Long-term performance of ceramic in/-onlays vs. cast gold partial crowns - a retrospective clinical study.

OBJECTIVES: To assess the long-term clinical performance of ceramic in-/onlays (CIOs) and cast gold partial crowns (CGPCs) in posterior teeth in terms of success, survival, complications (biological, technical) and quality. MATERIAL AND METHODS: In a retrospective study, a total of 325 patients were recorded after up to 24.8 years (mean 13.9 ± 3.8 years) having (pre-)molars restored with CIO (Empress I, Ivoclar Vivadent, n = 161) and CGPC (Degunorm, DeguDent, n = 164) by supervised undergraduate students. A total of 296 restorations were assessed clinically and radiologically in healthy and endodontically treated teeth using modified United States Public Health Service (USPHS) criteria. Cumulative success and survival rates of the restorations were calculated using Kaplan-Meier estimates. Biological and technical complications were recorded. Status of oral health comprising caries risk and localized periodontitis were assessed. RESULTS: The cumulative success rates of CIOs were 92.1% and of CGPCs 84.2% after mean service times of 14.5 years. The annual failure rates of total service times were 0.5% in teeth restored with CIO (n = 155) and 0.7% in teeth restored with CGPC (n = 163). The cumulative survival rates of CIOs were 93.9% after a mean service time of 15.2 years and decreased to 91.7% after 23.5 years. The cumulative survival rates of CGPCs were 92.6% after a mean service time of 14.9 years and 91.8% after 23.5 years. Complications in CIOs (n = 149) were ceramic fracture (6.7%), secondary caries (4.7%), endodontic complication (2.7%) and tooth fracture (1.3%) compared to CGPCs (n = 147) with endodontic complication (8.8%), secondary caries (4.8%) and decementation (2.0%). Endodontically treated teeth restored with CIO or CGPC revealed significantly less often success compared with corresponding vital teeth (p = .02). CIOs and CGPCs revealed clinically and radiographically good and excellent qualities with 71.8% (107/149) and 68% (100/147) without any significant differences regarding type of restoration. CONCLUSIONS: Both CIOs and CGPCs achieved high survival rates up to 24.8 years when performed by supervised undergraduate students. The longevity of the restorations may benefit from the intraoral repair of accessible defects and, in case of pulp infection or necrosis, an adequate endodontic management. CLINICAL RELEVANCE: CIOs and CGPCs made by supervised undergraduate students are proper restoration types in posterior teeth in the long-term. An adequate preparation design, meticulous care in the inserting technique and constant biofilm removal due to proper oral hygiene combined with professional maintenance care are substantial. The clinical long-term performance was mostly limited by ceramic fractures in CIOs and endodontic complications in CGPCs.

Antimicrobial effect of probiotic bacteriocins on Streptococcus mutans biofilm in a dynamic oral flow chamber model - an in vitro study.

Aim: To determine the antimicrobial activity of the bacteriocin-producing probiotic strains Streptococcus salivarius K12 and Streptococcus salivarius M18 alone or in combination against caries-associated Streptococcus mutans. Methods: Antimicrobial activity of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 growth and biofilm formation on hydroxyapatite (HA) discs was determined in a flow chamber model by recording the colony forming units (CFU/ml) after 48 h of co-cultivation. The biofilm was analyzed by scanning electron microscopy (SEM) and by confocal laser scanning microscopy (CLSM). Additionally, the simultaneous antagonism assay was used to assess the inhibitory effect of S. salivarius K12 and/or S. salivarius M18 against S. mutans ATCC 25175 and 21 clinical isolates of S. mutans. Results: Co-cultivation of S. mutans and S. salivarius K12 and/or S. salivarius M18 led to the inhibition of S. mutans viability, thereby, preventing its biofilm formation on HA discs. Furthermore, S. salivarius K12 and S. salivarius M18 exhibited antimicrobial activity against most clinical isolates of S. mutans. Conclusion: The in vitro flow chamber system used in this study allows the simulation of time-dependent administration of S. salivarius probiotic strains, either alone or in combination, to investigate the prevention of S. mutans biofilm formation in a standardized model.

Head and dental injuries among farriers and hoof care practitioners: A nationwide survey in Switzerland.

BACKGROUND/AIM: There is a paucity of evidence on injuries sustained by farriers and hoof care practitioners, two professions exposed to unique occupational hazards. The aim of this study was to collect and examine data on occupational head/face and dental injuries among farriers and hoof care practitioners in a nationwide survey in Switzerland. MATERIALS AND METHODS: Data on occupational head/face and dental injuries were gathered in a questionnaire-based, voluntary survey, which was mailed to all farriers and hoof care practitioners in Switzerland. The statistical analysis comprised multiple regressions with a nested design (α = 0.05). RESULTS: The survey included 278 respondents (response rate of 78.1%). Head/face injuries were more frequently reported by farriers than hoof care practitioners (60.6% and 20.7%, respectively). Among full-time workers, farriers had a higher chance of an occupational head/face injury compared with hoof care practitioners (p = .007). The rate of dental injuries, mainly related to a horse kick, was 11.1% and 1.9% among farriers and hoof care practitioners, respectively. Negligence in wearing mandatory eye protection was reported by 37.5% of respondents. CONCLUSIONS: Farriery and hoof care management entail a significant risk of occupational head/face and dental injuries. Preventive safety measures-eye protection in particular-and knowledge in dental first aid should be promoted among farriers and hoof care practitioners to decrease the frequency and severity of work-related injuries.

The Effect of Ligature Type on Lateral Tooth Movement during Orthodontic Treatment with Lingual Appliances-An In Vitro Study.

(1) Background: One of the most challenging parts in lingual orthodontics is the control and correction of the tip of anterior teeth, due to the occlusal open vertical slot of the incisors in lingual systems. The presented experimental in-vitro study was performed to determine the maximal tipping moment of the anterior teeth between two types of lingual brackets, the Incognito™ Appliance System (Incognito, TOP-Service, Bad Essen, Germany) and Tip-Bar™ system (Incognito, TOP-Service, Bad Essen, Germany). Furthermore, twelve different ligation methods and two different ligature materials were investigated. (2) Methods: The measurement was performed by assessing the stiffness and ultimate strength of the ligature in a uniaxial material testing machine (Instron, Norwood, MA, USA) using a 0.025 × 0.018 inch stainless steel wire. (3) The results showed that the highest precision for control tipping of anterior teeth was determined for the 0.010 inch Stainless Steel Tie (Pelz and Partner). Furthermore, the Tip-Bar™ brackets increased the maximal moment by 33.8% for elastic and steel ligatures. (4) Conclusions: The lateral tooth movement is highly dependent on the type of ligature and applied material during orthodontic treatment with lingual appliances. The use of 0.010 inch steel ligatures and the Tip-Bar™ bracket design results in better alignment in the anterior teeth segment.

Survey on the prevalence of occupational injuries to the head and teeth in automotive repair and maintenance in Switzerland.

Automotive mechanics are exposed to an increased risk for occupational injuries (OI) to the hands, arms, head and teeth. The aim of this study was to assess the self-reported prevalence of OIs to the head, including traumatic dental injuries (TDIs), among automotive repair and maintenance workers dealing with motorcycles, cars and vehicles over 3.5 tons. We surveyed healthy mechanics in Swiss automotive repair workshops from 2019 to 2021. Overall, 121 automotive repair and maintenance workers responded to our 12-item questionnaire concerning their professional experience, protective measures and occupational injuries to the head and teeth (response rate: 12%). 119 were considered eligible for inclusion and two were excluded. Most persons surveyed (94%) were males with more than 10 years of professional experience. Eighty-five (72%) reported occupational injuries in general, 37 (43.5%) specified OIs to the head or tooth area, and 16 stipulated that these cases teeth were affected. The most common self-reported diagnosis was tooth fracture (p=0.191). Traumatic dental injury in childhood increased the odds ratio (OR) for occupational injury to the head or teeth by a factor of 2.4 (95% CI: 1.1, 5.5, p=0.036). Age, gender and dental trauma in childhood may also influence the prevalence of occupational injuries in general in this cohort. We conclude that occupational dental accidents in automotive repair workshops can be reduced by raising awareness of this issue and by taking effective preventive measures.

Orthodontic Forced Eruption of Permanent Anterior Teeth with Subgingival Fractures: A Systematic Review.

(1) Background: To assess orthodontic forced eruption (OFE) as a pre-restorative procedure for non-restorable permanent teeth with subgingival dental hard tissue defects after dental trauma. (2) Methods: A systematic electronic search of three databases, namely, MEDLINE, Cochrane Library, and EMBASE, revealed a total of 2757 eligible publications. Randomized controlled clinical trials (RCT), retro- and prospective clinical studies, or case series (with a minimum of three patients) were reviewed. (3) Results: Thirteen full-text papers were included: one RCT, one prospective clinical trial, two retrospective cohort studies, and nine case series. Within case series, statistical significance between age and cause of fracture (p < 0.03) was determined. The mean extrusion rate of OFE was 1.5 mm a week within a four to six weeks treatment period followed by retention. Three OFE protocols for maxillary single teeth are available: 1. OFE without migration of gingiva and alveolar bone, 2. OFE with gingival migration and slight alveolar bone migration, and 3. OFE with migration of both gingiva and alveolar bone. (4) Conclusions: The current state of the evidence suggests that OFE is a feasible pre-treatment option for non-restorable permanent teeth. OFE can promote the migration of tooth surrounding hard and soft tissues in the esthetic zone. Root resorption does not seem to be a relevant side effect of OFE.

Clinical characterization of 266 patients and family members with cleft lip and/or palate with associated malformations and syndromes.

OBJECTIVES: To clinically characterize patients and family members with cleft lip and/or palate (CL/P) and associated congenital malformations or syndromes and propose possible inheritance patterns. MATERIALS AND METHODS: An observational study of patients with CL/P, including medical and family history and intra- and extra-oral examination of their family members, was performed. RESULTS: Two hundred sixty-six patients, 1257 family members, and 42 pedigrees were included in the study. The distribution of patients according to the cleft type was 57.9% with CLP, 25.2% with cleft palate (CPO), and 12.8% with cleft lip with/without alveolus (CL/A). Seventy-four (27.8%) patients had associated malformations, and 24 (9.2%) a syndrome. The skeletal (27.7%), cardiovascular (19.3%) systems, and eyes (22.9%) were most commonly affected. Pierre Robin Sequence (7 patients) and van der Woude (4) were the most common syndromes. The majority of patients with CPO (19/24) had an associate syndrome. The families had an average of 2.45 affected members. CONCLUSION: Individual and interfamilial phenotypic variability in patients with CL/P makes the understanding of etiopathogenesis challenging. CLINICAL RELEVANCE: The overall prevalence of individuals with CL/P and their pedigrees with associated malformations and syndromes emphasize the need for early identification, interdisciplinary, and long-term planning.

Compressive force strengthened the pro-inflammatory effect of zoledronic acid on il-1ß stimulated human periodontal fibroblasts.

OBJECTIVES: The number of patients in dentistry taking bisphosphonates (BP) increases every year. There are only little data about the influence of biomechanical stress due to orthodontic treatment and periodontal inflammation in BP patients. This study focused on the effects of the induced inflammation by IL-1ß in compressed human periodontal ligament fibroblasts (HPdLF) exposed to the nitrogen-containing BP zoledronate in vitro. MATERIALS AND METHODS: HPdLF were incubated with 5 µmol/l zoledronate and 10 ng/ml IL-1ß for 48 h. In the last 3 h, cells were exposed to a compressive, centrifugal force of 34.9 g/cm2. Cell viability was analyzed directly after the compressive force by MTT assay. Gene expression of COX-2 and IL-6 was investigated using quantitative qRT-PCR. PGE-2 and IL-6 protein secretion were measured via ELISA. RESULTS: The cell viability of HPdLF was not affected. Without inflammatory pre-stimulation, COX-2 expression was increased by compression and zoledronate. IL-6 expression was increased under compression. On secretion level, the combination of compression and zoledronate induced a slightly increase of IL-6 secretion. In contrast, inflammatory pre-stimulation strengthened the compressive upregulation of COX-2, as well as induced a higher PGE-2 secretion. Further addition of zoledronate to pre-stimulated cells additionally strengthened the compression-induced upregulation of COX-2 and IL-6 expression as well as protein secretion compared to all other groups. CONCLUSIONS: Biomechanical stress might trigger a pro-inflammatory potential of BP further enhanced in the presence of an inflammatory pre-stimulation. CLINICAL RELEVANCE: To prevent excessive host inflammatory responses, occlusal overloading and mechanical stress due to orthodontic treatment should be avoided in BP patients with untreated periodontitis.

Qualitative and quantitative changes in the oral bacterial flora occur shortly after implementation of fixed orthodontic appliances.

INTRODUCTION: In this pilot study, we aimed to determine qualitative and quantitative microbiological changes after the implementation of orthodontic appliances. METHODS: A total of 10 healthy patients aged 12-15 years were recruited who needed to undergo orthodontic treatment with buccal fixed appliances. Gingival conditions were assessed by the Gingival Index, Periodontal Screening Index, and Sulcus Bleeding Index. Microbiological samples were collected before and 1 week after the start of therapy at premolars and molars of the right upper quadrant. Bacterial species were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. RESULTS: The total number of bacteria increased. Six bacterial species were identified that are involved in the development of caries and other infectious processes. The bacteria selectively adapted more efficiently to the new oral milieu compared with the general oral microbial background. There was a significant increase in Streptococcus spp at the premolars and molars. In all individuals, symptoms of inflammation and gingivitis were detected as a response to the bacterial challenge. CONCLUSIONS: Orthodontic treatment induces significant changes in the oral microbial flora associated with gingivitis and an enhanced risk for cariogenic reactions within the first days of orthodontic treatment. To prevent or reduce infectious side effects, oral hygiene instructions and control of patients are necessary before and during the beginning of the therapy.

Interest in orthodontic tooth alignment in adult patients affected by periodontitis: A questionnaire-based cross-sectional pilot study.

BACKGROUND: Orthodontic treatment can successfully align pathologically migrated teeth and lead to improvement of periodontal stability in patients with periodontitis. Periodontic-orthodontic approaches have gained increasing attention in the past years. Here, we investigated the interest of adults affected by chronic periodontitis in undergoing orthodontic treatment as well as patient-related and tooth-related influence factors. METHODS: Periodontal and orthodontic measurements/indices were taken from 115 adult patients with moderate-to-severe periodontitis. The study participants answered a questionnaire investigating patient demographics, quality of life aspects, and their interest in undergoing orthodontic treatment. Correlations between clinical data, questionnaire responses, and this interest were analyzed by means of an age- and sex-adjusted multiple regression model. RESULTS: Two-thirds of the participants were interested in orthodontic therapy and indicated long-term healthy and esthetically appealing teeth as their main motives. A significant correlation was found between subjectively felt impaired dental esthetics and an interest in orthodontic treatment. However, there were no correlations with the severity of periodontitis, tooth alignment, or patient demographics, including sex. Older patients were significantly more often interested in orthodontic treatment. Most participants had never been provided with information about orthodontic treatment options for adults. CONCLUSIONS: A considerable number of adult patients with periodontitis were interested in orthodontics to improve tooth alignment. However, severity of periodontitis and tooth misalignment or demographic factors may not be indicative thereof. Therefore, dental practitioners need to be aware of patients wishing to align their teeth and to provide them with the relevant information and, if appropriate, enable interdisciplinary treatment planning.