Randomised controlled trial on testing an increased vertical dimension of occlusion prior to restorative treatment of tooth wear.

BACKGROUND: Evaluation of a new vertical dimension of occlusion (VDO) in complex restorative treatments is considered a necessary step prior to placement of restorations. OBJECTIVES: This randomised controlled trial (RCT) aimed to assess the effects of using an evaluation of a VDO increase before restorative treatment in patients with moderate-to-severe tooth wear, on OHRQoL, freeway space (FWS) and interventions to restorations. METHODS: Forty-two patients with tooth wear were included and randomly allocated to either a test phase with a Removable Appliance (RA) or no test phase. Restorative treatment consisted of restoration of all teeth using composite restorations in an increased VDO. OHIP-score, freeway space (FWS) and clinical acceptability of restorations were assessed at baseline and at recall appointments (1 month and 1 year). Intervention to restoration was scored in case of material chipping or when the abutment tooth had increased sensitivity that could be linked to occlusal overloading. ANCOVA analyses, Univariate Cox regression, t-tests and descriptive analyses were performed (p < .05). RESULTS: Clinical follow-up after 1 year was completed for 41 patients. No significant effect of testing the VDO with a RA could be found on the OHIP-score (p = .14). Reduction of FWS in the RA group, compared to the control group, was significantly lower at 1 year (p = .01, 95% CI -1.09 to -0.15). No effect on early interventions to restorations was found (p = .94). CONCLUSION: This RCT showed that a removable appliance is not indicated to functionally test the increased VDO prior to restorative treatment in patients with tooth wear.

Rehabilitation of Worn Dentition with CAD-CAM Restorations: A Case Report.

PURPOSE: To describe the digital workflow applied for restoring a severely worn dentition with minimally invasive CAD/CAM resin nano-composite restorations. MATERIALS AND METHODS: A 40-year-old male in good general health and with full-arch dentition suffered from dentin hypersensitivity and wanted to improve the esthetics of his worn anterior teeth. The dental wear can be described as general, grade 3, according to the Tooth Wear Index,27 with more wear in maxillary than in mandibular teeth. Signs and symptoms were typical for a chemical type of wear, with some mechanical wear also apparent. No functional problems, eg, impaired chewing, were present. On the OHIP-49 questionnaire, the patient expressed a reduced quality of life. The goal of the treatment was to reconstruct the anatomical form of the teeth as far as possible, thereby also improving quality of life. Due to the rather large volume of lost tooth tissue per tooth, indirect treatment using CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) was applied. RESULTS: The seating of the CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) restorations was considered precise. CONCLUSION: In the treatment of severe tooth wear, the described digital workflow using CAD/CAM restorations for occluding restorations and direct composite materials in the esthetic zone is a potential treatment modality that is workable and minimally invasive.

Prospective Study on CAD/CAM Nano-Ceramic (Composite) Restorations in the Treatment of Severe Tooth Wear.

PURPOSE: The aim of this prospective study was to evaluate the clinical performance of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in patients with severe tooth wear, the effect of the restorative treatment on the oral health-related quality of life (OHRQoL), and the etiology of tooth wear as a risk factor for restoration failure. MATERIALS AND METHODS: Patients with generalized severe tooth wear were included. Restorations (LAVA Ultimate, 3M Oral Care) were cemented (RelyX Ultimate, 3M Oral Care) on all teeth and were evaluated after 1 month and 1 year. OHRQoL was assessed via questionnaires at baseline and after 1 year. Differences were evaluated (paired t-test). Two mechanical tooth-wear lesions resulting from tooth-tooth contact, and 3 chemical tooth wear lesions resulting from intrinsic or extrinsic acids dissolving natural hard tooth substance, were evaluated to assess the etiology of tooth wear in association with restoration failure using multilevel logistic regression analyses (p < 0.05). RESULTS: Twenty-one patients (age: 41.7 ± 10.4 years) were evaluated after 1 year (13.5 ± 1.2 months). 568 indirect CAD/CAM restorations were placed. None were replaced or lost. Twelve were repaired and 10 were refurbished. Success rates were 100% to 97.2%. Questionnaires showed a significant positive impact of the treatment on OHRQoL (p < 0.001). The presence of mechanical lesions did not pose a higher risk for restoration failure (p = 0.78). The presence of chemical lesions showed a lower risk of restoration failure (p = 0.002). CONCLUSION: The use of minimally invasive, CAD/CAM nano-ceramic (composite) restorations in the restorative treatment of severely worn dentitions showed satisfactory results in the short term.

Survival of Restored Endodontically Treated Teeth in Relation to Periodontal Status.

The aim of the present study was to investigate the success and survival of restored endodontically treated teeth (ETT) in a general practice environment related to periodontal parameters. Data from 360 restored ETT treated between 2000 and 2011 were collected. Dates of interventions like restorations, repairs, replacements and extractions were recorded. Additionally, general information about patients and dentitions as well as periodontal status was recorded. Success was analyzed using Kaplan-Meier statistics and a multivariate Cox regression analysis was performed to assess variables influencing success and survival. After a mean observation time of 4.34 years (range 0.6 - 11.6 years), 19 teeth were extracted and 27 restorations needed repair or replacement. According to the Cox regression, increasing maximum pocket depth of the tooth resulted in a higher risk for failure (p=0.012). In conclusion, periodontal pocket depth was found to be a significant factor in the survival of restored ETT.

Survival of Restored Endodontically Treated Teeth in Relation to Periodontal Status

Abstract The aim of the present study was to investigate the success and survival of restored endodontically treated teeth (ETT) in a general practice environment related to periodontal parameters. Data from 360 restored ETT treated between 2000 and 2011 were collected. Dates of interventions like restorations, repairs, replacements and extractions were recorded. Additionally, general information about patients and dentitions as well as periodontal status was recorded. Success was analyzed using Kaplan-Meier statistics and a multivariate Cox regression analysis was performed to assess variables influencing success and survival. After a mean observation time of 4.34 years (range 0.6 - 11.6 years), 19 teeth were extracted and 27 restorations needed repair or replacement. According to the Cox regression, increasing maximum pocket depth of the tooth resulted in a higher risk for failure (p=0.012). In conclusion, periodontal pocket depth was found to be a significant factor in the survival of restored ETT.

Resumo O objetivo do presente estudo foi investigar a taxa de sucesso e de sobrevivência de dentes restaurados e tratados endodonticamente (DTE) em uma clínica privada e relacionar com índices periodontais. Dados de 360 restaurações realizadas em DTE realizadas entre 2000 e 2011 foram coletados. As datas das intervenções, como restaurações, reparos, substituições e extrações foram registradas. Ainda, informações gerais relacionadas aos pacientes, aos dentes envolvidos e ao estado periodontal foram também coletadas. A taxa de sucesso foi analisada utilizando o método estatístico Kaplan-Meier e uma análise multivariada do tipo regressão de Cox foi realizada para avaliar variáveis que influenciaram na taxa de sucesso e de sobrevivência. Depois de um período de observação médio de 4,34 anos (0,6-11,6 anos), 19 dentes foram extraídos e 27 restaurações precisaram de reparo ou substituição. De acordo com a regressão de Cox, o aumento na profundidade de bolsa periodontal do dente resulta em um maior risco de falha (p=0,012). Em conclusão, a profundidade de bolsa periodontal foi considerada como um fator significativo na sobrevivência de dentes restaurados e tratados endodonticamente.

Shear resistance of fiber-reinforced composite and metal dentin pins.

PURPOSE: To assess whether dentin pins increase shear resistance of extensive composite restorations and to compare performance of mini fiber-reinforced composite (FRC) anchors with metal dentin pins in the laboratory. METHODS: 30 extracted sound molars were randomly divided into three groups. Occlusal surfaces were ground flat with a standard surface area and resin composite restorations were made in Group A. In Groups B and C similar restorations were made, with additionally four metal pins placed in Group B and four FRC pins in Group C. Specimens were statically loaded until failure occurred. Failure modes were characterized as intact remaining tooth substrate (adhesive or cohesive failure of restoration) or fractured remaining tooth substrate. RESULTS: Mean failure stresses were 6.5 MPa (SD 3.2 MPa) for Group A, 9.7 MPa (SD 2.6 MPa) for Group B and 9.2 MPa (SD 2.6 MPa) for Group C. Difference in mean failure stresses between Group A and Groups B and C was statistically significant (P = 0.01), while the difference between Groups B and C was not (P = 0.63). Failures of the restoration without fracture of tooth substrate were seen for 80% of specimens in Group A and 20% in Groups B and C (P = 0.04).

Assessment of early attrition using an ordinary flatbed scanner.

UNLABELLED: The aim of this study was to assess a two-dimensional method to monitor occlusal tooth wear quantitatively using a commercially available ordinary flatbed scanner. MATERIALS AND METHODS: A flatbed scanner, measuring software and gypsum casts were used. In Part I, two observers (A and B) independently traced scans of marked wear facets of ten sets of casts in two sessions (test and retest). In Part II, three other sets of casts were duplicated and two observers (C and D) marked wear facets and traced the scanned images independently. Intra- and inter-observer agreement was determined comparing measured values (mm(2)) in paired T-tests. Duplicate measurement errors (DME) were calculated. RESULTS: In Part I the test and retest values (10 casts, 218 teeth) of observer A and B did not differ significantly (A: p = 0.289; B: p = 0.666); correlation coefficients were 0.998 (A) and 0.999 (B). "Tracing wear facets" showed a DME of 0.30 mm(2) for observer A and 0.15 mm(2) for observer B. In Part II, assessment of 70 teeth resulted in correlation coefficients of 0.994 for observer C and 0.997 for observer D; no differences between test and retest values were found for C (p = 0.061), although D differed significantly (p = 0.000). The DME for "marking and tracing wear facets" was 0.39 mm(2) (C) and 0.27 mm(2) (D). DME for inter-observer agreement were 0.45 mm(2) (test) and 0.42 mm(2) (re-test). CONCLUSION AND CLINICAL RELEVANCE: We conclude that marking and tracing of occlusal wear facets to assess occlusal tooth wear quantitatively can be done accurately and reproducibly.

In vitro repair of fractured fiber-reinforced cusp-replacing composite restorations.

Objective. To assess fracture resistance and failure mode of repaired fiber-reinforced composite (FRC) cusp-replacing restorations. Methods. Sixteen extracted human premolars with fractured cusp-replacing woven (Group (A)) or unidirectional (Group (B)) FRC restorations from a previous loading experiment were repaired with resin composite and loaded to fracture. Results. Differences in fracture loads between groups were not statistically significant (P = 0.34). Fracture loads of repaired specimens were significantly lower than those of original specimens (P = 0.02 for Group (A) and P < 0.001 for Group (B)). Majority of specimens showed failure along the repaired surface. In Group (B) 89% of specimens showed intact tooth substrate after restoration fracture, while this was 28% in Group (A) (P = 0.04). Conclusion. Fractured cusp-replacing FRC restorations that are repaired with resin composite show about half of fracture resistance of original restorations. Mode of failure with a base of unidirectional fibers is predominantly adhesive.

Clinical performance of direct composite restorations for treatment of severe tooth wear.

PURPOSE: The aim of this retrospective clinical study was to evaluate the performance of direct composite restorations that were placed in patients with severe tooth wear requiring an increase of the occlusal vertical dimension. METHODS AND MATERIALS: Eighteen patients with severe tooth wear, who had been treated in a private practice between April 1996 and July 2007, were selected. All subjects had been treated with direct composite resin restorations in increased vertical dimension using a three-step etch-and-rinse adhesive system and a hybrid composite resin. From the dental records, information about re-intervention and replacement of restorations was obtained. Patients were then clinically examined to evaluate the status of the restorations and interviewed about their satisfaction with the restorative treatment using a Visual Analogue Scale (VAS). RESULTS: Eighteen patients (16 male, 2 female with an average age of 44.8 years) with severe tooth wear were included in the study. Time since treatment ranged from 6 months to 12 years and the mean observation time was 3.98 years. Of the 332 restored teeth, 23 restorations showed failures (6.9%). Eight restorations (2.4%) showed major fractures, 11 restorations (3.3%) showed minor fractures, and four restorations (1.2%) failed due to secondary caries. VAS data on a scale of 0 to 10 revealed high patient satisfaction with this type of restoration (mean 9.0). CONCLUSION: Treatments with direct hybrid composite restorations placed in an increased occlusal vertical dimension showed good clinical performance in patients with severe tooth wear.

Body position and occlusal contacts in lateral excursions: a pilot study.

This pilot study aimed to explore whether occlusal contacts during lateral excursions are influenced by tilted body positions. Occlusal contacts in lateral excursions were verified for 30 dental students and 22 dental staff members using articulation foil while patients were seated in a dental chair. The number and location of dynamic tooth contacts (initial and halfway) were registered with the back of the dental chair in three positions: upright, 45 degrees, and supine. For the majority of subjects (96%), dynamic occlusal contacts changed when the body position was altered.

Five-year survival of 3-unit fiber-reinforced composite fixed partial dentures in the posterior area.

OBJECTIVES: The purpose of this clinical study was to evaluate the long-term outcome of three-unit posterior fixed partial dentures (FPDs) made of fiber-reinforced resin composite (FRC), and to identify design factors influencing the survival rate. METHODS: 77 patients (52 females, 25 males) received 96 indirectly made FRC FPDs, using pre-impregnated unidirectional glass-fibers, requiring manual wetting, as framework material. FPDs were surface (n=31) inlay (n=45) or hybrid (n=20) retained and mainly located in the upper jaw. Hybrid FPDs consisted of a wing retainer at canine and an inlay retainer at distal abutment tooth. Surface FPDs consisted of uplay and wing combinations. Follow-up period was at minimum 4.5 years, with checkups at every 1-2 years. The study was carried out by six operators in three centers in the Netherlands, Finland and Sweden. Survival rates, including reparable defects of FPDs, and success rates were determined. RESULTS: Kaplan-Meier survival rate at 5 years was 71.2% (SE 4.8%) for success and 77.5% (SE 4.4%) for survival. Differences were not significantly different. Main failure modes were delamination and fracture of the FPD. Only FPDs with surface retainers showed debonding. CONCLUSIONS: A success rate of 71% and a survival rate of 78% after 5 years was found. Survival rates of inlay, hybrid and surface retained FPDs did not significantly differ.

Replacement of missing teeth in a southern region of Vietnam--a descriptive dental laboratory study.

AIM: To explore whether tooth replacement in a southern region of Vietnam is in line with the primary health care approach, aiming at health services for all people at affordable costs. METHODS: Tooth replacement was investigated by means of prostheses as delivered by four dental laboratories of which the output was considered representative. Information was based on dental casts related to the prostheses. RESULTS: Prostheses replaced almost all missing teeth, irrespective of the types (interrupted or shortened dental arches) and numbers of missing teeth in the dental arch they were made for. Acrylic removable partial dentures were the most common prostheses delivered (65% of removable partial dentures). CONCLUSION: It cannot be stated that dental arch conditions in this study were representative for the southern Vietnamese population. However, it is concluded that dental practitioners tend to provide complete dental arches by tooth replacements. This morphologically based approach might introduce over treatment. In line with primary oral health care, a functionally oriented treatment management, including the shortened dental arch concept, should be implemented.

Five-year survival of 3-unit fiber-reinforced composite fixed partial dentures in the anterior area.

OBJECTIVES: The purpose of this clinical study was to evaluate the long-term outcome of 3-unit anterior fixed partial dentures (FPDs) made of fiber-reinforced resin composite (FRC), and to identify design factors influencing the survival rate. METHODS: 52 patients (26 females, 26 males) received 60 indirectly made FRC FPDs, using pre-impregnated unidirectional glass fibers, requiring manual wetting, as framework material. FPDs were surface (n=48) or hybrid (n=12) retained and mainly located in the upper jaw. Hybrid FPDs had a combination of retainers; i.e. crown at one and surface retention at the other abutment tooth. Surface FPDs were either purely adhesively retained (n=29) or with additional mechanical retention (n=19). Follow-up period was at minimum 5 years, with check-ups every 1-2 years. Six operators were involved, in three centers in the Netherlands, Finland and Sweden. Survival rates, including repairable defects of FPDs, and success rates were determined. RESULTS: Kaplan-Meier survival rate at 5 years was 64% (SE 7%). For the level of success, values were 45% (SE 7%) and the estimated median survival time 58 (SE 10.1) months. For surface FPDs, additional mechanical retention did not improve survival significantly. There was a trend towards better survival of surface FPDs over hybrid FPDs, but differences were not significant. Main failure modes were fracture of the FPD and delamination of veneering composite. SIGNIFICANCE: A success rate of 45% and a survival rate of 64% after 5 years was found. Fracture of the framework and delamination are the most prevalent failure modes, especially for surface FPDs.

Prevalence of tooth wear in adults.

PURPOSE: The aim of this study was to investigate data on the prevalence of tooth wear in adults and assess possible correlations using a systematic review. MATERIALS AND METHODS: A search of the literature, using PubMed and the Cochrane Library, from January 1980 to July 2007 was made using keywords "tooth + wear"; "dental + attrition + prevalence"; "dental + wear + prevalence"; "erosion + prevalence"; and "abrasion + prevalence". References were independently screened for inclusion and exclusion by two investigators and Cohen Kappa was used as the measure of agreement. Data were collected and converted into the Smith and Knight Tooth Wear Index. RESULTS: One hundred eighty-six references were initially selected and subjected to the systematic review procedure; 13 survived the inclusion procedure. Four articles were suitable for regression analysis at tooth level (R2 = .593) and 3 at subject level (R2 = .736), using "age and age squared" and "age squared" as variables, respectively. Six studies reported males having significantly more tooth wear than females. CONCLUSION: The predicted percentage of adults presenting with severe tooth wear increases from 3% at the age of 20 years to 17% at the age of 70 years. Increasing levels of tooth wear are significantly associated with age.

Microhardness of resin composite materials light-cured through fiber reinforced composite.

OBJECTIVES: To compare polymerization efficiency of resin composite basing materials when light-cured through resin composite and fiber reinforced composite (FRC) by testing microhardness. METHODS: Simulated indirect restorations were prepared by application of resin composite (Clearfil AP-X) or FRC (EverStick) to nylon rings with 1.5mm thickness and 8mm diameter, followed by light-curing. Resin composite basing material (Clearfil Majesty Flow or Clearfil AP-X) was applied to identical rings and light-cured through the simulated indirect restorations with exposure times of 20, 40, or 60s. Light-curing though a ring without resin material (=no indirect restoration) served as control. For each combination of basing material and indirect restoration 10 specimens were prepared for each exposure time. Top and bottom surface Vickers microhardness numbers (VHNs) of basing materials were recorded after 24h. RESULTS: After 60s exposure time, VHNs with indirect FRC were not different from control VHNs, while VHNs with indirect resin composite were significantly lower (p<0.001). Linear regression analysis revealed that resin composite basing material used had the greatest effect on top and bottom VHNs (p<0.001). The presence of an indirect restoration resulted in decreased VHNs (p<0.001), with resin composite resulting in lower VHNs when compared to FRC. Moreover, a longer exposure time resulted in increased VHNs (p<0.001). SIGNIFICANCE: Results suggest that polymerization of resin composite basing materials is more effective when light-curing through an FRC than through a resin composite indirect restoration. Prolonging of exposure time, however, is necessary when compared to light-curing without presence of indirect restoration material.

Clinical studies of fiber-reinforced resin-bonded fixed partial dentures: a systematic review.

In the past decade, follow-up studies on fiber-reinforced composite fixed partial dentures (FRC FPDs) have been described. Combining the results of these studies to draw conclusions about the effectiveness of FRC FPDs is challenging. The objective of this systematic review was to obtain survival rates of FRC FPDs and to explore the relationships between reported survival rates and risk factors. In a literature-selection procedure on the clinical performance of FRC FPDs, 15 studies, reporting on 13 sets of patients, were analyzed. The Kaplan-Meier estimate of the overall survival, based on the data from all sets of patients (n = 435) was 73.4% (69.4-77.4%) at 4.5 yr. Converted survival rates at 2 yr of follow-up showed substantial heterogeneity between studies. It was not possible to build a reliable regression model that indicated risk factors. The technical problems most commonly described were fracture of the FPD and delamination of the veneering composite.

Fiber-reinforced dental composites in beam testing.

OBJECTIVES: The purpose of this study was to systematically review current literature on in vitro tests of fiber-reinforced composite (FRC) beams, with regard to studies that followed criteria described in an International Standard. The reported reinforcing effects of various fibers on the flexural strength and elastic modulus of composite resin beams were analyzed. SOURCES: Original, peer reviewed papers, selected using Medline from 1950 to 2007, on in vitro testing of FRC beams in comparison to non-reinforced composite beams. Also information from conference abstracts (IADR) was included. DATA: With the keywords (fiber or fibre) and (resin or composite) and (fixed partial denture or FPD), the literature search revealed 1427 titles. Using this strategy a broad view of the clinical and non-clinical literature on fiber-reinforced FPDs was obtained. Restricting to three-point bending tests, 7 articles and 1 abstract (out of 126) were included. Finally, the data of 363 composite beams were analyzed. The differences in mean flexural strength and/or modulus between reinforced and unreinforced beams were set out in a forest plot. Meta-regression analyses were performed (single and multiple regression models). CONCLUSIONS: Under specific conditions we have been able to show that fibers do reinforce resin composite beams. The flexural modulus not always seems to increase with polyethylene-reinforcement, even when fibers are located at the tensile side. Besides, fiber architecture (woven vs. unidirectional) seems to be more important than the type of fiber for flexural strength and flexural modulus.

Composite resin core-crown reconstructions: an up to 17-year follow-up of a controlled clinical trial.

PURPOSE: The aim of this long-term follow-up study was to collect up to 17 years of survival data of endodontically treated single teeth with or without a prefabricated metal post. MATERIALS AND METHODS: Single teeth were provided with direct composite resin core-crown reconstructions with or without posts by 15 operators. Restorations consisted of either a prefabricated metal post and a composite core-crown reconstruction or a post-free direct composite reconstruction. Allocation of either restoration was performed by balanced drawing. These restorations were not covered by an artificial crown. The study sample consisted of 87 patients who received 98 core-crown reconstructions. The performance of the restorations was evaluated based on data collected from the files of the clinicians currently monitoring the oral health of the patients. The survival probability was analyzed at different levels: on the restoration level and on the level of the tooth carrying the restoration. Kaplan-Meier analysis was used to compare survival probabilities. RESULTS: Post placement showed no influence on the survival probability at either level (P > .05). The estimated overall survival rate at 17 years was 53% +/- 14% at the restoration level and 79% +/- 11% at the tooth level. CONCLUSION: The results of this long-term follow-up study showed no difference in survival probabilities between different direct composite resin core-crown reconstructions of endodontically treated single teeth (with or without a post).

Esthetic perception of missing teeth among a group of Tanzanian adults.

PURPOSE: To assess esthetic perceptions among Tanzanian adults regarding missing teeth using a cross-sectional clinical study of a convenience sample of 5,532 subjects in the Northern coastal zone of Tanzania. MATERIALS AND METHODS: The dental status of urban and rural Tanzanian adults (5,532 subjects, ages between 20 and 80 years) was recorded. A structured interview was used to assess esthetic perception (yes/no complaint) considering the location and number of missing teeth. Logistic regression analysis was applied to determine the effects of the variables age (2 groups: < or = 45 years vs > 45 years), gender, socioeconomic status (high/middle vs low), and residence (urban vs rural) on the number of complaints. RESULTS: Of the subjects with 1 or more missing maxillary anterior teeth, 54% reported a complaint. Dissatisfaction was reported by significantly more subjects < or = 45 years of age and subjects with high/middle socioeconomic status. Gender and residence had no significant influence. Of the subjects with missing maxillary premolar(s) (no missing anterior teeth), 25% reported esthetic complaints (missing first premolar: 24%; missing second premolar: 11%; missing first and second premolar on the same side: 44%). Dissatisfaction was significantly greater in women, subjects < or = 45 years of age, and subjects with high/middle socioeconomic status. Residence had no significant influence. Fewer than 1% of the subjects were dissatisfied with missing maxillary molars. CONCLUSION: Among this group of Tanzanian adults, absence of teeth played a considerable role in the esthetic appreciation of their dentition. Complaints were associated with both number and location of missing teeth.