Swallowing Threshold Test Index (STTI), the number of chewing strokes, and the time needed until swallowing at pre-treatment and 6 weeks after integration of ball attachments. Additionally, patients scored chewing satisfaction before and after implantation on a visual analogue scale., Results: The STTI increased significantly (p ≤ 0.05) after implant therapy in the edentulous group but not in the RPDP group. Furthermore, the STTI was significantly higher (p ≤ 0.05) in the RPDP group than in the edentulous group at pre-treatment, however, not after therapy (P > 0.05). All patients were very satisfied after therapy concerning ability of speaking, chewing, and stability of their prosthesis., Conclusions: Patients of the edentulous group benefit more from strategically placed implants under the existing dentures than patients from the RPDP group. However, according to the subjective assessment, the chewing satisfaction generally increased for both groups after implant therapy., Clinical Relevance: Patients with a strongly reduced dentition and edentulous patients benefit from strategically placed implants under the existing removable dentures.

Objectives: The objective of the study is to evaluate practices of dentists regarding adhesive cementation of all-ceramic restorations over a period of 8 years., Materials and Methods: The authors developed a questionnaire regarding adhesive cementation procedures for all-ceramic restorations. Restorations were distinguished between made out of silicate ceramic or oxide ceramic. The questionnaire was handed out to all dentists participating in a local annual dental meeting in Northern Germany. The returned questionnaires were analyzed to identify incorrect cementation procedures based upon current evidence-based technique from the scientific dental literature. The survey was conducted three times in 2007, 2011, and 2015 and their results were compared., Results: For silicate ceramic restorations, 38-69 % of the participants used evidence-based bonding procedures; most of the incorrect bonding methods did not use a silane containing primer. In case of oxide ceramic restorations, most participants did not use air-abrasion prior to bonding. Only a relatively low rate (7-14 %) of dentists used evidence-based dental techniques for bonding oxide ceramics., Conclusion: In adhesive cementation of all-ceramic restorations, the practices of surveyed dentists in Northern Germany revealed high rates of incorrect bonding. During the observation period, the values of evidence-based bonding procedures for oxide ceramics improved while the values for silicate ceramics declined. Based on these results, some survey participants need additional education for adhesive techniques., Clinical Relevance: Neglecting scientifically accepted methods for adhesive cementation of all-ceramic restorations may result in reduced longevity of all-ceramic restorations.

Objectives: The aim of this multi-center, randomized controlled trial was to assess the impact of missing posterior support on the risk for temporomandibular disorder (TMD) pain by comparing patients with either shortened dental arches (SDA) or molar replacement by removable dental prostheses (RDP)., Methods: A sample of 215 patients with bilateral molar loss in at least one jaw was consecutively recruited in 14 prosthodontic departments of dental schools in Germany. Of the initial sample, 152 patients (mean age: 59.7 years; 53.9 % female) received randomly allocated interventions (SDA: n = 71; RDP: n = 81). Presence of TMD pain was assessed using patients' self-reports and was verified by physical examination and by pain intensity, as the mean of current pain, worst pain, and average pain in the last 6 months, with 10-point ordinal rating scales. Assessments were performed before treatment and at follow-ups until 60 months after treatment. Impact of interventions on TMD risk and pain intensity was computed by applying logistic and linear random-intercept models., Results: Tooth replacement (RDP) did not significantly change the risk for self-reported (odds ratio [OR]: 1.1; confidence interval [CI]: 0.4 to 3.4) or clinically verified (OR: 0.7; CI: 0.1 to 4.3) TMD pain compared to no tooth replacement (SDA). Mean characteristic pain intensity was virtually identical in both groups (Coeff: 0.01; CI: -0.30 to 0.32)., Conclusion: Retaining or preservation of an SDA is not a major risk factor for TMD pain over the course of 5 years when compared to molar replacement with RPDs., Clinical Relevance: Seemingly, missing molars do not have to be replaced in order to prevent TMD pain.

Objectives: The concept of a single midline implant retaining a complete mandibular denture is controversially discussed among experts. Studies are rare in the literature, and commonly accepted recommendations for this treatment options are not available. This systematic literature review was performed to give an overview over the current literature on the single midline implant therapy for the edentulous mandible and to reveal whether this treatment option might be an alternative to commonly accepted treatment modalities with more implants., Methods: A review of the literature published until 24th of May 2013 was conducted to identify in vivo studies on the single midline implant concept with a mean follow-up time of at least 3 months., Results: From the electronic search, 11 studies were finally included. After an observation period of 3-60 months, the implant survival rate ranged from 62.5 to 100 %. The most frequent prosthetic maintenance intervention was "activation of the matrix" followed by "repair of fractured denture base.", Conclusions: The concept of one single midline implant to retain a mandibular complete denture can be an alternative, especially for elderly patients. Immediate loading of the implants should be avoided, and the way of integrating the matrix into the denture base should be carefully considered.

Introduction: Zirconia posts can be used as an esthetic alternative to metal posts. Despite their advantages, there is a lack of information about the long-term performance of zirconia posts., Objectives: This retrospective clinical study examined the survival probability, clinical performance, and reasons for failure of teeth restored with zirconia posts after an observation period of up to 10 years., Materials and Methods: After a mean observation period of 10 years, clinical and radiographic examinations were carried out for a total of 64 posts in 45 patients. The posts received mainly either ceramic or direct composite buildups. All posts were adhesively cemented, after air abrasion with alumina particles or silica coating and silanization. The majority of the reconstructed teeth were used as abutments for metal ceramic or ceramic fixed dental prostheses. Kaplan-Meier analysis was employed to compute the survival probability of teeth restored with zirconia posts. Cox regression analysis was used to assess the risk of failure and to identify possible covariates., Results: During the follow-up period, a drop-out rate of 49.4 % was recorded. The survival probability for teeth with zirconia posts was 81.3 % after 10 years., Conclusion: Within the limits of this study, zirconia posts can be used for abutments that will be restored with ceramic restorations. However, due to the high patient drop-out rate, careful interpretation of the current results is suggested., Clinical Relevance: The present paper is the first 10-year clinical study on teeth restored with zirconia posts and could serve as a reference for future research. In addition, it provides long-term data about restorations already implemented by dental practitioners.

Objectives: Although the shortened dental arch (SDA) concept is a widely accepted strategy to avoid overtreatment, little is known on its impact on oral health-related quality of life (OHRQoL). This multicenter randomized controlled trial aimed to investigate the OHRQoL for removable partial dental prostheses (RPDP) with molar replacement versus the SDA concept., Material and Methods: In both groups, missing anterior teeth were replaced with fixed dental prosthesis. Two hundred fifteen patients with bilateral molar loss in at least one jaw were included. The Oral Health Impact Profile (OHIP-49) was completed before; 6 weeks (baseline), 6 months, and 12 months after treatment; and thereafter annually until 5 years., Results: Of the initial cohort, 81 patients were assigned to the RPDP group and 71 to the SDA group (age, 34 to 86 years). Before treatment, the median OHIP score was similar in both groups (RPDP, 38.0; SDA, 40.0; n.s.). Results indicate marked improvements in OHRQoL in both groups between pretreatment and baseline (RPDP, 27.0; SDA, 19.0; p ≤ 0.0001) which continued in the RPDP group until the 1-year follow-up (p = 0.0002). These significant reductions in OHIP scores are reflected in its subscales. No further differences were seen within and between groups during the remainder observation period., Conclusion: Both treatments show a significant improvement in OHRQoL which continued in the RPDP group until the 1-year follow-up. No significant differences were seen between groups., Clinical Relevance: For improving OHRQoL, it is not necessary to replace missing molars with a RPDP.

Objective: Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing., Materials and Methods: Ten patients (six men and four women; average age = 66.7 years; age range = 58-78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing., Results: Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples., Conclusions: Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci., Clinical Relevance: These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities.

Objective: The aim of this in vitro study was to assess lipopolysaccharide microleakage at conical implant-abutment connections of two-piece dental implants in terms of the expression levels of genes involved in lipopolysaccharide-mediated proinflammatory cytokine production., Materials and Methods: Two implant systems with conical implant-abutment connections were inoculated with lipopolysaccharide and submerged in human whole blood. Positive-control blood samples (without implants) were stimulated with 4 μg/ml, 2 μg/ml, 200 ng/ml, and 20 ng/ml lipopolysaccharide. Sampling was performed after 1, 8, and 24 h of incubation. Changes of gene expression levels of Toll-like receptor 9, tumor necrosis factor-α, nuclear factor kappa light chain enhancer of activated B cells, interleukin-1β, and interferon-γ were assessed by real-time quantitative PCR. In addition, protein expression levels of interleukin-6, tumor necrosis factor-α, interleukin-1β, and interferon-γ were determined by immunoassay., Results: Changes in cytokine expression at the genomic and proteomic levels indicated lipopolysaccharide leakage at the interfaces of both tested implant systems, although some implants showed no sign of microleakage. Any tested concentration of lipopolysaccharide stimulated similar gene expression., Conclusions: Conical implant-abutment connections of two-piece dental implants do not prevent microleakage on a molecular level. Changes in lipopolysaccharide-induced proinflammatory cytokine gene expression facilitate the detection of lipopolysaccharide microleakage at implant-abutment interfaces., Clinical Relevance: Small amounts of lipopolysaccharide released from intra-implant cavities can stimulate a detectable immunological response in human whole blood and may induce alveolar bone resorption via the osteoclast-activating pathway.

Transmembrane protein transporters possessing binding sites for ions, toxins, pharmaceutical drugs, and other molecules constitute excellent candidates for developing sensitive and selective biosensing devices. Their attractiveness for analytical purposes is enhanced by the intrinsic amplification capabilities shown when the binding event leads to major changes in the transportation of ions or molecules other than the analyte itself. The large-scale implementation of such transmembrane proteins in biosensing devices is limited by the difficulties encountered in inserting functional transporters into artificial bilayer lipid membranes and by the limitations in understanding and exploiting the changes induced by the interaction with the analyte for sensing purposes. Here, we show that lysenin, a pore-forming toxin extracted from earthworm Eisenia foetida, which inserts stable and large conductance channels into artificial bilayer lipid membranes, functions as a multivalent ion-sensing device. The analytical response consists of concentration and ionic-species-dependent macroscopic conductance inhibition most probably linked to a ligand-induced gating mechanism. Multivalent ion removal by chelation or precipitation restores, in most cases, the initial conductance and demonstrates reversibility. Changes in lipid bilayer membrane compositions leading to the absence of voltage-induced gating do not affect the analytical response to multivalent ions. Microscopic current analysis performed on individual lysenin channels in the presence of Cu(2+) revealed complex open-closed transitions characterized by unstable intermediate sub-conducting states. Lysenin channels provide an analytical tool with a built-in sensing mechanism for inorganic and organic multivalent ions, and the excellent stability in an artificial environment recommend lysenin as a potential candidate for single-molecule detection and analysis.

The aim of this study was to evaluate the microstructural quality of noble alloy castings from commercial dental laboratories using the wiping-etching method as a simple method for quality control. In total, 240 castings from two noble alloys (AuAgCuPt and AuPtZn) were taken from a day's production of five different dental laboratories. The casting quality was evaluated by determining the grain size and by assessing the number and size of shrinkage cavities after acidic etching of the alloy surfaces. The AuAgCuPt alloy castings showed an acceptable quality in the microstructural analysis. The results of AuPtZn castings, however, were not satisfactory because 50.8% of the samples showed a remarkably poorer quality compared to the specifications made by the manufacturer. The proportion of the employed reclaimed alloy had no influence on the casting quality when AuAgCuPt alloy was used, but was influential when casting restorations with AuPtZn alloy. When determining the quantity and size of shrinkage cavities, none of the evaluated castings was of such a poor quality that a replacement of the castings had to be considered. The differences in grain size and quantity of shrinkage cavities were reflecting the individual laboratory process rather than the admixture of new/reclaimed alloy. The presented analysis can be used as a simple method for quality control of dental castings.

The purpose of this study was to compare the patients' and dentists' perception of dental appearance. Based on internationally accepted guidelines about dental esthetics, a questionnaire was developed to measure "dental appearance" (QDA). Eleven items defined a QDA sum score (0 = "absolutely satisfied", 44 = "absolutely dissatisfied"). The QDA was completed by 16 patients (eight women, eight men, mean age 63 ± 9 years) before and after a complete oral rehabilitation. Forty-two dentists evaluated the esthetics before and after rehabilitation on a visual analog scale (VAS, 0 = "absolutely unesthetic", 100 = "absolutely esthetic"). The patients' quoting showed a significant esthetic improvement (QDA sum score) from 22 before treatment to 3.5 after treatment (P ≤ 0.001). Although most of the dentists judged an improvement in most of the patients dental appearances, no significant correlation could be found between patients' and dentists' judgment regarding dental appearance (r = -0.13-0.53, P > 0.05). When evaluating the influence of age, gender, and experience on rating dental appearance, no significant differences (P > 0.05) could be found.

Microleakage has been discussed as a major contributing factor for inflammatory reactions at the implant-abutment connection. In previous studies, the tightness against corpuscular bodies (viable bacteria) has been successfully investigated under static and dynamic conditions. The aim of this study was to investigate the tightness against endotoxins of two implant systems (AstraTech and Ankylos) with conical internal connections under static conditions. The inner parts of eight implants of each system were inoculated with endotoxin. Implants were screwed together with the respective abutments and stored under isostatic conditions in a supernatant of pyrogen-free water for 168 h. Supernatant samples were taken after 5 min, 24 h, 72 h, and 168 h, and endotoxin contamination was determined by the amebocyte-lysate test. Only one implant in the AstraTech group showed no sign of endotoxin contamination after 168 h, while the other implants showed contamination after varying storage times, respectively. The implants in the Ankylos group showed endotoxin contamination after only 5 min of storage in the supernatant solution. The tested internal conical implant-abutment connections appear to be unable to prevent endotoxin leakage. In average, Astra implants showed a higher tightness than Ankylos implants.

Purpose: The inducible enzyme cyclooxygenase-2 (COX-2) catalyzes PGE(2) production and plays an important role in the progression of many solid cancers. However, the role of COX-2 expression in cervical lymph node metastases of head and neck cancer has not been clarified yet., Patient and Methods: We comment on a male patient aged 53 who was admitted to an ENT-department with acute bleeding from an advanced hypopharyngeal carcinoma and a frontotemporal mass. Prior to palliative intended radiotherapy, the metastasis was resected. During the procedure, a small amount of tumor tissue was harvested for primary tumor cell culture., Results: COX-2 overexpression was demonstrated in the primary tumor tissue, the metastasis, in the cultured tumor cells by standard immunohistochemistry, as well as cytochemistry., Conclusions: A simultaneous expression of COX-2 in head and neck carcinoma was presented for the first time. Besides the prognostic impact in oral carcinogenesis, this COX-2 role of biomarker for aggressive head and neck squamous cell carcinomas should be further evaluated. Additionally, treatment of hypopharyngeal carcinomas with selective COX-2 inhibitors could be beneficial when administered in combination with radiochemotherapy.

Seven institutions participated in this small clinical trial that included 19 patients who exhibited oropharyngeal dysphagia on videofluorography (VFG) involving the upper esophageal sphincter (UES) and who had a 3-month history of aspiration. All patients were randomized to either traditional swallowing therapy or the Shaker exercise for 6 weeks. Each patient received a modified barium swallow pre- and post-therapy, including two swallows each of 3 ml and 5 ml liquid barium and 3 ml barium pudding. Each videofluorographic study was sent to a central laboratory and digitized in order to measure hyoid and larynx movement as well as UES opening. Fourteen patients received both pre-and post-therapy VFG studies. There was significantly less aspiration post-therapy in patients in the Shaker group. Residue in the various oral and pharyngeal locations did not differ between the groups. With traditional therapy, there were several significant increases from pre- to post-therapy, including superior laryngeal movement and superior hyoid movement on 3-ml pudding swallows and anterior laryngeal movement on 3-ml liquid boluses, indicating significant improvement in swallowing physiology. After both types of therapy there is a significant increase in UES opening width on 3-ml paste swallows.