Roughness of the Surface of Zirconia Reinforced Lithium Disilicate Ceramic Treated by Different Procedures

Lithium disilicate and zirconia are the two most popular materials for aesthetic and dental prosthetic work; however, due to their limitations, a new material is being researched, namely zirconia-reinforced lithium disilicate, the surface of which is treated with different procedures to achieve the best possible surface properties. In this study, the surface of zirconia-reinforced lithium disilicate glass-ceramic was treated using different methods (conventional and laser) to determine the effects of the treatment procedures on the surface properties and surface roughness to achieve a higher strength of adhesion from the self-adhesive resin cement to zirconia-reinforced lithium disilicate. The treated surfaces were investigated using profilometry, X-ray diffraction and energy dispersive X-ray fluorescence. The results obtained were statistically evaluated. The results show that the surface roughness is highest for the samples treated with Er:YAG (erbium-doped yttrium aluminium garnet laser) and silanisation. Furthermore, the surface treatment procedures applied did not change the composition of the surface.

Self-Massage and Low-Level Laser in Treatment of Masseter Myalgia: Short-Term Effect

INTRODUCTION

The aim of this study was to explore the efficiency of massage in the treatment of masseter myalgia compared with biostimulatory laser.

MATERIALS AND METHODS

The instrument Diagnostic Criteria for Temporomandibular Disorders was used to select subjects and monitor treatment outcome. 54 subjects with masseter myalgia of more than 3 months in duration were invited to participated and 42 cases were available at the end and analyzed. Age range was 16-67 years (median 33, interquartile range 25-53), 36% subjects was ≥40 years and there were 62% females in both groups. Both treatment groups (self-massage and laser) had 21 participants and were monitored one months after the start of treatment. Age, gender, distress, somatization, catastrophizing, hypervigilance, health competence and oral parafunctions were also assessed as factors that could influence effectiveness of treatment.

RESULTS

Laser and massage are effective in reducing symptoms of chronic myalgia of the masseter in self-reported limitation of jaw function and reducing pain intensities (p<0.001). Increase of mouth opening was present in both groups, but mainly significant in laser group. The differences in the amount of change between groups were not significant. Psychological characteristics and parafunctions, present before the treatment, age and gender did not have major affect the effectiveness of treatment.

CONCLUSION

Both treatment modalities are effective in treatment of chronic myalgia in short-term.

Audiological evaluation of patients with cleidocranial dysplasia (CCD)

OBJECTIVE

The description of clinical manifestation of hearing problems in cleidocranial dysplasia (CCD) remains limited and incomplete, since CCD constitutes a rare congenital disorder. The study aims to provide a complex panel analysis of the auditory system in patients suffering from the disease.

PATIENTS AND METHODS

The study group consisted of 4 children with CCD (aged: 12-15), who underwent orthodontic treatment. A full panel analysis of their auditory systems was performed, including high-frequency audiometry and a new method of middle ear assessment - WBT (Wideband Tympanometry).

RESULTS

A slight conductive hearing loss was diagnosed in 3 out of 4 patients. While high frequency audiometry has shown a deterioration of hearing in 3 patients, in one case, the obtained thresholds were within the normal range. A decrease of absorbance in low frequencies has been observed in one or both ears. Only one patient has had a shift of maximum absorbance towards high frequencies in the left ear.

CONCLUSIONS

The presented manuscript is the first with a complete evaluation of the auditory system comprising 4 cases of children in a similar age group. All of the examined patients presented an air-bone gap indicating conductive disorders.

Healthcare Utilization and Patients' Perspectives After Receiving a Positive Genetic Test for Familial Hypercholesterolemia

BACKGROUND

The MyCode Community Health Initiative (MyCode) is returning actionable results from whole exome sequencing. Familial hypercholesterolemia (FH) is an inherited condition characterized by premature cardiovascular disease.

METHODS

We used multiple methods to assess care in 28 MyCode participants who received FH results. Chart reviews were conducted on 23 individuals in the sample and 7 individuals participated semistructured interviews.

RESULTS

Chart reviews for 23 individuals with a Geisinger primary care provider found that 4 individuals (17% of 23) were at LDL-C (low-density lipoprotein cholesterol) goal (of either LDL-C <100 mg/dL for primary prevention and LDL-C <70 mg/dL for secondary prevention) and 17 individuals (74% of 23) were prescribed lipid-lowering therapy before genetic result disclosure. After disclosure of the genetic test result, 5 individuals (22% of 23) met their LDL-C goal and 18 individuals (78% of 23) were prescribed lipid-lowering therapy. Follow-up care about this result was not documented for 4 individuals (17% of 23). Changes to intensity of medication management were made for 8 individuals (47% of 17 individuals previously prescribed lipid-lowering therapy). Interviewed individuals (n=7) were not surprised by their result as all knew they had high cholesterol; however, individuals did not seem to discern FH as a separate condition from their high cholesterol.

CONCLUSIONS

Among individuals receiving genetic diagnosis of FH, >25% had no changes to lipid-lowering therapy, despite not being at LDL-C goal and learning their high cholesterol is related to a genetic condition requiring more aggressive treatment. Individuals and clinicians may have an inadequate understanding of FH as a distinct condition requiring enhanced medical management.

Highly Charged Rydberg Ions from the Coulomb Explosion of Clusters

Ion emission from a nanoplasma produced in the interaction of intense optical laser pulses with argon clusters is studied resolving simultaneously charge states and recoil energies. By applying appropriate static electric fields we observe that a significant fraction of the ions Ar^{q+} (q=1-7) has electrons with binding energies lower than 150 meV; i.e., n_{Ryd}≥15 levels are populated. Charge state changes observed on a μs time scale can be attributed to electron emission due to autoionizing Rydberg states, indicating that high-ℓ Rydberg levels are populated as well. The experiments support theoretical predictions that a significant fraction of delocalized electrons, which are bound with hundreds of eV to the nanoplasma after the laser exposure, fill up meV bound ion states in the adiabatic expansion. We expect the process to be relevant for the long-term evolution of expanding laser-induced dense plasmas in general.

High performance charge-state resolving ion energy analyzer optimized for intense laser studies on low-density cluster targets

We report on a versatile ion analyzer which is capable to resolve ion charge states and energies with a resolution of E/ΔE = 100 at 75 keV/nucleon. Charge states are identified by their characteristic deflection in a magnetic field, whereas the ion energies are independently determined by a time-of-flight measurement. To monitor the signals a delay-line detector is used which records ion impact positions and times in each laser shot. Compared to conventional Thomson parabola spectrometers our instrument provides a low background measurement, hence a superior dynamic range. Further features are an improved energy resolution and a significantly increased transmission. We demonstrate the performance by showing charge-state resolved ion energy spectra from the Coulomb explosion of a low-density target, i.e., silver clusters exposed to intense femtosecond laser pulses.

Prosthetic modalities used to treat cleft palate patients in a university clinic: a 10-year review

Cleft palate patients are not usually seen in general dental clinics, but this congenital anomaly is one of the most frequent of cases. General dental practitioners are usually unwilling or/and not sufficiently trained to treat such patients for whom rehabilitation and interdisciplinary cooperation is often needed. The aim of this study was to determine the incidence of prosthetic modalities most frequently used by licensed prosthodontists for prosthetic rehabilitation of cleft palate patients. Participants in this study were 56 cleft palate patients (aged 23-66 years) who received prosthetic treatment between 2000 and 2010. Patients' dental status and prosthetic modalities used were noted from patient records archived at Department of Prosthodontics, School of Dental Medicine, University of Zagreb. Data analyses revealed that combined prosthetic constructions (fixed + removable, p < 0.05) were the most frequently used. In a group of molar teeth, the most frequent fixed prosthetic modalities were crowns with rests; in a group of premolar teeth, telescopic crowns; on canines, metal ceramic crowns and telescopic crowns; and in a group of incisors, metal ceramic pontics (p < 0.05). Understanding the distribution of prosthetic modalities for cleft palate patients could serve to guide dental practitioners towards planning adequate prosthetic treatment for their patients since only a well-planned prosthetic therapy will result in satisfactory function and alleviation of the deformities.

Denture relining as an indicator of residual ridge resorption

AIM

Residual ridges change in shape and reduce in size due to alveolar bone resorption. Therefore, the purpose was to investigate changes in denture base thickness (DBT) and interocclusal rest space (IRS) with regard to the denture relining procedure.

METHODS

The IRS and DBT were measured (before and after denture relining) in the case of 74 patients and their removable dental prostheses by using a precise sliding gauge. The DBT measuring was performed in 6 points for maxillary and in 3 points for mandibular removable dental prosthesis. The IRS values were measured as the distance (in mm) between the incisal edges of the maxillary and mandibular central incisors with patient's mandible in a physiological "rest position" with head and neck in the upright posture.

RESULTS

In a group of patients wearing maxillary and mandibular removable dental prosthesis mean values of DBT after denture relining were statistically significantly higher (p <0.05) in almost all measuring points. The IRS mean values after relining were statistically significantly lower (p <0.05). Statistically significant differences (p <0.05) of DBT were also observed in groups of "day-night time" and "day time" denture wearers, and in a group of patients for whom a period shorter than one year had passed since the last tooth extraction and the time when a functional impression for removable dental prostheses was taken.

CONCLUSION

The DBT and IRS values change after the denture relining procedure due to the alveolar bone resorption. Therefore, these measures could be used as resorption indicators in dental practice.

Expression of contact allergy in undergoing prosthodontic therapy patients with oral diseases

AIM

Contact allergy is a postponed reaction of hypersensitivity where a localised cutaneous or mucosal lesion occurs due to a recurrent contact with an allergen. Placement of a fixed or removable prosthetic replacement into the oral cavity causes corrosive processes on the surface of the restoration and discharge of ions, which as haptens can induce allergic reactions. The purpose of this study was to examine occurrence of allergies to basic and auxiliary restorative dental materials in patients with lichen, stomatitis and stomatopyrosis by means of an epicutaneous allergy test.

METHODS

The study included 32 patients with a fixed and/or removable replacement and 7 patients with one of the mentioned diagnoses, but without any replacement. Testing was conducted using a standard method (patch test), and hypersensitivity to 13 most common allergens in prosthodontics was examined.

RESULTS

The research results revealed higher frequency of positive allergic reactions in persons with the mentioned diseases and with a restoration. Patients with lichen indicated positive patch test in the majority of cases. The allergens of nickel, cobalt and chromium demonstrated the highest score of positive results, and negative score was found for dibutylphthalate and HH mix. Stomatopyrosis was more common in persons with hypersensitivity to chromium. A lower incidence of positive allergic reactions to epoxide resins was found in female than in male subjects.

CONCLUSIONS

The epicutaneous (patch) test performed in the subjects examined in this study, showed that the majority of positive reactions was caused by mixes of nickel, cobalt and chromium; however, unwanted reactions also to other auxiliary materials used in dental practice should also be considered.

Screening of fixed prosthodontic dentures after five years of use in relation to material and construction

The aim of this study was to screen patients with fixed prosthodontic appliances that were in oral cavity for a period of 5 years or more and to assess clinically and radiologically root caries, gingival recession, pocket formation, alveolar ridge resorption, as well as gingival (GI) and plaque index (PI). The aim also was to find out the differences between materials and constructions, between abutment and non-abutment teeth, and to find out the need for replacement. A total of 260 patients and their orthopantomograms were examined, with a total of 2,265 teeth, 610 being bridge abutments and 246 being crowns. The most frequent were metal+ acrylic veneer crowns or bridges. Root caries was found under the abutments in 10-20%; however abutments with ceramic crowns had the lowest percentage of caries (p < 0.01). Alveolar ridge resorption, pocket formation deeper than 3 mm and gingival recession of various degree was found in 50% of the cases, again with the lowest percentage of ceramic-fused-to-metal appliances (p < 0.01). Pocket depth was registered in significantly higher percentage in metal-acrylic veneer appliances compared to natural teeth (p < 0.01), while there was no significant difference between metal-ceramic appliances and natural teeth (p > 0.05). Although the worst findings were recorded for metal- + acrylic veneer crowns for PI, no significant difference existed between crowns of different material or non-abutment teeth (p > 0.05). There was statistically significant difference between abutments with metal + acrylic veneer crowns, full metal crowns, metal ceramic crowns and non-abutments for GI scores. Higher percentage of scores 0 and 1 was recorded for metal ceramic crowns and non-abutments and significantly higher percentage of scores 2 and 3 was recorded for metal + acrylic veneer crowns and full metallic crowns. Almost 50% of metal-ceramic abutments had no pathologic findings. Almost 30% of the patients needed replacement, or even some abutments to be extracted and therefore a new prosthodontic appliance.

Oral status, aesthetic materials and frequency of crowns and bridges in patients with fixed prosthetic appliances living in the Metković region

The aim of the study was to examine oral status in patients of the Metković region with fixed prosthodontic appliances. The aim was also to evaluate aesthetic materials used, and difference between the frequency of crowns and bridges dependent on patient's age and frequency of visits to dentist. The examination was performed on 212 dental patients with fixed prosthetic appliances, from the Public Health Center "Metković". A questionnaire was created for the purpose of this study and was filled in by the patients. The dentist registered oral status. Descriptive statistics and chi 2 tests were used for the data analysis. Following conclusions were made: 1. The examined patients had relatively high caries (tooth decay), gangrene and residual roots prevalence, the oral hygiene was not appropriate, calculus and gingivitis were diagnosed in all patients (100%) and these facts point out to the insufficient preventive oral health care in the Metković region, as well as to the insufficient self-perception on the proper oral hygiene maintenance. 2. Patients who visit their dentist regularly (once a year or more) have significantly more crowns than bridges than the patients who visit their dentist irregularly or when in pain (p < 0.01). 3. Almost all fixed prosthetic appliances not older than 10 years were made of porcelain (98%), while acrylic veneer crowns (or chromasite) were more frequent in appliances older than 10 or 15 years (p < 0.01). There was no gender difference dependent on the material used (p > 0.05). High frequency of porcelain was attributed to the high economic status of this region, as well as to a dentist's preference.

Influence of age and gender on radiomorphometric indices of the mandible in removable denture wearers

The objective of this study was to measure and assess a number of radiomorphometric indices of the mandibular removable denture wearers taking into account age and gender. In a total of 136 dental panoramic radiographs (DPR) the following parameters were evaluated: MI = thickness of the mandibular cortex below the mental foramen, AI = thickness at the antegonion and GI = thickness at gonion; PMI = MI/distance between the low border of the mandible and the low border of the mental foramen, and MCI = mandibular cortical index, based on the assessment of the 3 categories of cortical appearance due to the resorptive changes. There were 40 male patients (mean age 72.7; range 56 to 84 years) and 96 female patients (mean age 69.7; range 48 to 86 years). Patients were grouped according to age into three age groups (1 = less than 65 years; 2 = 65-75 years; 3 = more than 75 years). The results revealed that MI, PMI, AI and GI showed a general downward trend with age for the both sexes until 75 years of age when the mean values of GI, AI and MI begun to fall down sharply for females compared to males. The difference was significant between age groups and gender for GI and AI. Only two categories (C2 and C3) of MCI have been recognized in our study sample, due to the relatively old age groups of patients with removable dentures. However, significantly higher incidence of C3 existed in the oldest group of females.

Analysis of occlusal contacts in different types of prosthodontic appliances, Eichner classifications, presence RCP-ICP slide and the type of occlusion

The aim of the study was to determine the number and the type of the occlusal contacts (strong, weak) with respect to the type of the prosthodontic appliance (fixed, removable, combined fixed-removable) and with respect to the Eichner classification in patients with their appliances being in a good function for a long time. The aim of the study was also to determine the number and the type of the occlusal contacts (strong, weak) with respect to the type of occlusion (canine guided, group function or balanced) and the presence of the RCP-ICP slide. A total of 440 patients with different types of prosthodontic appliances were examined for the antagonistic occlusal contacts using occlusal strips of 11 microm and 50 microm. The average number of occlusal contacts was 10.5 for the upper and 10.46 for the lower posterior teeth, approximately 5 on each side of the tooth arch. The results of the study suggest that the biggest number of occlusal contacts were recorded for the small span fixed appliances (2 on average), the greater span fixed and fixed-removable prosthodontic appliances exhibited 1.6 occlusal contacts, and the removable complete denture exhibited 1.2 contact per the tooth in the posterior region. The number of the hard occlusal contacts was significantly greater in fixed and fixed-removable prosthodontic appliances in comparison with the complete dentures (p < 0.05), while there was no significant difference between the prosthodontic appliances for the weak occlusal contacts (p > 0.05). The overall number of the occlusal contacts, as well as the number of the hard occlusal contacts was significantly greater in the Eichner class I cases (p < 0.05) in comparison with the Eichner classes II and III. The number of the weak occlusal contacts showed no significant differences with respect to the Eichner classification (p > 0.05). There was no significant difference in the number of occlusal contacts between the appliances with RCP-ICP slide and where ICP and RCP corresponded (p > 0.05).

Distribution of craniofacial variables in south Dalmatian and middle Croatian populations

The objective of the present work was to determine some relevant craniofacial parameters, particularly in relation to sex, for the study of the distribution of basic head and face types, and to investigate craniofacial and morphological differences between two population samples. The study sample comprised 100 subjects of both sex aged 18 to 30 from South Dalmatia and 200 subjects from Middle Croatia. Eight basic craniofacial variables were measured to obtain head, forehead and face indexes. The data indicate that average values of all variables can be used as standard craniofacial parameters for the examined population groups. All the craniofacial variables are considerably higher in men than in women (p < 0.05). In the South Dalmatian population mesocephalia (48.0%) and leptoprosopia (82.0%) prevail, while in the Middle Croatian population the brachycephalia (62.0%), and euriprosopia (73.5%) are present to a greater degree. The most significant craniofacial and morphological differences between the examined study samples are head width (Eu-Eu), face width (Zy-Zy), and forehead height (Tr-N). They were found to be statistically significant in the examined Middle Croatian population (p < 0.05). The presented measurements are highly relevant to orthodontic diagnostics and therapy.

Vomer as relevant factor in the mastication forces transmission system

In the region of the posterior segment of bony palate and nasal cavities in both sides, the following three bones come together: the upper jaw, the palatal and the sphenoid bones. The perpendicular upper palate lamina laterally leans on the corpus of the upper jaw and on the wing process of the sphenoid bone. It is the posterior bony transmission system that has been selected as a separate study entity, which is otherwise a functionally inseparable part of the overall system of trajectories of mastication forces. It is a supporting element that begins at the dental alveolus of the wisdom tooth, ascends along the tuber maxillae and by the wing process of the sphenoid bone transmits the mastication load to the body of the sphenoid bone, i.e. into the mid-portion of the neurocranial base. By observing the characteristics of the vomer and measurement of distances between its morphological markings, or craniometric landmarks, together with its fitting into the harmonic analysis of face and head, the essential role of vomer has been established in regard to the trajectory system of mastication forces which has enabled us to create the basis for further biomechanical research of this phenomenon using photoelasticimetric procedures.

The use of cadaver dogs in locating scattered, scavenged human remains: preliminary field test results

Specially trained air scent detection canines (Canis familiaris) are commonly used by law enforcement to detect narcotics, explosives or contraband, and by fire investigators to detect the presence of accelerants. Dogs are also used by police, military, and civilian groups to locate lost or missing persons, as well as victims of natural or mass disasters. A further subspecialty is "cadaver" searching, or the use of canines to locate buried or concealed human remains. Recent forensic investigations in central Alberta demonstrated that the use of cadaver dogs could be expanded to include locating partial, scattered human remains dispersed by repeated animal scavenging. Eight dog-and-handler teams participated in a two-month training program using human and animal remains in various stages of decay as scent sources. Ten blind field tests were then conducted which simulated actual search conditions. Recovery rates ranged between 57% and 100%, indicating that properly trained cadaver dogs can make significant contributions in the location and recovery of scattered human remains.

Some periodontological parameters in patients with oesophagogastric passage insufficiency

The aim of this study was to examine the state of oral hygiene (OHI), the presence of tooth calculus and the condition of the gingiva on the group of 101 patient with oesophagogastric passage insufficiency. The control was group of 78 examines without clinical signs of oesophagogastric disease. The plaque was visualised by plaque revelator and recorded on each tooth. The calculus and condition of gingiva was determined according to the modified instruction of WHO, 1987. Both parameters were determined for each sextant of upper and lower jaw. The results of the OHI on the patients with oesophagogastric passage insufficiency (0.3, SD 0.126) was statistically different (p < 0.01) in comparison with control group (0.51, SD 0.25). Pathological changes of gingiva were more prominent in patient with insufficiency and that difference was statistically significant (p < 0.05). Calculus was more evident in control group but statistically insignificant (p < 0.1). The data show that insufficiency of oesophagogastric passage can cause pathological changes of gingiva while the lower OHI and less prominent calculus could be explained probably by better oral hygiene of patients because of bad taste in mouths.

Postmortem insect activity may mimic perimortem sexual assault clothing patterns

Determination of perimortem sexual assault can be confounded in homicide cases in which only badly decomposed or skeletal remains are recovered. One indicator of assault is a characteristic pattern of clothing disarray, including tearing, removal, or displacement of clothing. Preliminary findings from two studies of clothed pig carrion of approximate human size (59 to 162 kg) reveal that postmortem insect activity, particularly maggot masses, and natural decompositional changes such as bloating can produce changes to clothing which mirror those seen in cases of sexual assault.