DIGITAL DENTISTRY AND ITS IMPACT ON ORAL HEALTH-RELATED QUALITY OF LIFE.

Over the past 50 years, digitization has gradually taken root in dentistry, starting with computer tomography in the 1970s. The most disruptive events in digital dentistry were the introduction of digital workflow and computer-aided manufacturing, which made new procedures and materials available for dental use. While the conventional lab-based workflow requires light or chemical curing under inconsistent and suboptimal conditions, computer-aided manufacturing allows for industrial-grade material, ensuring consistently high material quality. In addition, many other innovative, less disruptive, but relevant approaches have been developed in digital dentistry. These will have or already impact prevention, diagnosis, and therapy, thus impacting patients' oral health and, consequently, their oral health-related quality of life. Both software and hardware approaches attempt to maintain, restore, or optimize a patient's perceived oral health. This article outlines innovations in dentistry and their potential impact on patients' oral health-related quality of life in prevention and therapy. Furthermore, possible future developments and their potential implications are characterized.

Modern Polymers for Dental Application.

Ceramics dominate clinical procedures in modern dentistry related to the artificial replacement of teeth with fixed dental prostheses, replacing metal-based frameworks on a large scale [...].

Sex hormones associated with temporomandibular pain on palpation in male adolescents-Results of the epidemiologic LIFE child study.

OBJECTIVE: This study aimed to investigate whether the sex steroid precursor hormone dehydroepiandrosterone sulphate (DHEA-S), sex hormone-binding globulin (SHBG) and testosterone (TT) are associated with temporomandibular (TM) pain on palpation in male adolescents. METHODS: Out of the LIFE Child study dataset containing 1022 children and adolescents aged 10-18 years (496 males, 48.5%), we used a subsample of 273 male adolescents (mean age: 13.8 ± 2.3 years) in advanced pubertal development (PD) to analyse the association between hormones and TM pain. The Tanner scale was applied to describe the stage of PD. Pain on palpation of the temporalis and masseter muscles and the TM joints (palpation pain) was assessed using the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Serum levels of sex hormones (DHEA-S, SHBG and TT) were determined using standardised laboratory analyses. Free TT was estimated from the ratio between TT and SHBG (free androgen index[FAI]). We calculated the risk of perceived positive palpation pain for male participants as a function of hormone levels (DHEA-S, FAI) taking into account age and body mass index (BMI). RESULTS: Among more developed (Tanner stage 4-5) male adolescents, 22.7% (n = 62) reported palpation pain in the TM region. In these participants, FAI levels were approximately half that of individuals without such pain (p < .01). DHEA-S levels were about 30% lower in the pain group (p < .01). In multivariable regression analyses, the odds ratio (OR) for pain on palpation decreased to 0.75 (95% confidence interval [CI]: 0.57-0.98) per 10 units of FAI level compared to those without pain, after controlling for the effects of age and adjusted BMI. We observed the same effect for this subgroup per unit of DHEA-S serum level (OR = 0.71; 95% CI: 0.53-0.94). CONCLUSION: At subclinical lower levels of serum free TT and DHEA-S, male adolescents are more likely to report pain on standardised palpation of the masticatory muscles and/or TM joints. This finding supports the hypothesis that sex hormones may influence pain reporting.

Digital Workflow in Oral Splint Manufacturing.

AIM: The digital workflow used to manufacture an adjusted oral splint will be demonstrated in a patient case. MATERIALS AND METHODS: A 25-year-old female patient presented for management of her bruxism. Therefore, an adjusted oral splint was manufactured. A computer-aided motion analysis of the patient was conducted (JMA Optic, Amann Girrbach) and full-arch scans of the maxilla and mandible, a biocopy of the maxilla with bite fork as well as buccal scans of the centric jaw relation (Primescan, Dentsply Sirona). The jaw relation was determined beforehand by ballistic closing on a chairside fabricated anterior jig. The digital construction of a Michigan splint took place in the laboratory. The design was nested and milled from a polymethyl methacrylate (PMMA)-containing blank (CLEARsplint Disc, Astron Dental Corporation). RESULT: The oral splint was inserted into the patient's mouth and checked to ensure a tensionfree fit. The static and dynamic contact relationship was checked. During the follow-up visit, the patient reported an improvement in tension in the masticatory muscles. CONCLUSION: The procedure described allows for an adjusted oral splint to be manufactured in a purely digital workflow.

Long-term survival of monolithic tooth-supported lithium disilicate crowns fabricated using a chairside approach: 15-year results.

OBJECTIVES: To investigate the clinical performance of chairside fabricated tooth-supported posterior single crowns from lithium disilicate ceramic. MATERIALS AND METHODS: Thirty-four crowns (IPS e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) were inserted between 2006 and 2007 and again evaluated after 15 years. Survival and success rates were calculated according to Kaplan-Meier, and the quality of the crowns was evaluated by using modified United States Public Health (USPHS) criteria. RESULTS: Twenty-two crowns were available for recall; six patients were defined as dropouts. The mean observation period was 15.2 years (± 0.2). Six failures occurred (1 technical/5 biological) resulting in a survival rate of 80.1%. The success rate was 64.2%. The roughness of the crowns increased (p = 0.021) and the majority of adhesive gaps were discolored (p = 0.001) in comparison to baseline. The color, tooth, and crown integrity remained stable over the follow-up period (p ≥ 0.317). CONCLUSION: The fabrication of tooth-supported lithium disilicate crowns using a chairside approach yielded acceptable long-term survival and success rates. Due to discoloration, the long-term use of dual-cure self-adhesive resin cements might result in unpleasing esthetic results. CLINICAL RELEVANCE: The performance of posterior lithium disilicate single crowns revealed excellent to good clinical quality and an acceptable number of events after 15 years of clinical service.

Prevalence of temporomandibular disorders and bruxism in seniors.

BACKGROUND: Information on the prevalence of temporomandibular disorders (TMD) or possible/probable bruxism in seniors is heterogeneous and sparse. OBJECTIVES: To elucidate the prevalence of TMD and possible/probable bruxism in German adults aged 60 years and older. METHODS: Participants of the Interdisciplinary Longitudinal Study of Adult Development and Aging (ILSE) born between 1950-1952 (C1) and 1930-1932 (C2) were examined in 2014-2016 (fourth wave). The participants were surveyed and clinically examined by one calibrated examiner. Two questions of the Patient Health Questionnaire (PHQ) were utilised to evaluate self-reported bruxism. The clinical examination included signs of probable bruxism and the RDC/TMD examination protocol. RESULTS: Data from 191 participants were available. No RDC/TMD diagnosis was made in 83.2%. Of the participants, 15.2% received a single diagnosis and 1.6% multiple diagnoses that included disc displacements (9.4%) and degenerative joint diseases (8.9%). A total of 24.7% reported bruxism that included self-reported awake bruxism in 11.9% and sleep bruxism in 16.2%. Wear was clinically identified in 27.2% of the participants. No sex-related differences were observed. Significant differences were detected for probable bruxism between C1 (14.1%) and C2 (54.3%). CONCLUSION: In the German population aged 60 years and older, the prevalence of TMD is 16.8%. TMD is characterised by temporomandibular joint disorders, including disc displacements and degenerative joint disorders. Bruxism was observed in a quarter of the old population.

HOW TO IDENTIFY SUBGROUPS IN LONGITUDINAL CLINICAL DATA: TREATMENT RESPONSE PATTERNS IN PATIENTS WITH A SHORTENED DENTAL ARCH.

BACKGROUND: When dental patients seek care, treatments are not always successful,that is patients' oral health problems are not always eliminated or substantially reduced. Identifying these patients (treatment non-responders) is essential for clinical decision-making. Group-based trajectory modeling (GBTM) is rarely used in dentistry, but a promising statistical technique to identify non-responders in particular and clinical distinct patient groups in general in longitudinal data sets. AIM: Using group-based trajectory modeling, this study aimed to demonstrate how to identify oral health-related quality of life (OHRQoL) treatment response patterns by the example of patients with a shortened dental arch (SDA). METHODS: This paper is a secondary data analysis of a randomized controlled clinical trial. In this trial SDA patients received partial removable dental prostheses replacing missing teeth up to the first molars (N = 79) either or the dental arch ended with the second premolar that was present or replaced by a cantilever fixed dental prosthesis (N = 71). Up to ten follow-up examinations (1-2, 6, 12, 24, 36, 48, 60, 96, 120, and 180 months post-treatment) continued for 15 years. The outcome OHRQoL was assessed with the 49-item Oral Health Impact Profile (OHIP). Exploratory GBTM was performed to identify treatment response patterns. RESULTS: Two response patterns could be identified - "responders" and "non-responders." Responders' OHRQoL improved substantially and stayed primarily stable over the 15 years. Non-responders' OHRQoL did not improve considerably over time or worsened. While the SDA treatments were not related to the 2 response patterns, higher levels of functional, pain-related, psychological impairment in particular, and severely impaired OHRQoL in general predicted a non-responding OHRQoL pattern after treatment. Supplementary, a 3 pattern approach has been evaluated. CONCLUSIONS: Clustering patients according to certain longitudinal characteristics after treatment is generally important, but specifically identifying treatment in non-responders is central. With the increasing availability of OHRQoL data in clinical research and regular patient care, GBTM has become a powerful tool to investigate which dental treatment works for which patients.

Intraoral Repair of Chipping Due to Cohesive Failure-Results of a Nationwide Survey Among Dentists in Germany.

PURPOSE: To survey the materials favored by dentists for intraoral repair of cohesive chipping. MATERIALS AND METHODS: From August 2019 to February 2020, dentists were surveyed to determine the frequency of cohesive chipping experienced within the last 3 months and to identify their preferred approaches for intraoral repair. RESULTS: Of the participants, 42.5% observed chipping (n = 506). Participants favored the application of roughening devices, silane, and composite resins. Self-etching glass-ceramic primers or hydrofluoric acid were used for ceramic etching. CONCLUSION: Dentists apply a variety of materials for intraoral repair of chipping, including materials that are not approved for intraoral use. Int J Prosthodont 2023;36:216-218. doi: 10.11607/ijp.7098.

A Healthier Smile in the Past? Dental Caries and Diet in Early Neolithic Farming Communities from Central Germany.

Dental health is closely linked to an individual's health and diet. This bioarcheological study presents dental caries and stable isotope data obtained from prehistoric individuals (n = 101) from three Early Neolithic sites (c. 5500-4800 BCE) in central Germany. Dental caries and ante-mortem tooth loss (AMTL) were recorded and related to life history traits such as biological sex and age at death. Further, we correlate evidence on caries to carbon and nitrogen isotope data obtained from 83 individuals to assess the relationship between diet and caries. In 68.3% of the adults, carious lesions were present, with 10.3% of teeth affected. If AMTL is considered, the values increase by about 3%. The prevalence of subadults (18.4%) was significantly lower, with 1.8% carious teeth. The number of carious teeth correlated significantly with age but not sex. The isotopic data indicated an omnivorous terrestrial diet composed of domestic plants and animal derived protein but did not correlate with the prevalence of carious lesions. The combined evidence from caries and isotope analysis suggests a prevalence of starchy foods such as cereals in the diet of these early farmers, which aligns well with observations from other Early Neolithic sites but contrasts to Late Neolithic and Early Bronze Age populations in Germany.

Pull-off Force of Four Different Implant Cements Between Zirconia Crowns and Titanium Implant Abutments in Two Different Abutment Heights.

This study evaluated the pull-off force between titanium abutments and zirconia crowns that were bonded using four different cements and two abutment heights (AHs). In total, 24 titanium abutments (3-mm AH: n = 12; 5-mm AH: n = 12; taper: 7.5 degrees) and 24 zirconia crowns were designed, manufactured, cemented with one of four dental cements (one temporary, two semi-permanent, one permanent), stored in water for 24 hours, and thermocycled (37,500 cycles, equal to ~4 years in vivo). The pull-off force needed to separate the abutment and crown in each combination was determined eight times per combination of cement type and abutment height. Statistical analysis was conducted at a significance level of P < .05. The permanent self-adhesive composite cement showed a high pull-off force with a risk for crown fracture (mean: 381 N for 3-mm AH; 617 N for 5-mm AH). In contrast, the temporary zinc-oxide cement showed frequent premature decementation after thermocycling (mean: 14 N with 3-mm AH; 28 N with 5-mm AH). Both semi-permanent methacrylate-based cements ranked between the other cements (mean: 31 N/37 N for 3-mm AH; 120 N/72 N for 5-mm AH). Statistically significant differences were found between all cements (ANOVA P < .001). The abutment heights differed significantly for all cements (P < .005) except for the temporary zinc-oxide cement. Methacrylate-based cements were the most reliable cements for semi-permanent mounting of zirconia crowns on titanium abutments. They provide sufficient retention to avoid unintended loosening and are weak enough to remove the crown without causing damage.

Impact of an Oral Hygiene Intervention in People with and without Dementia on Oral Health Parameters-Results from the Oral Health, Bite Force, and Dementia (OrBiD) Pilot Study.

This study aimed to assess the influence of an oral hygiene intervention on oral health, depending on the degree of dementia. A clinical evaluation of oral health parameters (index of decayed, missing, and filled teeth (DMFT-index), periodontal screening index (PSI), oral hygiene index (OHI), and bleeding on probing (BOP)) was performed in 120 subjects assigned to five groups, based on the mini mental state examination (MMSE) at baseline and after 12 months. Each MMSE group (no dementia (noDem, MMSE 28-30), mild cognitive impairment (mCI, MMSE 25-27), mild dementia (mDem, MMSE 18-24), moderate dementia (modDem, MMSE 10-17), and severe dementia (sDem, MMSE ≤ 9)) was split into control (no intervention) and experimental groups (intervention on oral hygiene: increased frequency, daily usage of high-fluoride toothpaste). In total, 99 out of 120 subjects were included in the analysis. The dropout rate was high in subjects with modDem and sDem due to death. In subjects with noDem, mCI, and mDem, no changes in the DMFT were found, but improvements in the OHI, BOP, and PSI were observed. Subjects with modDem or sDem demonstrated a deterioration in DMFT; however, in these patients, OHI improved in all control and experimental groups, BOP improved in the experimental group only, and PSI did not improve at all. The scope of improving oral health parameters by increasing the recall frequency and by continuously using high fluoride toothpaste is at its limits in people with severe dementia. Multidimensional approaches should be sought to improve the oral health of vulnerable older patients.

[Prevalence of temporomandibular disorders in seniors-Symptom-related analyses in younger and older seniors]. / Prävalenz kraniomandibulärer Dysfunktionen bei Senioren ­ symptombezogene Analysen bei jüngeren und älteren Senioren.

BACKGROUND: Temporomandibular disorders (TMD) are common in the general population even in old age. Information on the prevalence of TMD in older people is sparse. OBJECTIVE: To present prevalence values for symptoms and signs of TMD in old people according to the research diagnostic criteria for temporomandibular disorders (RDC/TMD). To compare prevalence values between the age groups of 60-74 years (younger seniors) and ≥ 75 years (older seniors). MATERIAL AND METHODS: Subjects of the interdisciplinary longitudinal study of adult development (ILSE), a representative sample of old people in Germany, were examined between 2014-2016. Subjects of the urban area of Leipzig were chosen to examine symptoms and signs of TMD. RESULTS: The most prevalent symptom was orofacial pain (13.0%) in the aged participants (n = 192). Temporomandibular joint (TMJ) sounds were the most prevalent sign with values up to 35.5%. Gender comparisons revealed higher prevalence values for the symptom headache/migraine as well as for the signs TMJ sounds (especially clicking sounds) and limited mouth opening in females. Regarding age groups, significant differences were only observed for self-reported headache/migraine. CONCLUSION: Orofacial pain was reported by 13.0% of the subjects and TMJ sounds were observed in every third participant. Similar prevalence values for TMD symptoms and signs in younger and older seniors were found.

IMPACT OF SHORTENED DENTAL ARCH ON ORAL HEALTH-RELATED QUALITY OF LIFE.

BACKGROUND: A shortened dental arch (SDA) is an established treatment concept for patients with missing molars. However, little is known regarding long-term course of oral health-related quality of life (OHRQoL) in patients with SDA and the benefits from replacement of missing molars. OBJECTIVE: Purpose of this multi-center randomized clinical trial was to assess OHRQoL over a period of 15 years in patients with molar replacement by a removable partial denture (RPD) compared to patients with a restored SDA without molar replacement. METHODS: Patients at least 35 years of age with all molars missing in 1 jaw and at least the canine and one premolar present on each side were included. Patients received either a precision attachment-retained, RPD for replacement of missing molars (n = 79), or the dental arch ended with the second premolar (SDA) that had to be present or replaced by a cantilever fixed dental prosthesis (n = 71). Follow-up examinations continued for 15 years. OHRQoL was assessed with the 49-item Oral Health Impact Profile (OHIP). OHIP summary and dimension scores were longitudinally modeled in the statistical analyses to assess course of OHRQoL over time applying an intention-to-treat approach. In addition, scores for the OHRQoL dimensions Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact were analyzed. RESULTS: After an initial improvement in OHRQoL indicated by a mean decrease of 20.0 OHIP points with an effect size of 0.61 in the entire study population, OHRQoL stayed relatively constant over the entire follow-up period. Assuming a constant time and treatment effects over the study period, OHRQoL did not differ statistically significant between the 2 treatments (0.4 OHIP points; 95%-CI: 7.1 - 6.2). OHRQoL after treatment did not change notably over 15 years and was statistically nonsignificant as well (P = .872). Similar findings were observed in all 4 OHRQoL dimensions. CONCLUSIONS: In patients, missing all molars in one jaw OHRQoL improved providing RPD or restoring SDA to a clinically relevant degree. Treatment-related improvement remained mostly stable over a period of at least 15 years. Therefore, patients can be informed that both treatment concepts are equivalent concerning long-term OHRQoL. Accordingly, patients' preferences regarding treatment options should be granted priority in treatment decision making with the SDA treatment option being the default.

Impact of cement type and abutment height on pull-off force of zirconia reinforced lithium silicate crowns on titanium implant stock abutments: an in vitro study.

BACKGROUND: Pull-off forces of cement-retained zirconia reinforced lithium silicate (ZLS) in implant-supported single crowns on stock titanium abutments with respect to abutment height and implant cement were evaluated and compared. METHODS: Pull-off force of ZLS crowns on stock titanium abutments was evaluated concerning dental cement and abutment height. A total sample size of 64 stock abutments with heights of 3 mm (n = 32) and 5 mm (n = 32) was used. The ZLS crowns were cemented with four different types of cement (one temporary, two semi-permanent, and one permanent). After cementation, water storage, and thermocycling each sample was subjected to a pull-off test using a universal testing machine. RESULTS: The temporary cement showed the least pull-off force regardless of abutment height (3/5 mm: means 6 N/23 N), followed by the semi-permanent methacrylate-infiltrated zinc oxide cement (28 N/55 N), the semi-permanent methacrylate-based cement (103 N/163 N), and the permanent resin composite cement (238 N/820 N). Results of all types of cement differed statistically significantly from each other (p ≤ .012). The type of implant cement has an impact on the pull-off force of ZLS crowns and titanium abutments. CONCLUSIONS: Permanent cements present higher retention than semi-permanent ones, and temporary cements present the lowest values. The abutment height had a subordinate impact.

Cross-Contamination Risk of Dental Tray Adhesives: An In Vitro Study.

BACKGROUND: The aim of this study was to investigate the risk of cross-contamination in dental tray adhesives with reusable brush systems. METHODS: Four dental tray adhesives with different disinfectant components were examined for risk as a potential transmission medium for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus oralis, and Candida albicans. Bacterial and fungal strains were mixed with artificial saliva. The contaminated saliva was intentionally added to tray adhesive liquid samples. At baseline and up to 60 min, 100 microliters of each sample were collected and cultivated aerobically on Columbia and Sabouraud agar for 24 or 48 h, respectively. RESULTS: At baseline, contamination with Staphylococcus aureus and Candida albicans could be identified in three out of four adhesives. In the subsequent samples, low counts of up to 20 colony-forming units per milliliter could be observed for Staphylococcus aureus. All other strains did not form colonies at baseline or subsequently. Adhesives with isopropanol or ethyl acetate as disinfectant additives were most effective in preventing contamination, while adhesives with hydrogen chloride or acetone as a disinfectant additive were the least effective. CONCLUSION: Within 15 min, the tested adhesives appeared to be sufficiently bactericidal and fungicidal against all microorganisms tested.

Older Seniors during the COVID-19 Pandemic-Social Support and Oral Health-Related Quality of Life.

The coronavirus disease (COVID-19) has greatly affected all parts of private life and led to social distancing and self-isolation. Limited social support for older or frail people might have led to decreased oral health and its related quality of life. The current study aimed to investigate the social support of older seniors and self-perceived oral health-related quality of life (OHRQoL) over the course of the COVID-19 pandemic. Questionnaires were sent to all patients of the Dental Clinic of the University of Leipzig (Germany) aged 75, 80, or 85 years (n = 1228) at the end of February 2021. Besides demographic characteristics and care level, an adapted German version of the ENRICHD Social Support Inventory (ESSI-D) and the German Oral Health Impact Profile-14 (OHIP-14) were included. The response rate was 35.7% (n = 439). Twelve replies were not included in the data analysis as participants had either no interest, were cognitively impaired, or did not match the required age group. Analysis of ESSI-D revealed low social support for 13.2% (n = 53/403) of the seniors. No statistically significant impact of assigned care level on low social support was identified. Seniors with an assigned care level (CLyes) presented higher OHIP-14 sum scores (CLno/CLyes 6.43/10.12; p < 0.001). This was also true for six of the seven OHIP-14 domains, except for functional limitation. Regarding seniors with an assigned care level, a weak positive correlation was identified for sum scores of the ESSI-D and the OHIP-14 (r = 0.29). Despite the COVID-19 pandemic, older seniors reported high self-perceived social support. As seniors with an assigned care level revealed more impaired OHRQoL and a correlation with lower social support, special attention should be given to this vulnerable and frail group in times of a pandemic. When restrictions may minimize access to dental treatment and might negatively influence the oral health of older seniors, health care programs should offer more individual options for dental/medical appointments.

Dental tray adhesives and their role as potential transmission medium for microorganisms.

OBJECTIVES: This study aimed to evaluate the possible ability of dental impression tray adhesives to serve as a transmission medium for bacteria and fungi when reusable adhesive applicators are utilized. MATERIALS AND METHODS: Ten flasks with tray adhesive were monitored over a period of 12 weeks during clinical use for contamination with bacteria or fungi. Adhesive fluid samples were cultivated on eight different culture media. All grown colonies were identified by using mass spectrometry (MALDI-TOF). Isolates without reliable identification were either identified by Rapid ID 32 API-STREP V3.0 or by sequencing the 16S rRNA genes. RESULTS: After 4 weeks, bacterial growth was detected on chocolate blood agar plates in five different samples. The bacterial species were identified as Staphylococcus warnerii, Staphylococcus epidermidis, Staphylococcus pasteuri, Ralstonia insidiosa, and Alloiococcus otitidis. After 8 weeks Streptococcus oralis grew on a blood agar plate. In all samples, no fungi were identified. CONCLUSIONS: The disinfectant component of the tested tray adhesive seems to be effective. However, some bacteria survived in the flask for a clinically relevant time, which might result in a potential transmission to a new host.

DENTAL PATIENT-REPORTED OUTCOMES -- THE PROMISE OF DENTAL IMPLANTS.

In general dental practice, the use of implants is focused mostly on prosthodontic issues. That is, the replacement of missing teeth or the support of dental prostheses. However, there are other dental fields using implants such as orthodontics or maxillofacial prosthodontics. A classic way to measure success in implant dentistry is to look how long implants and the corresponding superstructure survive and are in function. Nevertheless, this alone is a very crude parameter. Therefore, biological and technical complications are taken in account additionally. Nonetheless, these objective measures do not well replicate the perception of the patient. That why, subjective measures, reflecting the perception of the patient are recommended to complement objective parameters. If these dental patient-reported outcome measures (dPROMs) are wisely chosen, they offer a wide variety of options. Besides comparing therapeutic effects by using the instruments' summary score only, dPROMs such as the Oral Health Impact Profile (OHIP) provide the opportunity to additionally assess patients` perceptions in the 4 dimensions of oral health-related quality of life. These are functional limitations, pain, esthetic issues as well as psychosocial impairment. Even the 5-item short form of the OHIP captures these dimensions and provides an efficient way to assess patients' perception with low administrative burden. This in turn offers new insights into the patient perspective and therefore helps improving shared decision making.

Polyoxymethylene as Material for Removable Partial Dentures-A Literature Review and Illustrating Case Report.

Compared to thermoplastic manufacturing techniques, computer-aided design (CAD) and computer-aided manufacturing (CAM) technologies make it easier to process modern restorative and prosthetic materials with improved material properties. In dentistry, tooth-colored alternatives to metal-based frameworks for application in removable dental prostheses (RDP) emerged. With regard to this aspect, the current article provides an overview of the specific material properties of polyoxymethylene (POM). Furthermore, it reviews scientific literature indexed in PubMed and Web of Science that focuses on RDPs fabricated from POM within the last 10 years. Finally, a prosthetic rehabilitation of a patient with a RDP fabricated from POM is illustrated and observations during a follow-up over 10 months are described. Scientific data and clinical observations indicate that polyoxymethylene is a promising material that bridges gaps in dental therapeutic options. While survival time may be limited due to wear, POM might be a favorable option for application in semi-permanent restorations.

Material preferences for tooth-supported 3-unit fixed dental prostheses: A survey of German dentists.

STATEMENT OF PROBLEM: Different material options are available for fixed dental prostheses (FDPs), but valid data on the favored materials of German dentists for 3-unit FDPs are lacking. It is unclear whether preferences depend on the individual characteristics of the dentists or their dental practices. PURPOSE: The purpose of this survey was to identify the preferred material selection of German dentists for the fabrication of tooth-supported 3-unit FDPs depending on the location of the abutment teeth and the individual characteristics of the dentist or the dental practice. MATERIAL AND METHODS: A survey was developed that included questions on the demographic characteristics (sex, area of expertise, age group, time since graduation, number of inhabitants, and the postal code of the dental practice or dental school) of the participating dentist and their preferred materials for the fabrication of tooth-supported 3-unit FDPs. Three clinical scenarios (anterior maxillary FDP, posterior maxillary FDP, posterior mandibular FDP) were presented. The dentists were allowed to select from predefined options or to give a free answer. For comparisons of characteristic associations, the number of inhabitants was chosen to represent the characteristics of the dental practice, and sex and time since graduation were selected to represent the characteristics of the dentist. Group comparisons were conducted with Chi-square tests (α=.05). RESULTS: A response of 721 dentists from all parts of Germany was received, and data from 688 dentists were included in the analyses. Ceramic was the most preferred material for the fabrication of 3-unit FDPs independent of the location of the abutment teeth with veneered zirconia as the favored option. Metal-ceramic was ranked second. The time since graduation ≤15 years was associated with a preference of ceramic over metal-ceramic for the anterior restoration (P<.001). CONCLUSIONS: Most participating dentists selected appropriate restorative materials depending on the individual clinical setting presented in the survey. For the anterior 3-unit FDP, time since graduation was associated with the preference for a restorative material. Some dentists selected lithium-X-silicate ceramics for situations beyond their recommended indication range.