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.

Preserving soft tissue after placing implants in fresh extraction sockets in the maxillary esthetic zone and a prosthetic template for interim crown fabrication: a prospective study.

STATEMENT OF PROBLEM: The technique of immediate implant placement is said to have success rates similar to those of implantation into a healed socket. An implant-supported restoration in an esthetic area must achieve a harmonious balance of functional, esthetic, and biologic imperatives to be considered effective. PURPOSE: The purpose of this clinical study was to assess the height of the interproximal gingival papillae adjacent to immediate implants with immediate loading. The hypothesis was that specific positioning of the proximal contact areas of the interim crowns would facilitate the maintenance or regeneration of the interproximal papilla. MATERIAL AND METHODS: Twenty-eight participants were provided implants (n=36) in the anterior maxillary area that were loaded with a specifically contoured interim crown immediately after tooth extraction. The proximal contact areas of the interim crowns were positioned 5 to 6 mm incisal to the interproximal bony crest by using a prosthetic template. Papilla height was classified according to a previously described papilla index. A comparison was made between the papilla height before the extraction, at interim crown placement after the implant placement, and at 6 and 12 months postoperatively. Parametric and nonparametric tests were used when appropriate (Kolmogorov-Smirnov). Significance was expressed at the α=.05 level. Cross tables were used to describe the changes in the papilla index score. RESULTS: During the 1-year follow-up, the score of the distal and mesial papilla indices increased significantly (repeated-measures Friedman exact test; P=.035 and P=.002). CONCLUSIONS: This prospective study indicated that the use of a prosthetic template for positioning an interim crown on immediately placed implants and for ensuring that the proximal contact areas of the crown with adjacent teeth are 5 to 6 mm incisal to the interproximal bony crest does not seem to hinder the maintenance or regeneration of the height of the interproximal papillae.

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.

Accuracy of a new photometric jaw tracking system in the frontal plane at different recording distances: An in-vitro study.

OBJECTIVES: To evaluate the accuracy of a new photometric jaw tracking system (JTS) in recording linear vertical movements in the frontal plane at different distances. METHODS: A mandibular plaster cast of a patient was placed on a simulation machine capable of linear movements along two spatial axes. Cyclops JTS (Itaka) was adapted to the plaster cast, while the head frame was attached to the simulation machine. The latter performed five linear movements from 20 to 40 mm in the y-axis; each movement was repeated five times at five different recording distance (380 to 420 mm). The recorded movements were measured and compared with those obtained with a laser Doppler vibrometer (LDV) for accuracy analysis. Data were statistically processed (α = 0.05). RESULTS: No statistically significant differences were found between Cyclops and LDV measurements on the y- and z-axes (p = 0.5). Changes in linear vertical motion and distance positions did not affect the accuracy, which remained relatively constant with similar trends and values less than 1 % for each parameter variation. The best condition observed was linear vertical movement of 30 mm at 420 mm (0.010 ± 0.023 mm). CONCLUSIONS: Cyclops has proven to be an accurate JTS in recording linear vertical movements in the frontal plane at different recording distances. For optimal recordings, the scanner should be placed as close as possible to the markers; excessive vertical movements decreased the accuracy. However, this study has limitations and requires in-vivo confirmations. CLINICAL SIGNIFICANCE: The tested JTS proved accurate in recording linear vertical movements in the frontal plane. However, given the limitations of the study, further investigation under real conditions is needed to support prosthetic and gnathological rehabilitations.

An in-vitro study on accuracy of modular templates used to fully guide implants in combination with bone reduction for complete arch restorations: experts versus students.

OBJECTIVES: This in-vitro study evaluates the accuracy of modular surgical templates used to fully guide implants in combination with bone reduction, performed by expert and students, for complete arch restorations. METHODS: All the procedures were performed by dental students of the final year and an expert clinician, on twelve edentulous mandible models. A virtual implant planning, simulating a complete arch restoration on six implants were performed. Three different surgical guides were designed and printed to allow conventional fully guided implant placement (group 1); fully guided implant placement with modular guides (group 2); and fully guided implant placement after bone reduction, with similar, modular guides (group 3). After implant placement, optical scans of the study models were taken. Surface deviation and accuracy were evaluated and compared between groups and subgroups. RESULTS: A total of 12 surgical templates were used. Of these, Two templates in each group were used by two different students, while, the other six templates were used by an expert clinician as follows: one template with screwed anchor pins and one with pushed anchor pins in each group. A total of 72 implants were placed. Statistically significant difference was found between different template designs, when the implants were placed by an expert clinician. No statistically significant difference was found between expert and students, except the deviation in an angle value (students 2.13±1.46° versus expert 0.90±0.91°; P Value=0.0447) in the group 3. A statistically significant difference was found in favor of screwed anchor pins, in the group 1, in horizontal deviation (screwed pins 0.18±0.13 mm versus pushed pins 0.56±0.28 mm; P Value=0.0124; Table 5). No statistically significant difference was found between different template designs when the fully guided implants were placed by students, in both angle and horizontally (P=0.2787 and P=0.6601, respectively). A statistically significant difference was found between groups when the implants were placed by an expert clinician, with better value using screwed anchor pins, in the horizontal plane (P= 0.0293) but not in angle (P= 0.3380). CONCLUSIONS: Modular templates provide a similar level of accuracy to conventional, one-piece guides. Screwed pins should be used to fix the base portion of the modular guides. Further clinical studies are needed to confirm these preliminary results. CLINICAL SIGNIFICANCE: Modular surgical guides provide comparable accuracy to conventional, single-piece guides, however they offer more possibilities, helping in bone reduction and immediate loading procedures. Screwed anchor pins used to fix the base portion of the modular guides provide better final results than pushed pins.

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.

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.

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.

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.

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.

The use of a prosthetic template to maintain the papilla in the esthetic zone for immediate implant placement by means of a radiographic procedure.

Implant placement in the esthetic zone requires precise preoperative diagnosis and treatment planning combined with excellent clinical skills. One of the most important factors needed to achieve an optimal esthetic outcome, in addition to the 3-dimensional (3-D) positioning of the dental implant, is to maintain or regenerate the interproximal papilla. This article describes a technique to fabricate a template that includes important aspects of rehabilitation in this area.

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.

Explaining pain after lower third molar extraction by preoperative pain assessment.

PURPOSE: To evaluate whether preoperative pain sensitivity testing and emotional perception of pain could explain the level of postoperative pain after lower third molar extraction. PATIENTS AND METHODS: Twenty-three patients (16 women, 7 men) scheduled for lower third molar extraction were enrolled in the study. Patients preoperatively were submitted to a nociceptive stimulus by a cold pressor test (immersion of the hand into ice water). Preoperative pain tolerance (seconds), algosity and unpleasantness (visual analog scale), and dental anxiety (Modified Dental Anxiety Scale) were assessed. The duration of surgery was recorded (minutes). Postoperative pain ratings were taken by self-reported registrations on a 100-mm visual analog scale during the 6 days after surgery. Separate stepwise regression analyses were performed to evaluate the usefulness of preoperative scores in explaining the overall maximum postoperative pain level and postoperative pain rates at different intervals. RESULTS: Preoperative unpleasantness related to the nociceptive stimulus was found to be the best predictor of maximum postoperative pain (adjusted R(2) = 0.39, P = .001). Demographic information (age) and preoperative (dental anxiety, pain tolerance, algosity) and intraoperative (duration of surgery) factors were not correlated with postoperative pain. CONCLUSIONS: These results show that a simple preoperative test is useful to identify patients at risk of developing greater pain after third molar surgery. They are characterized by a higher level of reported pain or unpleasantness after exposure to a nociceptive stimulus. This test may be tailored to specific patient needs for postoperative treatment.

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.

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.

Glenoid fossa osteoma resulting in a progressive malocclusion: a case report.

An osteoma is a benign tumor essentially restricted to the craniofacial skeleton. Osteomas occur most frequently in the frontal, ethmoid, and maxillary sinuses, and rarely affect the glenoid fossa. Osteomas are usually pain-free and remain silent, ie, symptom-free, for many years but may lead to occlusal changes. The report describes the case of an adult man with an osteoma who presented with a chief complaint of malocclusion and who was misdiagnosed. The case points to the diagnostic reasoning necessary to arrive at a correct diagnosis, especially when signs and symptoms, as well as pathology, are rare, eg, not familiar to the clinician.