Investigation of the precision of a novel jaw tracking system in recording mandibular movements: A preliminary clinical study.

OBJECTIVES: This preliminary study aimed to clinically assess the precision of a novel optical jaw tracking system (JTS) in registering mandibular movements (MMs) of protrusion and mediotrusion. METHODS: Twenty healthy participants underwent recordings using Cyclops JTS (Itaka Way Med) for functional MMs of protrusion and laterotrusion by two trained clinicians. Each subject performed five registrations at different times according to a standardized pattern within one-month period. The angulations of protrusive and mediotrusive functional paths within the first 2 mm from the maximal intercuspal position (MIP) were calculated for each trace, using a data software for angle measurements. Descriptive statistics were used to assess the repeatability of the recordings for each participant and MM. Additionally, inferential statistics were carried out on standard deviation values obtained (α=0.05). RESULTS: The overall precision for all the patients was 7.07±3.37° for the protrusion angle, 5.24±2.24° for right laterotrusion and 5.14±3.06° for left laterotrusion angles. The protrusion angle ranged from 3.08° to 13.57°, while the right and left laterotrusion ranged from 1.82° to 9.42° and from 1.58° to 10.59°, respectively. No statistically significant differences were observed between different functional MM types and gender (p > 0.05). CONCLUSIONS: Recordings functional MMs of mediotrusion and protrusion using Cyclops JTS showed consistent repeatability, regardless of gender and functional MM type. The results revealed non-negligible variations that may be due to the patients' abilities to precisely reproduce jaw movements or to the operator's ability to consistently connect the kinesiograph. CLINICAL SIGNIFICANCE: Capturing functional MMs digitally and importing the data into dental CAD software is essential for virtual waxing in prosthetic rehabilitations to design a functionalized adapted occlusion. Establishing the repeatability of MM recordings by a JTS is a crucial step in better understanding this novel JTS in the market. This process could facilitate the interpretation of cusp angles, aid in CAD dynamic technical modeling, and enhance clinical data communication between clinicians and technicians in a modern workflow.

Influence of Thickness and Thermocycling on Tensile Strength of Two Resin-Based Cements Used for Overdenture Bar-Type Attachments: An In Vitro Study.

PURPOSE: This study aimed to evaluate the tensile strength of five different thicknesses of two resin cements placed between two titanium surfaces, before and after ageing. MATERIALS AND METHODS: One hundred titanium 5 grade models composed of two surfaces simulating a semiprecision attachment for overdenture and its housing in the framework, were used. Samples were cemented using two different resin cements (SoloCem and OT-Cem). Five groups representing five different cement thicknesses (from 50 to 250µm) were created by varying the housing diameter. A half of the sample underwent to a tensile strength test 24h after luting, while the other half after 30000 thermic cycles from 5°C to 55°C. Shapiro-Wilk and ANOVA with post-hoc tests were performed to relate the tensile strength to the variables: cement type, thermal ageing and cement thickness (p <0.05). RESULTS: Statistical differences were found between the cements both at T0 and T1; the mean values of tensile strength of SoloCem were three times higher than those of OT-Cem. The thermic cycles determined a reduction of the tensile force values for both cements; statistical evidence was found only for the SoloCem except for the 100µm thickness group. Significant differences were also found between the cement thicknesses of both cements, with 50µm and 100µm expressed the best tensile strength. Most of the fractures were of cohesive nature. CONCLUSION: SoloCem showed a higher tensile strength than OT-Cem but has been more stressed by the ageing. For each group the cement thickness influenced the tensile strength values with an inverse relationship.

Rehabilitation with implant-supported overdentures in preteens patients with ectodermal dysplasia: A cohort study.

INTRODUCTION: Hypohidrotic ectodermal dysplasia (HED) patients suffering of oligo-anodontia require early dental treatment to improve oral functions and reduce social impairment. The aim of this study was to evaluate the skeletal growth, implant and prosthetic survival rate, success, and complications after the rehabilitation with a maxillary denture and an implant-supported overdenture provided by a sliding bar in case of severe hypodontia/anodontia related to HED. MATERIALS AND METHODS: This retrospective cohort study began in 2009. Nine patients over 7 years old with HED and associated oligo-anodontia who presented at the University of Bologna for dental treatment were included in the study. They were first treated with conventional dentures and then with a maxillary denture and an implant-supported overdenture with a sliding bar connected to two implants placed in the anterior mandible. The subjects treated were followed for 3-12 years. In each case, orthopanoramic and lateral cephalometric radiographic exam were taken before implant placement and annually after prosthetic load. Vertical and transverse dimensions of the mandible in the symphysis area at implant sites were taken on the lateral cephalometric radiography at the time of implant placement and after 5 years from the prosthetic loading to assess the presence or absence of an anterior mandibular growth. Biologic and mechanical complications were also recorded at every visit. RESULTS: A mandibular vertical growth under the implant apex, at the implant neck, and a sagittal growth of the symphysis after 5 years from the prosthetic loading were observed and measured. Implant and prosthetic success and survival rates were 100% after 8.1 years (mean) follow-up period. No complications were reported except in one patient, where the repositioning of a retentive cap on the counter bar in the superstructure was necessary after 3 years from the prosthetic loading. CONCLUSIONS: The present study suggests that the growth of the mandible near implant sites continues even after their positioning. Implants can be successfully placed and provide support for prosthetic rehabilitation in preteens patients with HED.

Preliminary clinical study of the accuracy of a digital axiographic recording system for the assessment of sagittal condylar inclination.

OBJECTIVES: The aim of this study was to clinically evaluate the accuracy of a digital axiographic recording system in tracing the sagittal condylar inclination. METHODS: An axiographic examination that records the sagittal condylar path during protrusive/retrusive movement was performed on ten patients. Each subject was registered five different times by two different systems: 1) the Cadiax Gamma Diagnostic 4 computerized system as the control; 2) the Zebris Jaw Motion Analyser+  Optic System as the tested digital axiographic recording system. The records obtained allow to calculate the kinematic terminal transverse horizontal axis and the sagittal condylar inclination (SCI) at 3 and 5 mm along the pro-retrusive path. A linear mixed model was used to analyze if there was a statistically significant difference between the two systems. RESULTS: The mean left SCI value recorded by Zebris system were 49.81 ± 10.64° at 3 mm, 48.10 ± 11.04° at 5 mm, while the values recorded by Gamma system were 55.16° at 3 mm, 52.18° at 5 mm. The mean right SCI value recorded by Zebris system were 54.53 ± 10.26° at 3 mm, 51.85 ± 8.55° at 5 mm, while the values recorded by Gamma system were 49.68° at 3 mm, 48.23° at 5 mm. Linear mixed model showed no significant statistical difference between the two systems. CONCLUSIONS: Based on preliminary results, the Zebris Jaw Motion Analyzer+ Optic System demonstrates comparable accuracy to the Cadiax Gamma Diagnostic 4 when measuring sagittal condylar inclination. CLINICAL SIGNIFICANCE: The digital axiographic recording system enables to evaluate sagittal condylar inclination and to adjust virtual articulators in a digital workflow.

Comparison of the accuracy between full-arch digital scans and scannable impression materials: an in vitro study.

BACKGROUND: In some clinical cases, full-arch impression could be difficult to take correctly with the digital way. Patients with high flow salivary rate or with difficulties in mouth opening can still benefit from a conventional impression with elastomer materials that can be directly or indirectly digitized. The aim of this study was to compare the accuracy and precision of two different intraoral scanners (IOSs) and an impression material with scannable properties, by means of three-dimensional analysis of a complete dental arch. METHODS: An anatomical model of complete upper arch, modified with a Scan body placed in the retroincisive area, was used. It was firstly scanned by a desktop scanner to create a digital reference model. Then, 3 groups were created, each constituted by 5 samples. In the first group, 5 impressions were taken from the same master model with the scannable PVS material (Hydrorise Implant), 5 scans were taken using Trios4 (3Shape) and other 5 scans with iTero Element 5D (iTero). STL files obtained from IOSs, and scanned impressions were three-dimensionally superimposed on the STL file of the reference model using the Scan body geometry. RESULTS: The ANOVA Test (P<0.005) did not show any statistically significant difference between the accuracy and precision values of the groups. Each group shows clinically acceptable deviations from the reference model. CONCLUSIONS: Scannable polyvinylsiloxane impression materials are equally accurate and precise as the two IOSs tested in full-arch dentate impressions.

Evaluation of Tension and Deformation in a Mandibular Toronto Bridge Anchored on Three Fixtures Using Different Framework Materials, Abutment Systems, and Loading Conditions: A FEM Analysis.

OBJECTIVE: The aim of this study was to investigate by finite element method analysis the behaviour of a three-implant mandible Toronto framework made by three different materials, with two abutment systems and two loading conditions. MATERIALS AND METHODS: Three implants were virtually inserted in a mandible model in positions 3.6, 4.1, and 4.6. Three prosthetic framework bars with the same design and dimension (4.8 × 5.5 mm) were projected. The variables introduced in the computer model were the framework materials (glass fiber reinforced resin, Co-Cr, TiAl6V4), the abutment systems (Multi-Unit-Abutment [MUA]/OT-Bridge), and the loading conditions (500 N vertical load on all the framework area and 400 N on a 7-mm distal cantilever). The computer was programmed with physical properties of the materials as derived from the literature. Maximum tension and deformation values for each variable were registered at framework, screws, and abutment level and then compared. RESULTS: Metal frameworks Cr-Co and TiAl6V4 resulted in lower deformation than glass fiber-reinforced resin frameworks while presenting higher tension values. The OT-Bridge exhibited lower maximum tension and deformation values than the MUA system. The first loading condition reached higher tension and deformation values than the second and it resulted in more uniformly distributed load on all the framework area, especially with the OT-Bridge system. CONCLUSION: More rigid materials and OT-Bridge system decrease the deformation on the prosthetic components. Tension stresses are more uniformly distributed with glass fiber-reinforced resin, in the OT-Bridge system and avoiding cantilever loading.

Evaluation of Load Distribution in a Mandibular Model with Four Implants Depending on the Number of Prosthetic Screws Used for OT-Bridge System: A Finite Element Analysis (FEA).

In full-arch implant rehabilitations, when the anterior screw abutment channel compromises the aesthetic of the patient, the OT-Bridge system used with its Seeger rings may provide the necessary retention of the prosthesis. However, no studies have evaluated the forces generated at the Seeger level during loading. This Finite Element Analysis aims to investigate the mechanical behavior of Seeger rings in a mandibular model with four implants and an OT-Bridge system, used without one or two anterior prosthetic screws. A 400 N unilateral load was virtually applied on a 7 mm distal cantilever. Two different variables were considered: the constraint conditions using two or three screws instead of four and the three different framework materials (fiberglass reinforced resin, cobalt-chrome, TiAl6V4). The FEA analysis exhibited tensile and compressive forces on the Seeger closest to the loading point. With the resin framework, a tension force on abutment 3.3 generates a displacement from 5 to 10 times greater than that respectively expressed in metal framework materials. In a full-arch rehabilitation with four implants, the case with three prosthetic screws seems to be a safer and more predictable configuration instead of two. Considering the stress value exhibited and the mechanical properties of the Seeger, the presence of only two prosthetic screws could lead to permanent deformation of the Seeger in the screwless abutment closest to the loading point.

Assessment of Preload Loss after Cyclic Loading in the OT Bridge System in an "All-on-Four" Rehabilitation Model in the Absence of One and Two Prosthesis Screws.

The aim of this study was to evaluate the stability of prosthetic screws after applying cyclic loadings in an "all-on-four" rehabilitation model with the OT Bridge system. The model was tested both with and without anterior screws. Four implant analogues following the "all-on-four" concept were inserted in an edentulous mandibular resin model. An OT Bridge system with a Cr-Co prosthetic framework was fabricated. Depending on the presence or absence of one or two anterior screws on the implant analogues, three groups were created, i.e., Gr.1: three tightening screws, Gr.2: two tightening screws, Control Group: four tightening screws. Each single group underwent subsequent 400,000 cyclic loads, simulating approximately a year of chewing by using a dynamometer machine. This cycle was repeated five times for each group, and preload loss values were evaluated on each prosthetic screw after each cycle. All the data obtained were analyzed by one-way ANOVA and Student's t-test. No statistically significant differences after intragroup analysis were found. A statistically significant difference within the Gr.1 between the screws in positions 33 and 36, equal to 15.2% (p-value = 0.0176), was found. The OT Bridge seems a useful system to maintain the retention of a prosthesis during mechanical stress conditions even in the absence of one screw in an "all-on-four" rehabilitation. This could represent a good solution to solve the esthetic problem of the screw buccal access hole for fixed solutions.

Cranio-Mandibular Disorders after Whiplash Injury: A Mono-Institutional Clinical Study on 31 Patients.

BACKGROUND: Whiplash is a consequence of traumatic injuries, mostly related to road accidents, with variable clinical manifestations, also known as Whiplash Associated Disorders, such as neck, head and temporo-cranio-mandibular pain. METHODS: The current study aims to evaluate the onset and evolution of temporomandibular joint pain in people with whiplash in a study group treated with the use of Zimmer Collars (adjustable rigid cervical collars for neck immobilization), as compared to a control group. This prospective study included 31 patients followed by the Dental Prosthesis Department of the University of Bari "Aldo Moro": 20 patients with whiplash (age range: 20-39 years) treated with Zimmer collars and 11 patients with whiplash (age range: 20-33 years) who were not. Immediately after the whiplash occurred, a visual analogue scale (VAS) was used to describe the intensity of pain and to complete the chart of the European Academy of Craniomandibular Disorders. Five out of twenty patients, already treated with a Zimmer collar, wore an occlusal splint as well because of persistent pain reported at the 28-day and 60-day follow-up and were supported by pharmacological therapy with analgesics (paracetamol) and muscle relaxants (thiocolchicoside). RESULTS: During the last follow-up (at six months), three out of five patients displayed a residual VAS score of 3, 4, and 5, respectively, while the remaining two displayed a VAS of 0. In the control group, four out of eleven patients needed to wear an occlusal splint but without muscle relaxants and analgesics pharmacological therapy; these four corresponded to the patients showing a residual painful symptomatology, with VAS reaching value of 2, and also were the oldest patients of the group. Data regarding VAS values and Zimmer collar use, both at the first visit and six months later, were statistically analyzed. CONCLUSION: Our prospective study highlights how whiplash-associated acute disorders are often self-limiting over a period of few months, thus reducing the possibility of symptom chronicity; the latter seems to be strictly related to lesion severity, pre-existence of a craniomandibular dysfunction and patient age, but appears to be independent from Zimmer collar use, as statistically confirmed.

Obturator Prosthesis Rehabilitation after Maxillectomy: Functional and Aesthetical Analysis in 25 Patients.

The number of patients undergoing a surgical resection of the maxilla for oncological reasons is constantly increasing, the most common complication of which remains the communication between oral and nasal cavities. On the basis of data arising from the literature regarding the treatment options of maxillary oncological post-surgical defects, obturator prosthesis remains the most used worldwide. We studied 25 patients (with at least 1-year follow up) rehabilitated by obturator prosthesis after maxillary resection leading to oro-nasal communication, providing data on the objective/subjective evaluation of such rehabilitation and mastication performance measured by a two-color chewing gum test. The type of defect was classified according to the classification system proposed by Aramany. Among the patients in our study, 72% rated a higher score for either stability and retention than for aesthetic appearance, as confirmed by the Kapur score rated by clinicians. The two-color chewing gum test shows similar results as only one patient had insufficient chewing function. Interestingly, we found no correlation between the masticatory function and residual denture, confirming that the maxillary obturator remains a predictable solution in such patients regardless of the anatomical alterations following surgery.

Complete-Arch Accuracy of Four Intraoral Scanners: An In Vitro Study.

The purpose of this study is to define the accuracy of four intraoral scanners (IOS) through the analysis of digital impressions of a complete dental arch model. Eight metal inserts were placed on the model as reference points and then it was scanned with a laboratory scanner in order to obtain the reference model. Subsequently, the reference model was scanned with four IOS (Carestream 3600, CEREC Omnicam, True Definition Scanner, Trios 3Shape). Linear measurements were traced on an STL file between the chosen reference points and divided into four categories: three-element mesiodistal, five-element mesiodistal, diagonal, and contralateral measurements. The digital reference values for the measurements were then compared with the values obtained from the scans to analyze the accuracy of the IOS using ANOVA. There were no statistically significant differences between the measurements of the digital scans obtained with the four IOS systems for any of the measurement groups tested.

Qualitative Evaluation of the Effects of Professional Oral Hygiene Instruments on Prosthetic Ceramic Surfaces.

During professional hygiene procedures, different instruments used may cause various damage to dental prostheses. Deplaquing and scaling with curettes and ultrasonic instruments may inadvertently increase the surface roughness of the material and the risk of future bacterial adhesion and/or also compromise the marginal seal of the prosthesis. Hence, the aim of this study was to assess the qualitative effects of two types of curettes and one piezoelectric instrument with a stainless-steel tip on three types of metal-free samples. After treating the samples with different instrumentations, they were analyzed using the scanning electron microscope and then underwent a qualitative microanalysis by using a spectroscopy machine. All the materials tested in this study have undergone significant changes of their superficial structure after instrumentation both with mechanical and manual instruments. Plastic curettes appeared to be less aggressive than the other instruments. Disilicate samples show a significantly lower degree of surface glazing erosion compared to the zirconia sample with all the instruments used.

Severity of irritable bowel syndrome in patients with temporomandibular disorders: A case-control study.

BACKGROUND: To assess the risk and severity of IBS in a population of TMD patients. MATERIAL AND METHODS: Subjects for the study group were recruited from patients attending the Dental Clinic. Health controls (HC) were recruited among patients' friends and clinic staff. All subjects filled in the RDC/TMD questionnaire and the ROME III questionnaire for the diagnosis of IBS. The IBS Severity Scoring System (IBS-SSS) was used to evaluate the severity of each case of IBS. Categorical variables were compared through the Chi square test. The risk of having abdominal pain was analysed using logistic regression. RESULTS: Twenty-two (46.8%) cases of IBS were diagnosed among TMD patients, whereas only 4 (11.4%) were in the HC group. This difference was statistically significant (χ2(1)=11.6; p<.01). The differences in the distribution of IBS-SSS were statistically significant (χ2(3)=12.49; p<.05). The regression model resulted statistically significant (χ2(5)=24.08; p<.001, R2=.37): abdominal pain was significantly related to nonspecific physical symptoms independent of the other variables. CONCLUSIONS: TMD patients had a greater risk of having IBS compared to HC. TMD patients presented also more severe form of IBS than HC. Key words:Temporomandibular disorders, irritable bowel syndrome, facial pain, case-control study.

In Vitro Fracture Strength of Teeth Restored with Lithium Disilicate Onlays with and without Fiber Post Build-Up.

To our knowledge there is no data about the mechanical performance of indirect restoration adhesively cemented on teeth without an adequate build-up to provide the correct geometrical configuration. The aim of this study was to compare the fracture strength of human teeth restored with lithium disilicate onlays, with and without fiber post build-up. METHODS: Twenty human mandibular molars were horizontally sectioned and divided into two groups (n = 10). No treatment was applied in group A. Teeth in group B were endodontically treated, built-up using fiber post and composite core and prepared with a circumferential chamfer providing a 1 mm circumferential ferrule. Lithium disilicate onlays were pressed and luted on teeth using dual-curing luting composite. Teeth were tested under static load. Failures were classified as restorable or not restorable. Failure loads were analyzed with one-way analysis of variance. Failure modes were compared using Pearson's Chi-square tests. RESULTS: The mean fracture loads were 1383.5 N for group A and 1286.3 N for group B. No difference was found (p = 0.6). Ninety per cent of fractures were classified as not restorable in both groups, with no difference (p = 0.8). CONCLUSIONS: For teeth restored with adhesive procedures and lithium disilicate onlays, the presence of build-up with fiber post to provide retention and resistance form does not influence the fracture strength.

Survival Rates of Lithium Disilicate Single Restorations: A Retrospective Study.

PURPOSE: To assess the clinical performance of lithium disilicate single restorations on natural teeth. MATERIALS AND METHODS: All patients who received lithium disilicate single restorations between 2009 and 2013 at the dental clinic of the University of Ferrara were recalled for clinical evaluation. A total of 43 partial and total restorations in 17 patients were evaluated from a minimum of 36 months follow-up to a maximum of 81 months follow-up, with a mean follow-up of 51 months. RESULTS: The cumulative survival rate was 97.7%, and the cumulative success rate was 94.2%. CONCLUSION: Lithium disilicate can be successfully used for single-tooth restorations.

Effect of flap design and duration of surgery on acute postoperative symptoms and signs after extraction of lower third molars: A randomized prospective study.

Background. Different surgical variables are assumed to play a role in postoperative course after lower third molar extraction. The aim of study was to assess whether flap design and duration of surgery can influence acute postoperative symptoms and signs after lower third molar extraction. Methods. Twenty-five patients scheduled for lower third molar extraction were included in this study and randomly assigned to two groups in terms of flap design: group A (envelope flap) and group B (triangular flap). Swelling and trismus were assessed before and after surgery on days 0, 2 and 7. Pain was assessed for seven days after surgery. Maximum postoperative pain was chosen as the main outcome variable. ANOVA was used to assess differences between the groups regarding maximum postoperative pain, trismus and swelling at 2- and 7-day intervals. Pearson's correlation coefficient was used to assess correlation between duration of surgery and postoperative symptoms and signs. Results. No significant difference was found between the two flap designs for any postoperative symptoms and signs. The duration of surgery was found to be correlated with both trismus (r = -0.44, P = 0.04) and swelling (r = 0.59, P = 0.004) as assessed 2 days after surgery. No associations were found between duration of surgery and maximum postoperative pain and trismus and swelling at 7-day interval. Conclusion. Within the limits of the present study, the duration of surgery, and not the flap design, affected the acute postoperative symptoms and signs after lower third molar extraction.

The use of monolithic lithium disilicate for posterior screw-retained implant crowns.

Lithium disilicate is typically used for fabricating prosthetic crowns to be cemented on teeth or implant abutments. However, its use for producing screw-retained implant crowns has been less commonly described. This report describes the use of monolithic lithium disilicate for a screw-retained implant crowns.

Simplified edentulous treatment: A multicenter randomized controlled trial to evaluate the timing and clinical outcomes of the technique.

STATEMENT OF PROBLEM: The time and cost of conventional complete denture procedures have been questioned in favor of simplified and faster methods. Whether the simplified edentulous treatment (SET) method yields complete dentures with acceptable outcomes is unclear. PURPOSE: The purpose of this randomized clinical trial (RCT) was to evaluate the outcomes of 2 techniques in providing complete dentures: the conventional and the SET methods. MATERIAL AND METHODS: Three Italian academic institutions participated in this single-blind parallel RCT. In total, 64 participants were selected and agreed to join the study. They were allocated randomly to 1 of 2 treatment groups, the conventional and SET group: 32 participants per group, 50% women in each group. Treatment was provided by final year predoctoral dental students. The time required for the clinical and laboratory procedures, the number of clinical sessions, and the laboratory returns were recorded. The clinical quality of the dentures and participant satisfaction were evaluated using questionnaires. Differences between treatment group outcomes were analyzed with 2-tailed independent sample Student t tests for clinical and technical timing and clinical and technical steps and Mann-Whitney U tests for denture quality and participant satisfaction (α=.05). RESULTS: The clinical time required (-34%, P<.001), number of clinical sessions (-34%, P<.001), and laboratory returns (-46.5%, P<.001) were significantly lower for the SET than for the conventional method. The laboratory time required (-10.6%) was not significantly less with the SET method (P=.06). Participant satisfaction (P=.816) and prosthodontist ratings of denture quality (P=.539) were comparable between the groups. The participants appreciated the reduced number of clinical sessions with SET (P=.003). CONCLUSIONS: Simplified edentulous treatment may be considered a reliable method for providing complete dentures in a shorter timeframe while maintaining denture quality and patient satisfaction.

High risk of temporomandibular disorder in irritable bowel syndrome: Is there a correlation with greater illness severity?

AIM: To investigate the prevalence and the risk of temporomandibular disorders (TMDs) in patients with irritable bowel syndrome (IBS) (including each subtype: constipation, diarrhoea, and mixed) compared to the general population. METHODS: Between January 2014 and December 2015 we enrolled consecutively adult patients diagnosed with IBS at the outpatient clinic of the University of Salerno and healthy controls (HC) without IBS. At enrollment, we analyzed all patients for the presence of TMDs according to the Research Diagnostic Criteria for TMD. RESULTS: We enrolled 91 IBS patients (23 IBS-D, 30 IBS-C and 38 IBS-M) and 57 HC in the study. We found a higher risk of having TMD (OR = 3.41, 95%CI: 1.66-7.01) compared to the HC. The risk of having TMD was independent of IBS-subtype. Multiple regression analysis showed that facial pain was positively related to abdominal pain and higher level of depression. CONCLUSION: IBS patients had a more than three times greater risk of TMD compared to HC. The risk of having TMD was similar in different IBS subtypes. IBS patients that also fulfilled criteria for TMD seem to share along with chronic facial and abdominal pain a significant co-occurrence with psychiatric disorders and female preponderance.

Qualitative evaluation of the adesive interface between lithium disilicate, luting composite and natural tooth.

Aim of this work was to qualitatively evaluate the interface between tooth, luting composite and lithium disilicate surface using a scanning electron microscope (SEM). An extracted restoration-free human molar was stored in physiological solution until it was embedded in an autopolimerysing acrylic resin. A standard preparation for overlay was completed and after preparation an anatomic overlay was waxed on the tooth and then hot pressed using lithium disilicate ceramic. After cementation the sample was dissected and the section was analysed using an Automatic Micromet (Remet s.a.s) and the section was analyzed using a scanning electron microscope (SEM). SEM evaluation of the tooth showed the three layers seamlessly; by increasing the enlargement the interface did not change.