Association between untreated caries and cariogenic bacteria in adolescents in Taiwan.

Background/purpose: There is a paucity of research focused on salivary bacteria analyzed through real-time polymerase chain reaction (qPCR) among adolescents. The current study determined the quantity of Streptococcus mutans (SM) and Lactobacillus (LB) in saliva obtained from Taiwanese adolescents and investigated the association between the oral bacteria and untreated dental caries. Materials and methods: This cross-sectional study recruited Taiwanese students aged 10-18. Saliva was collected using a Salivette kit and then analyzed through qPCR. The relative quantification values of SM and LB were coded based on mean fold ratios, with values > 2 coded as high and other values coded as low. Untreated dental caries was assessed through standard oral examinations. Univariate and multivariate logistic regression models were used to estimate the association between the levels of bacteria in the saliva of the study participants and the presence of untreated caries. Results: The study involved 421 adolescents. 56 (13.3%) had both SM and LB values of >2 and were coded as having high levels of bacteria, whereas the other 365 (86.7%) students were coded as having low levels. The multivariate logistic regression analysis revealed that adolescents who had high combined salivary SM and LB levels had an odds ratio of having untreated dental caries of 2.05 (95% CI = 1.09, 3.86, P = 0.027) compared with those who had low salivary SM and LB levels. Conclusion: The results of the present study indicate that salivary SM and LB levels are significantly associated with adolescents having untreated caries.

Fracture Characteristics of Commercial PEEK Dental Crowns: Combining the Effects of Aging Time and TiO2 Content.

Polyetheretherketone (PEEK) is an emerging thermoplastic polymer with good mechanical properties and an elastic modulus similar to that of alveolar bone. PEEK dental prostheses for computer-aided design/computer-aided manufacturing (CAD/CAM) systems on the market often have additives of titanium dioxide (TiO2) to strengthen their mechanical properties. However, the effects of combining aging, simulating a long-term intraoral environment, and TiO2 content on the fracture characteristics of PEEK dental prostheses have rarely been investigated. In this study, two types of commercially available PEEK blocks, containing 20% and 30% TiO2, were used to fabricate dental crowns by CAD/CAM systems and were aged for 5 and 10 h based on the ISO 13356 specifications. The compressive fracture load values of PEEK dental crowns were measured using a universal test machine. The morphology and crystallinity of the fracture surface were analyzed by scanning electron microscopy and an X-ray diffractometer, respectively. Statistical analysis was performed using the paired t-test (α = 0.05). Results showed no significant difference in the fracture load value of the test PEEK crowns with 20% and 30% TiO2 after 5 or 10 h of aging treatment; all test PEEK crowns have satisfactory fracture properties for clinical applications. Fracture surface analysis revealed that all test crowns fractured from the lingual side of the occlusal surface, with the fracture extending along the lingual sulcus to the lingual edge, showing a feather shape at the middle part of the fracture extension path and a coral shape at the end of the fracture. Crystalline analysis showed that PEEK crowns, regardless of aging time and TiO2 content, remained predominantly PEEK matrix and rutile phase TiO2. We would conclude that adding 20% or 30% TiO2 to PEEK crowns may have been sufficient to improve the fracture properties of PEEK crowns after 5 or 10 h of aging. Aging times below 10 h may still be safe for reducing the fracture properties of TiO2-containing PEEK crowns.

Influence of Aging on the Fracture Characteristics of Polyetheretherketone Dental Crowns: A Preliminary Study.

Although polyetheretherketone (PEEK) is becoming more widely used in dentistry applications, little is known about how aging will affect this material. Therefore, this study aimed to investigate the influence of an aging treatment on fracture characteristics of PEEK dental crowns. Additionally, the impact of the addition of titanium dioxide (TiO2) into PEEK was examined. Two types of commercial PEEK discs were used in this study, including TiO2-free and 20% TiO2-containing PEEK. The PEEK dental crowns were fabricated and aging-treated at 134 °C and 0.2 MPa for 5 h in accordance with the ISO 13356 specification before being cemented on artificial tooth abutments. The fracture loads of all crown samples were measured under compression tests. Results demonstrated that adding TiO2 enhanced the fracture load of PEEK crowns compared to TiO2-free PEEK crowns before the aging treatment. However, the aging treatment decreased the fracture load of TiO2-containing PEEK crowns while increasing the fracture load of TiO2-free PEEK crowns. The fracture morphology of TiO2-containing PEEK crowns revealed finer feather shapes than that of the TiO2-free PEEK crowns. We concluded that adding TiO2 increased the fracture load of PEEK crowns without aging treatment. Still, the aging treatment influenced the fracture load and microscopic fracture morphology of PEEK crowns, depending on the addition of TiO2.

Use of rubber dams during root canal treatment in Taiwan.

BACKGROUND/PURPOSE: Isolation of teeth with rubber dams is an important procedure for infection control in dentistry, especially in endodontic treatment. This study surveyed the prevalence of rubber dam usage in nonsurgical root canal treatment (RCT) by dentists under the National Health Insurance system in Taiwan. METHODS: A total of 1,332 completed RCT cases were randomly selected from a large database from the Bureau of National Health Insurance in Taiwan in 2004. The radiographs and dental charts of the selected cases were evaluated for the prevalence of rubber dam usage in RCT. The frequencies of rubber dam usage for RCT by dentists were compared between hospitals and private dental clinics and among six different regions in Taiwan. RESULTS: The overall prevalence of rubber dam usage for RCT by dentists under the National Health Insurance system in Taiwan was 16.5%. The frequency of rubber dam usage for RCT by dentists in hospitals (32.8%) was significantly higher than that (10.3%) in private dental clinics (p < 0.0001). However, there was no significant difference in the frequency of rubber dam usage for RCT by dentists among six different geographic regions in Taiwan. CONCLUSION: The prevalence of rubber dam usage for RCT by dentists in Taiwan is relatively low. Because rubber dam isolation of an endodontically-treated tooth can provide better infection control, increase patient protection, and improve treatment efficiency, there is an urgent need to advise dentists in Taiwan to use rubber dams for every RCT case.

Clinical study of patients with persistent orofacial pain.

OBJECTIVE: [corrected] To evaluate a sample of patients with persistent facial pain unresponsive to prior treatments. METHODS: Hospital records of 26 patients with persistent facial pain were reviewed (20 female and 6 male). RESULTS: Patients were classified into three groups according to their presenting symptoms: a)Group I, eight patients (30.7%) with severe, diffuse pain at the face, teeth or head; b)Group II, eight patients (30.7%) with chronic non-myofascial pain and; c)Group III, ten patients with chronic myofascial pain (38.4%). We find 11 different diagnoses among the 26 patients: pulpitis(7), leukemia(1), oropharyngeal tumor(1), atypical odontalgia(1), Eagle's syndrome(1), trigeminal neuralgia(4), continuous neuralgia(1), temporomandibular disorders (9), fibromyalgia (2), tension-type headache(1), conversion hysteria(2). After the treatment program all patients had a six-month follow-up period with pain relief, except the patient with tumor. CONCLUSION: The wide variability of orofacial pain diagnosis (benign to life-threatening diseases) indicates the necessity to reevaluate patients presenting recurrent pain that is refractory to the usual treatments.

Clinical study of patients with persistent orofacial pain

OBJETIVO: Avaliar uma amostra de doentes com dor facial persistente. MÉTODO: Foram revisados 26 prontuários de doentes com dor facial persistente (20 mulheres e 6 homens). RESULTADOS: Classificação dos doentes, após o diagnóstico: a)Grupo I, oito pacientes (30,7%) com dor facial difusa de fortíssima intensidade; b)Grupo II, oito pacientes (30,7%) com dor crônica de natureza não-miofascial e; c)Grupo III, dez pacientes com dor crônica miofascial (38,4%). Foram encontrados 11 diagnósticos diferentes entre os 26 pacientes: pulpites(7), leucemia(1), tumor de orofaringe(1), odontalgia atípica(1), síndrome de Eagle(1), neuralgia idiopática do trigêmeo(4), neuralgia atípica(1), disordens temporomandibular (9), fibromialgia(2) cefaléia tipo-tensão(1), histeria de conversão(2). O acompanhamento dos doentes, após receberem a respectiva terapia, foi de seis meses, com alívio da dor, exceto para o doente com tumor de orofaringe. CONCLUSAO: A variabilidade das fontes da dor facial inclui doenças benignas e doenças graves, sendo indispensável a reavaliaçâo de doentes que não respondem aos tratamentos convencionais para a dor.

Implantes osseointegrados na reabilitação de desdentado total com dor orofacial por disfunção temporomandibular: importância do tratamento sintomático. Caso clínico / Osseointegrated implants and rehabilitation of patients with temporomandibular disorders: the need of a symptomatic treatment. A clinical report

É discutido o caso de uma paciente com dor craniofacial por disfunção temporomandibular e cefaléia crônica. Ela recebera um tratamento oclusal reabilitador através de implantes osteointegrados. Embora os implantes para osteointegração sejam fatores importantes para estabilidade oclusal, principalmente em pacientes disfuncionados, eles devem ser utilizados na reabilitação final, após diagnóstico e tratamento sintomático da dor, quando esta é comprovadamente devido à disfunção. A presença de outras fontes de dor no segmento cefálico e o seu diagnóstico diferencial devem ser compreendidos, evitando-se a indicação incorreta dessa excelente terapia reabilitadora oral.