Showing papers in "Journal of Oral Rehabilitation in 2007"

Salivary secretion, taste and hyposalivation

Abstract: Summary Saliva has many essential functions. As the first digestive fluid in the alimentary canal, saliva is secreted in response to food, assisting intake and initiating the digestion of starch and lipids. During this process, saliva acts as a solvent of taste substances and affects taste sensitivity. Clinically, a more important role is in the maintenance of oral health, including the protection of teeth and mucosa from infections, maintenance of the milieu of taste receptors, and communication ability through speech. Variations in salivary flow can be affected, reversibly or irreversibly, by numerous physiological and pathological factors. Decreased salivary flow results in clinically significant oral discomfort that may manifest as increased caries, susceptibility to oral candidiasis, altered taste sensation or as a host of other problems. Hyposalivation is a condition that is frequently encountered in dental practice. The most common cause is the use of certain systemic medications, which put the elderly at greater risk because they are usually more medicated. Other causes include high doses of radiation and certain diseases such as Sjogren’s syndrome. This article reviews the mechanism of salivary secretion, effect of saliva on taste, importance of saliva in oral health, and hyposalivation in relation to ageing, medicine and/or disease and management of hyposalivation.

Denture-related stomatitis: identification of aetiological and predisposing factors - a large cohort.

Abstract: The aim of this study was to identify and characterize aetiological and predisposing factors in denture-related stomatitis (DRS), by means of a case-control, transversal study, in a large cohort of 140 persons wearing removable maxillary polymethylamethacrylate prostheses. Data were obtained by (1) a questionnaire that included the identification of the subject, demographic and social data, medical history and behaviour; (2) intra-oral examination; (3) evaluation of the prosthesis; (4) microbiological examination; (5) yeast identification and analyses using Epi-info and the chi-square test. Results showed significant associations between DRS and yeasts, gender, age and alcohol consumption. We also found a significant relationship between the presence of yeasts and hyposalivation and decreased salivary pH. We found a highly significant difference between groups with and without DRS concerning the presence or absence of yeasts, regardless of the sample origin. Most cases of DRS showed the presence of Candida albicans. The results confirm a highly significant difference between groups with and without DRS concerning the presence or absence of yeasts.

Bonding of resin composites to etchable ceramic surfaces - an insight review of the chemical aspects on surface conditioning.

Abstract: The longevity of silane promoted adhesion of the surface conditioned etchable ceramic materials is a continuous and costly concern in dentistry. Moreover, it poses a functional and aesthetic dilemma both for the dentist and the patient. Several methods for surface conditioning exist, however some of them are not any more widely in clinical use. Tribochemical silica-coating combined with silane application, compared in vitro and in vivo to some other silanization protocols, is according to the literature a clinically proved, relevant adhesion promotion method to enhance bonding of resin composites to etchable ceramics. The repair of fractured ceramic with tribochemical silica-coating and followed by a silane application is, according to the literature a relevant adhesion promotion method in prosthetic dentistry. Silica-coating is followed by a silane coupling agent application. The bonding is adequate for clinical use according to the literature study.

A two-colour chewing gum test for masticatory efficiency: development of different assessment methods.

Abstract: Objective: The aim of this study was to investigate different assessment methods of a two-colour chewing gum test for masticatory efficiency to determine its validity for research and clinical purposes. Materials and methods: Twenty adult volunteers, eleven women and nine men (mean age of 27.5 years), participated in this study. All participants perceived their masticatory efficiency as normal. The task was to chew five samples of a two-colour chewing gum for 5, 10, 20, 30 and 50 cycles respectively. Maximum bite force was measured. All samples were assessed twice by two independent operators both, as 'bolus' and after flattening to 1 mm thick 'wafers'. The latter were scanned and the unmixed pixels counted using Adobe Photoshop Elements((R)) to calculate the ratio of unmixed colour to the total surface. Results: Digital image processing confirmed a significant correlation between colour mixing and chewing duration (P < 0.001). Subjective assessment proved less accurate with fair to substantial intra-examiner agreement for 'bolus' (0.20 < kappa < 0.63) and substantial to almost perfect agreement for 'wafer' (0.60 < kappa < 0.88). Inter-examiner agreement was consistently moderate or substantial only for specimen chewed 20 cycles or longer. No significant correlation was found between the colour mixture and the maximum bite force. Conclusion: Digital image processing of the two-colour chewing gum test specimen provides reliable quantitative data for chewing efficiency. Visual assessments were less reliable but might still be useful in screening for chewing deficiencies in a clinical setting. In this context, the test should be performed with a flattened specimen chewed, probably for 20 cycles.

Clinical evaluation of the marginal fit of cast crowns--validation of the silicone replica method.

Abstract: Summary Replication of the space between a tooth and its cast crown, using a light-body silicone supported by a heavy-body silicone, is a recognized technique to evaluate the quality of a restoration. This study validates a similar method that is of great clinical and experimental interest. Whatever the type of silicone used, comparison is possible between different technical procedures of crown elaboration (type of impression, type of material, method of spacing, etc.). If an appropriate silicone is used, the cement space may be reproduced and its thickness measured, whatever the localization (cervical, axial, occlusal).

A global perspective on changes in the burden of caries and periodontitis: implications for dentistry*

Abstract: The structure and contents of most oral health care systems and the contents of dental curricula reflect a deep-rooted tradition for attempting to cure oral diseases by refined technological means. However, better oral health conditions for the world's populations necessitate the application of up-to-date scientific knowledge to control the major oral diseases. This review points out that not only should the structure and contents of oral health care delivery systems be based on state-of-the-art knowledge about the biology of the oral diseases; they must also take into account the trends for change in caries and periodontal diseases within and between populations, and acknowledge the impact of changes in treatment philosophies for these trends. The oral disease profiles for populations in low- and high-income countries are briefly described, and it is concluded that the rapidly changing disease profiles observed in high-income countries necessitate re-thinking of the future role and organization of dentistry in such countries. The priorities for low- and middle-income countries must be to avoid repeating the mistakes made in the high-income countries. Instead, these societies might take advantage of setting priorities based on a population-based common risk factor approach. If such an approach is adopted, the training of personnel with oral health care competence must be rethought. The authors suggest three different cadres of dental care providers to be considered for an approach that allows health care planners in different populations around the world to prioritize appropriate oral health care with due respect for the socio-economic conditions prevailing.

Effects of mechanical and chemical methods on denture biofilm accumulation

Abstract: The aim of this study was to quantify biofilm on the internal surface of upper complete dentures following six possible cleansing methods. Thirty-six edentulous subjects were submitted to a time-series trial and dentures were cleansed according to six methods: (i) rinsing with water; (ii) soaking in an alkaline peroxide solution (Bonyplus); (iii) brushing with dentifrice (Dentu-Creme) and soft Johnson and Johnson's toothbrush; (iv) combination between soaking and brushing according to methods 2 and 3; (v) brushing with dentifrice (Dentu-Creme) and soft Oral B toothbrush; (vi) combination between soaking and brushing according to methods 2 and 5. Each method was randomly used throughout 21 days. Denture biofilm was disclosed by 1% neutral red solution and quantified by means of digital photos taken from the internal surface. The six methods presented significant differences in percentage of biofilm coverage (repeated measures anova, P < 0.0001). Method 1 showed the highest values, 2 was intermediate and other results were the lowest. The most efficacious approach was 6. Biofilm tended to accumulate predominantly over specific zones of the denture base, but this pattern did not change regardless of the method employed. It can be concluded that brushing alone was more effective than the chemical method employed. The best results were obtained by a combination of methods.

Bone density assessments of oral implant sites using computerized tomography.

Abstract: The type and architecture of bone are considered to affect its load-bearing capacity and it has been indicated that poorer quality bone is associated with higher implant failure rates. To date, bone classifications have only provided subjective methods for pre-operative assessment, which can be considered unreliable. The aim of this study was to evaluate variations of the bone density in designated endosseous implant sites using computerized tomography. One hundred and thirty-one designated implant sites in 72 patients were utilized. Computerized tomography results indicated that bone densities may vary markedly when different areas of a designated implant site are compared. It has been observed that a difference in the bone density exists for the four regions within the oral area, with the anterior mandible yielding mean density values of 944.9+/-207 Hounsfield units (HU)>anterior maxilla, 715.8+/-190 HU>posterior mandible, 674.3+/-227 HU>posterior maxilla and 455.1+/-122 HU. Computerized tomography may be a useful tool for determining the bone density of interest areas before implant placement, and this valuable information about the bone quality provides dental practitioners to make better treatment planning regarding the implant positions.

Japanese version of the Oral Health Impact Profile (OHIP-J).

Abstract: The objective of the study was to develop a Japanese version of the Oral Health Impact Profile (OHIP). The original 49 items were translated using a forward-backward method following accepted cultural adaptation guidelines. A de novo development of Japanese items was conducted to establish content validity. The associations between the OHIP summary score and self-reported oral health (n = 220) and self-reported denture quality (n = 155) were investigated for construct validity. The association between the OHIP summary score and six oral conditions (n = 227) were also tested. The responsiveness of the instrument was established by comparing the score before and after using newly fabricated removable partial dentures (n = 30). The test-retest reliability (n = 37) and internal consistency (n = 251) were also calculated. After the de novo development, five new items were added to the OHIP. The priori hypothesized associations between the OHIP score and oral health conditions were confirmed (P < 0.001). The change in the OHIP scores from 63.6 to 40.6 (P < 0.001) supports the responsiveness of the instrument. Intra-class correlation coefficients of 0.81 and Cronbach's alpha of 0.98 indicate high test-retest reliability and internal consistency of the instrument's summary score. Sufficient discriminative and evaluative psychometric properties of the currently developed Japanese version of the OHIP in typical target populations make the instrument suitable for assessing the oral health-related quality of life in cross-sectional as well as longitudinal studies.

Review of clinical EMG studies related to muscle and occlusal factors in healthy and TMD subjects.

Abstract: Several electronic instruments have been developed as adjuncts to objectively record the dysfunctional features of temporomandibular disorders and to study the effectiveness of various treatment interventions. The aim of this review was to assess the value and contribution of clinical electromyographic research in the understanding of asymptomatic and dysfunctional muscle function and the therapeutic effects of interocclusal appliances. For this purpose MedLine and PubMed searches were conducted with the following main keywords alone and in various combinations: electromyography, muscles of mastication, masseter, temporalis, temporomandibular, TMD, utility, validity, repeatability, rest, postural, vertical dimension, occlusal, splint, treatment. The review includes critical evaluation, discussion and conclusions regarding electromyographic studies in asymptomatic and dysfunctional muscles, rest position, occlusal parameters and interocclusal appliances, as well as a critical summary and proposals for further research. Much of earlier critique of many electromyographic studies still applies regarding comparative sample selections, research designs, analyses and conclusions. The areas not well-understood include normal biological variation, capacity for adaptation, fluctuations regarding the clinical course and multidimensional features of temporomandibular disorders and long-term follow-up data, especially in studies that evaluate the effectiveness of therapeutic measures. Considering the required improvements in technical and research designs features and critical appraisal electromyographic research could have value as an adjunct research tool to study features of craniofacial muscle-related dysfunction. Until electromyographic measures are correlated with other multidimensional, especially subjective and pain-related methods, the clinical use of this method for diagnostic purposes of temporomandibular disorders remains in doubt, and is not at present recommended.

Reliability and validation of a Brazilian version of the Oral Health Impact Profile for assessing edentulous subjects

Abstract: The aims of this study were to evaluate the reliability and to validate a Brazilian version of Oral Health Impact Profile for assessing edentulous subjects (OHIP-EDENT), an inventory for measuring oral health-related quality of life of edentulous subjects. The sample comprised 65 complete denture wearers (23 men, mean age of 69.1 +/- 10.3 years). The translated OHIP-EDENT was applied on two occasions with a washout period of 3 months. Reliability was assessed by an internal consistency analysis and a test-retest approach. A preliminary validation process was conducted by a qualitative approach/interview. Results of internal consistency showed a Cronbach's alpha of 0.86 or 0.90 for the first or second appointment respectively. Through the test-retest analysis, an intra-class correlation coefficient of 0.57 was found, and individual answers reflected a broad range of agreement. Interviewed volunteers (n = 6) comprehended most questions well. In conclusion, the Brazilian version of OHIP-EDENT is adequate for assessing the oral health-related quality of life for edentulous subjects.

Influence of attachment wear on retention of mandibular overdenture.

Abstract: UNLABELLED The aims of this study were: (i) to evaluate and compare retention of two-teeth (implant) supported mandibular overdenture with either stud or magnetic attachments during linear (axial) and rotational (paraxial) dislodgements; (ii) to compare retentive properties before and after wear simulation. The test group consisted of five magnetic and four stud overdenture attachments (n = 12 specimens for each attachment type). Retention in axial direction was evaluated on one-tooth (implant) model by measuring maximum retentive force (N) and range of retention (mm) during the linear dislodgement. Retention in the paraxial direction was evaluated on mandibular-overdenture model by measuring the maximum retentive force (N) during three types of rotational dislodgements - anterior, lateral and posterior. The minimum number of cycles required to simulate wear was determined by special wear test. Afterwards, the wear was simulated in the test group, and retention in axial and paraxial directions was measured again. STATISTICAL ANALYSIS one-way anova, Scheffe post hoc and paired-samples t-tests (P < 0.05). Initially, studs had higher retention (4-11 N) than magnets (4.5-6 N) in axial direction. After the wear simulation, it had decreased from 76% to 48% for some of the studs and had become similar to the retention of magnetic attachments. Magnets had lower retention range (0.2-0.3 mm) than studs (0.5-1.1 mm). Studs provided similar or higher retention in paraxial directions than magnetic attachments both before and after wear simulation. Retentive properties of magnets decreased mostly with posterior rotational dislodgement. Retentive properties of stud overdenture attachments were less constant.

Osteoarthritis of the temporomandibular joint: an evaluation of the effects and complications of corticosteroid injection compared with injection with sodium hyaluronate.

Abstract: The purpose of this study was to compare the efficacy and the complications of intra-articular temporomandibular joint (TMJ) injections in 40 patients with osteoarthritis of the TMJ. The subjects were randomly divided into two groups, and the patients received either two intra-articular injections with sodium hyaluronate or two intra-articular injections with corticosteroids, 14 days apart. The effect of the treatment was evaluated 14 days, 1 and 6 months after the initial injection and was based on the following measurements: pain intensity, pain localization, joint sounds, mandibular function and complications. Both groups of patients had less pain intensity at the 6-month follow-up, and there was significantly less pain intensity in the group of patients receiving sodium hyaluronate compared with corticosteroids (P = 0.001). A decrease in crepitation was seen in both groups. In the 20 subjects receiving sodium hyaluronate both the mandibular vertical opening and protrusion increased significantly (P < 0.000). Lateral movement from the affected side increased both in subjects injected with sodium hyaluronate (P = 0.024), and those injected with corticosteroids (P = 0.042). In conclusion, this study confirms that injections in the TMJ with sodium hyaluronate or corticosteroids may reduce pain and improve function in patients with osteoarthritis. The injections were more effective in patients with only TMJ pain compared with patients suffering from both TMJ and myofascial pain. Injection with sodium hyaluronate was significantly more effective in decreasing pain intensity than corticosteroids. Temporary pain after injections may be observed.

The prevalence of tooth discolouration and the self-satisfaction with tooth colour in a Chinese urban population

Abstract: Summary Objectives: To determine the prevalence of tooth discolouration, self-satisfaction with tooth colour, and correlation with socio-demographic-behavioural factors in adults and teenagers in Chengdu, China. Design: A cross-sectional survey. Participants: 405 Chinese urban adults and teenagers from a multistage random probability sample. Methods: Tooth colour was measured on the maxillary central incisors using a colorimeter. Tooth discolouration was determined according to the discolouration level figure and evaluation criteria. Self-satisfaction with tooth colour was assessed on a five-point qualitative scale. Data were coded and analyzed using SPSS software. Results: The mean values for L*, a* and b* were 70·67 (s.d. 1·91), 4·29 (s.d. 2·05) and 17·51 (s.d. 4·13), respectively. Age and sex were the most important factors associated with tooth colour (P < 0·05). About half of the study population (48·9%) suffered from some tooth discolouration, and 52·6% were dissatisfied with their tooth colour. Education and smoking were significant factors affecting self-satisfaction with tooth colour (P < 0·05). Conclusions: Tooth discolouration is common among the Chinese, and many Chinese are dissatisfied with their tooth colour. Self-satisfaction with tooth colour decreased with increasing severity of discolouration. Further research is needed to determine types of tooth discolouration among broader regions in China.

Analysis of early biofilm formation on oral implants in man

Abstract: SUMMARY Biofilm formation on oral implants can cause inflammation of peri-implant tissues, which endangers the long-term success of osseointegrated implants. It has been reported previously that implants revealing signs of peri-implantitis contain subgingival microbiota similar to those of natural teeth with periodontitis. The purpose of the first part of this study was an atraumatic, quantitative investigation of biofilm formation on oral implant abutments; the objective of the second part was to investigate whether Haemophilus actinomycetemcomitans and Porphyromonas gingivalis were present in the crevicular fluid around oral implants. Biofilm formation on 14 healing abutments, inserted for 14 days in 10 patients, was analysed quantitatively by use of secondary-electron and Rutherford-backscattering-detection methods. A 16S rRNA-based polymerase chain reaction detection method was used to detect the presence of H. actinomycetemcomitans and P. gingivalis in the crevicular fluid. For this investigation, samples of sulcus fluid were collected with sterile paper points at four measurement points per abutment. The difference between biofilm coverage of supragingival surfaces (17AE5 18AE3%) and subgingival surfaces (0AE8 1AE0%) was statistically significant (P <0 AE05). By use of universal primers, bacteria were found in all the samples taken, although the two periodontal pathogens were not found in any of the samples. The absence of periodontal pathogens from the sulcus fluid during initial bacterial colonization, despite massive supragingival biofilm formation, substantiates the assumption that cellular adherence of periimplant tissue by means of hemidesmosoma, actin filaments and microvilli reduces the risk of formation of anaerobic subgingival pockets.

Effect of microwave irradiation on the flexural strength and residual monomer levels of an acrylic resin repair material.

Abstract: The degree of polymerization of an acrylic resin repair material, as established by residual monomer estimation, was compared using three different polymerization methods, i.e. bench-cure, hydroflask-cure and microwave irradiation cure. The repair strength of a conventional heat-polymerized resin was then assessed following repairs using each of these three methods. The lowest level of residual monomer was achieved with the microwave irradiation cure. It was also demonstrated that of the three methods, polymerization using microwave energy resulted in the strongest repair.

Safety and effectiveness of topical dry mouth products containing olive oil, betaine, and xylitol in reducing xerostomia for polypharmacy-induced dry mouth

Abstract: Polypharmacy is a common cause of salivary hypofunction, producing symptoms of dry mouth or xerostomia, especially among older populations. As the number of older people continues to increase, polypharmacy-induced salivary hypofunction is becoming an increasing problem. Many over-the-counter products are available for relieving symptoms of dry mouth, but few have been tested in controlled clinical investigations. The purpose of this investigation was to evaluate the safety and efficacy of a group of topical dry mouth products (toothpaste, mouth rinse, mouth spray and gel) containing olive oil, betaine and xylitol. Forty adults were entered into this single-blinded, open-label, cross-over clinical study and 39 completed all the visits. Subjects were randomly assigned at baseline to using the novel topical dry mouth products daily for 1 week, or to maintain their normal dry mouth routine care. After 1 week, they were crossed over to the other dry mouth regimen. The results demonstrated that the use of the novel topical dry mouth products increased significantly unstimulated whole salivary flow rates, reduced complaints of xerostomia and improved xerostomia-associated quality of life. No clinically significant adverse events were observed. These data suggest that the daily use of topical dry mouth products containing olive oil, betaine and xylitol is safe and effective in relieving symptoms of dry mouth in a population with polypharmacy-induced xerostomia.

The prevalence and severity of non-carious cervical lesions in a group of patients attending a university hospital in Trinidad

Abstract: Summary Non-carious cervical lesions (NCCLs) are often encountered in clinical practice and their aetiology attributed to toothbrush abrasion, erosion and tooth flexure. This paper aims to determine the prevalence and severity of NCCLs in a sample of patients attending a university clinic in Trinidad and to investigate the relationship with medical and dental histories, oral hygiene practices, dietary habits and occlusion. Data were collected via a questionnaire and clinical examination. Odds ratios were used to determine the association of the presence of lesions and the factors examined. One hundred and fifty-six patients with a mean age of 40·6 years were examined of whom 62·2% had one or more NCCLs. Forty five per cent of the lesions were sensitive to compressed air. Younger age groups had a significantly lower correlation with the presence of NCCLs than older age groups. Other significant factors included patients who reported heartburn, gastric reflux, headaches, bruxism, sensitive teeth and swimming or had a history of broken restorations in the last year. There was also significant correlation of NCCLs in patients who brushed more than once a day or used a medium or hard toothbrush. Patients with vegetarian diets and those who reported consuming citrus fruits, soft drinks, alcohol, yoghurt and vitamin C drinks were associated with the presence of lesions. Significant associations were also found in patients with group function, faceting, clicking joints or those who wore occlusal splints.

The evaluation of direct composite restorations for the worn mandibular anterior dentition – clinical performance and patient satisfaction

Abstract: This prospective split-mouth clinical trial evaluated the performance and patient satisfaction of 168 Herculite XRV direct composite restorations bonded to the worn anterior dentition of 18 patients with localized anterior tooth surface loss. One hundred and six of these restorations were placed on the mandibular anterior teeth. The restorations increased the anterior occlusal vertical dimension between 0.5 and 5 mm and the posterior occlusal contacts were restored after a mean duration of 6.2 months (range: 3-13 months) in 14 out of the 15 'Dahl' sub-group patients. The restorations were evaluated after 2.5 years of service by five examiners. Four patients and 23 mandibular restorations were lost to follow-up. Multiple clinical and restorative variables were assessed to determine their influence on restoration performance. Complete failure occurred in 6% of the restorations. Circumferential preparation and height of the restorative addition did not influence the performance of the restorations. A Visual Analogue Scale (VAS) was used to assess the patient's opinion regarding sensitivity, aesthetics, longevity and function of the worn mandibular anterior teeth. A statistically significant difference (95% CI) was found between the pre-operative and 1-month review VAS responses for aesthetics and longevity and this was maintained at the 2.5-year review. Direct composite restorations placed at an increased occlusal vertical dimension are a simple and time-efficient method of managing the worn mandibular anterior dentition. Patient's acceptance and adaptation to the technique is good and the results are accompanied with a high level of patient satisfaction that is maintained for the medium-term.

Fracture strength of four-unit Y-TZP FPD cores designed with varying connector diameter. An in-vitro study.

Abstract: Summary Reported clinical success rates of all-ceramic fixed partial dentures (FPDs) made of high-strength oxide ceramics range between 82·5% and 100%. The main cause of all-ceramic FPD failure is fracture in the connector area. There is, however, no consensus on what connector dimensions are adequate. The aim of this in-vitro study was, therefore, to compare the fracture strength of four-unit Y-TZP FPD cores designed with different connector diameters. A total of 40 four-unit FPD cores supported by end abutments and having two pontics were manufactured in Procera® Zirconia. Five groups of FPD cores with connector dimensions of 2·0, 2·5, 3·0, 3·5 and 4·0 mm were produced. All FPD cores underwent a firing programme according to the manufacturer’s recommendations for the veneering porcelain, a cyclic preload, thermocycling and finally, load until fracture. Fracture strength was significantly higher for each increase in connector diameter except for the 2·0-mm and 2·5-mm diameters where all fractures occurred during preload. All FPD cores fractured in the connector area. Within the limitations of this in-vitro study, a minimum diameter of 4·0 mm is recommended for all-ceramic zirconia-based FPDs with long spans or replacing molars. Clinical studies are, however, needed to determine adequate connector dimensions.

Precision of in vivo spectrophotometric colour evaluation of natural teeth

Abstract: The aim of the study was to evaluate the precision of a reflectance spectrophotometer during longitudinal assessment of tooth colour in vivo. The spectrophotometric data of five standardized circular areas on the labial surfaces of six teeth (four upper and two lower), from 22 dental students, were recorded on three separate days (1st, 3rd and 30th) employing a repeated-measuring design (n = 3). Total colour differences were calculated according to the equation DeltaEpsilon = [(DeltaL*)(2) + (Deltaa*)(2) + (Deltab*)(2)](1/2). It was found that all measured teeth areas, recorded by the same examiner (DeltaEpsilon(INTRA)), demonstrated minor colour changes during the three different time intervals, which did not exceed in every case the 50:50% perceptibility threshold of DeltaEpsilon = 1, thus indicating a good match. The smallest DeltaEpsilon values were recorded for the upper central incisors, whereas lower central incisors and upper first premolars revealed the most significant colour differences (0.68 +/- 0.21 and 0.70 +/- 0.25 DeltaEpsilon-units, respectively). The central zone of the middle third of each labial tooth surface exhibited the most precise recordings. With regard to interexaminer reproducibility (DeltaEpsilon(INTER)), the mesial and distal areas of all measured teeth presented the most statistically significant colour differences (0.48 +/- 0.15 and 0.50 +/- 0.17 DeltaEpsilon-units, respectively). It is concluded that the spectrophotometer tested in the present study can provide a precise measurement of tooth colour in vivo. However, in rejection of the null hypothesis, the type (posterior teeth, mandibular incisors) and the mesial and distal areas of natural teeth affected the repeatability and reproducibility of intraoral spectrophotometric measurements.

Dental endosseous implants in the medically compromised patient

Abstract: The literature contains numerous observations on the significance of systemic disorders as contraindications to dental endosseous implant treatment, but the justification for these statements is often apparently allegorical. Although implants are increasingly used in healthy patients, their appropriateness in medically compromised patients is less equivocal. Perhaps surprisingly, the evidence of their efficacy in these groups of patients is quite sparse. Indeed, there are few if any randomized controlled trials (RCTs) in this field. Furthermore, any health risks from the placement of implants are unclear. We review the current evidence for the risks associated with endosseous implants in a range of systemic disorders. There is clearly a need for prospective systematic trials. The degree of disease-control may be far more important that the nature of the disorder itself, and individualized assessment, including the medical condition, quality of life and life expectancy is indicated. The benefits of implants to many of these patients may outweigh any risks. However, proper informed consent is mandatory.

Effect of implant support on distal extension removable partial dentures: in vitro assessment

Abstract: The implants in implant-supported removable partial dentures (RPDs) are placed in the edentulous ridge to stabilize the RPD and minimize the resultant rotational movement. This study investigated the effect of implant placement on RPD stability. A model simulating a mandibular bilateral distal extension missing was fabricated using epoxy resin and silicone impression material as thin (1 mm) and thick (2 mm) soft tissues. Five pressure sensors (PS-10K, Kyowa, Tokyo, Japan) were attached near the left and right first molars (#36 and #46), first premolars (#34 and #44) and medio-lingual alveolar crest. Five bilateral distal extension RPDs with Co-Cr frameworks were conventionally fabricated. After the implants were placed at the bilateral second molar areas, healing caps (4.5 mm high) were connected to the denture base with autopolymerized resin to support the RPD. As in a conventional RPD, sealing screws were placed without connecting them. Loads up to 5 kg were applied, and the pressure and displacement of the RPDs (n = 5) were simultaneously measured and analysed using the Wilcoxen test (alpha = 0.05). There was less pressure on both thin and thick soft tissues, the #36, #46 and the medio-lingual alveolar crest from the implant-supported RPD than from the conventional RPD (P 0.05). There was significantly less denture displacement of the implant-supported RPD than of the conventional denture (P < 0.05). Implant support helped prevent the displacement of distal extension RPDs and decreased the pressure on soft tissues.

New method for evaluation of tongue-coating status.

Abstract: The purpose of this study was to determine the viability of Tongue Coating Index, which is a new method for evaluating tongue-coating status. To determine the reliability and reproducibility of our new evaluation criteria (Score 0: Tongue coating not visible; Score 1: Tongue coating thin, papillae of tongue visible; Score 2: Tongue coating very thick, papillae of tongue not visible), 10 observers evaluated 20 photographs of tongues. Each tongue surface was divided into nine sections. Observers evaluated each section according to our new criteria and each score for tongue-coating status was recorded in the pertinent section of the Tongue Coating Record form. They repeated the same evaluation 2 weeks after the first evaluation. The relationship between the scores obtained and number of oral microorganisms was investigated in 50 edentulous patients. Tongue coating was collected from the tongue surface after evaluation of tongue-coating status. The total number of anaerobic bacteria and the number of Candida species were counted from the specimens collected. Interobserver agreement and intraobserver agreement were 0.66 and 0.80 by Cohen's kappa, respectively. No significant difference was observed in the number of Candida species among the three scores. The number of total anaerobic bacteria, however, was significantly different among the scores (P < 0.05). Therefore, we conclude that our method for evaluating tongue-coating status offers new criteria that are superior in reliability and reproducibility, and that also reflect the total number of anaerobic bacteria present on the dorsum of the tongue.

Relationship between salivary flow rate and clinical symptoms and behaviours in patients with dry mouth.

Abstract: The purpose of this study was to investigate the relationship between whole salivary flow rate and dry mouth-related subjective symptoms and behaviours in patients with dry mouth. Seventy-eight patients (13 men and 65 women, 58.2 +/- 13.5 years) with dry mouth were asked a standardized series of questions concerning dry mouth-related symptoms and behaviours. Whole salivary flow rates were measured under unstimulated and stimulated conditions. The effect of oral dryness on daily life was significantly associated with the flow rate of stimulated whole saliva (r(s) = -0.30, P < 0.01) and frequency of oral dryness (r(s) = 0.46, P < 0.01). Dry mouth-related symptoms and behaviours were significantly associated with the whole salivary flow rate and the correlation was more remarkable with respect to stimulated whole saliva. The most common dry mouth-associated complaint was sensation of burning mouth. The effect of oral dryness on daily life was significantly affected by the presence of taste disturbances. Collectively, dry mouth-related symptoms and behaviours were significantly associated with whole salivary flow rate. Moreover, the severity of dry mouth-related symptoms was more closely correlated with the flow rate of stimulated saliva, compared with the unstimulated flow rate.

Comparison of shade matching by visual observation and an intraoral dental colorimeter

Abstract: The purpose of this study was to compare the applicability of two shade-matching approaches: Vintage Halo shade guide (visual method) and Shofu ShadeEye NCC colorimeter (instrumental method). Twenty participants' maxillary left central incisors were evaluated. Corresponding metal ceramic crowns were fabricated with each shade-matching approach. The colour distributions (L*, a* and b*) of the middle third region of each tooth and corresponding metal ceramic crowns were spectrophotometrically assessed. The colour difference (DeltaE) and colour distributions (DeltaL*, Deltaa* and Deltab*) between the tooth and the corresponding crowns were calculated. We found that the colour differences of both groups fell within the clinical unacceptable range (DeltaE > 2.75). Regarding DeltaE and the three colour distributions, no significant difference was found, expect for a* (P < 0.01). The shade matching difficulty degree was analysed through the agreements of visual shade selection. Within easy matching cases, the instrumental method achieved better results (P = 0.041). In conclusion, it is suggested that the reliability of shade matching can be ensured by neither the colorimeter nor the visual approach. However, the colorimeter can achieve better results within easy matching cases.

A preliminary report of patients treated with early loaded implants using computerized tomography-guided surgical stents: flapless versus conventional flapped surgery.

Abstract: The objective of this clinical study was to compare the survival rates of early loaded implants placed using flapless and flapped surgical techniques and to determine the bone density in the implant recipient sites using computerized tomography (CT). The study population consisted of 12 patients who were referred implant placement. One group consisted of five patients referred for the placement of 14 implants and treated with a flapless procedure. The other group consisted of seven patients referred for the placement of 45 implants with a conventional flapped procedure. Patients were selected randomly. CT machine was used for pre-operative evaluation of the jaw bone and the mean bone density value of each implant recipient site was recorded in Hounsfield units (HU). All implants were placed using CT-guided surgical stents. The early loading protocols included 2 months of healing in the mandible and 3 months of healing in the maxilla. Single-implant crowns, implant-supported fixed partial dentures, and implant-retained over dentures were delivered to the patients. Of 59 implants placed, one was lost in the conventional flapped group within the first month of healing, meaning overall implant survival rate of 98.3% average 9 months later. The highest average bone density value (801 +/- 239 HU) was found in the anterior mandible, followed by 673 +/- 449 HU for the posterior maxilla, 669 +/-346 HU for the anterior maxilla and 538 +/- 271 HU for the posterior mandible. The results of this study show that the early loading of implants placed utilizing flapless surgical technique with CT-guided surgical stents may be possible.

Osseointegration of anodized titanium implants under different current voltages: a rabbit study

Abstract: The oxide layer that covers a titanium surface is extremely stable and appears to have excellent biocompatibility, which can result in successful osseointegration. The aim of this study was to analyse the characteristics of an oxide layer formed by anodic oxidation (anodization), and to evaluate the extent of bone healing around the anodized implant. The screw-type implants were made of commercially pure titanium (Grade 2). The Group 1 samples had a turned surface, and three other types of experimental specimens were anodized under constant voltages of 190 V (Group 2), 230 V (Group 3) and 270 V (Group 4). The surface characteristics of each sample type were inspected. Removal torque was measured after a 4-week healing period and the histomorphometric analysis was performed 6 weeks after implantation in rabbit tibiae. There was an increase in both the size and number of pores as the anodizing voltage increased. The Ra value of the Group 4 samples was higher than those in the Group 1 and 2 samples (P < 0.05). Group 3 showed a difference compared with Group 1 (P < 0.05). A thicker oxide layer, which contained crystalline (anatase) TiO(2) with the inclusion of some electrolytes (Ca, P), was formed at the higher anodizing voltage. Group 4 had higher removal torque values and percentages of bone-to-implant contact than the other groups (P < 0.05). The anodized titanium implants showed more intimate and stronger connections with peri-implant bone during early osseointegration than the turned titanium implants in this experimental model.

ZrO2 three-unit fixed partial dentures: comparison of failure load before and after exposure to a mastication simulator.

Abstract: This study evaluated the failure load of different zirconia-based all-ceramic fixed partial dentures (FPD) before and after artificial aging. Forty-eight zirconia frameworks for three-unit FPDs were fabricated using different manufacturing systems [(DCS), Procera (Nobel Biocare) and Cerec inLab (Sirona)], veneered using Vita VM9 (Vita Zahnfabrik) opaque ceramic and conventionally cemented on human teeth. The restorations were divided according to the system used for manufacturing the frameworks into three groups of 16 specimens each (DCS, Procera and Vita YZ-Cerec). Half of each group was artificially aged through dynamic loading and thermal cycling, whereas, the other half was not subjected to artificial aging. Subsequently, all specimens were loaded occlusally until fracture occurred using a universal testing machine. Pair-wise Wilcoxon rank tests were performed to test for differences in failure loads at a statistical significance level of 0.05. All specimens subjected to artificial aging survived with no failures. The median (IQR=x0.25-x0.75) failure loads (N) before and after artificial aging were, respectively, as follows: group DCS, 2131 (1948-2239) and 1797 (1590-2074); group Procera, 1684 (1615-1873) and 1394 (1275-1495); and group Vita YZ-Cerec, 1845 (1621-1923) and 1625 (1521-1747). No significant differences were found for comparisons between different groups before artificial aging. After artificial aging, group Procera showed significantly smaller values than group DCS (P=0.042). All tested restorations have the potential to withstand occlusal forces applied in the posterior region and can therefore represent interesting alternatives to replace metal-ceramic restorations. Further assessments are needed before recommending these restorations for daily practice.

Individuals’ perception of oral health and its impact on the health‐related quality of life

Abstract: summary This research divides oral health status into two parts: clinical disease and patients’ subjective perceptions, and then discusses what impact these two items have on the health-related quality of life. A total of 1600 elderly persons, over 65 years old, were sampled as the research target. The overall response rate was 71·62%. SF-36 was used to measure the health-related quality of life, Oral Health Impact Profile (OHIP) was used to measure individuals’ subjective perception of their oral health status, and the number of natural teeth was considered as the clinical issue. There are 12 items which affect quality of life in the physical aspect, namely: OHIP score; age; gender; weekly frequency of social activities and interactions; financial status; physician visits per month on a regular basis; hospitalization during the last 6 months; arthritis, rheumatism, cardiovascular disease or diabetes; abnormal IADL patients; and the satisfaction level of current lifestyle. Factors affecting quality of life (i.e. mental aspects), are few, including: OHIP score, gender, education level, weekly frequency of social activities and interactions and satisfaction level of current lifestyle. The results indicate that individuals’ subjective perceptions of their oral health status had a greater impact, than did the clinical issue, on their health-related quality of life. The outcomes and findings derived from this research may provide alternative perspectives for professionals, so that they may be more careful concerning individuals’ subjective perceptions.