Kreulen, Cees

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. Keywords: CAD-CAM, case report, digital workflow, indirect composite materials, minimally invasive, oral rehabilitation, restorative dentistry, 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. Keywords: tooth wear, composite resins, occlusal vertical dimension, dental restoration, oral health-related quality of life, CAD/CAM, oral rehabilitation, restorative materials, minimally invasive

Purpose: The aim of this study was to examine the effect of remaining buccal cavity wall, remaining cervical tissue, and post on the fracture strength of endodontically treated restored premolars. Materials and Methods: Teeth were randomly allocated to 10 experimental groups (n = 10) according to cavity design and presence or absence of post or to a control group. After thermal and mechanical aging, ramped loading until fracture was performed. Results: A high cervical outline (417 N) and the presence of a post (189 N) increased fracture strength, but both factors together had an antagonistic effect of −218 N, resulting in a higher strength of not 606 N (417 + 189) but 388 N. The risk of catastrophic failure increased (OR = 3.17) when a post was present.

In dieser Pilotstudie sollte überprüft werden, ob Okklusionskontakte während lateraler Exkursionsbewegungen von der jeweiligen Körperposition beeinflusst werden. Mithilfe von Shimstockfolie wurden die Okklusionskontakte bei lateralen Exkursionsbewegungen bei 30 Zahnmedizinstudenten und 22 Fakultätsmitgliedern überprüft, während sich diese in einem Behandlungsstuhl befanden. Dabei wurden Anzahl und Position der dynamischen Okklusionskontakte (initial und auf halbem Weg) registriert, während sich die Patienten im Behandlungsstuhl in aufrechter, geneigter oder liegender Position befanden. Keywords: Okklusion, Okklusionskontakte, laterale Exkursionsbewegung, Körperposition

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. Keywords: tooth wear, composite, treatment, occlusal vertical dimension

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.

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.

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).

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: £ 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 £ 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 £ 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.

Purpose: This study aimed to assess the efficacy and short-term effectiveness of the morphology and function of direct and indirect cusp-replacing resin composite restorations. Materials and Methods: In 94 patients, 106 cusp-replacing restorations for maxillary premolars were fabricated to restore Class II caries lesions with 1 cusp missing. Fifty-four direct (Clearfil AP-X) and 52 indirect (Estenia) resin composite restorations were placed following a strict protocol. The treatment technique and operator were assigned randomly. Treatment time was recorded for all restorations. One-month postoperative evaluation included assessment of postoperative sensitivity and presence of occlusal and proximal contacts. Results: Treatment time for the indirect technique (68 ± 17 min) was longer than for the direct technique (45 ± 13 min). Regression analysis revealed that the restorative method, operator, and location of the preparation outline had a statistically significant effect on the total treatment time. Occlusal contacts were observed in 94% of the direct restorations and in 98% of the indirect restorations (chi-square, P > .05). Mesial proximal contacts were present in 98% of the direct and in 97% of the indirect restorations (chi-square, P > .05). Distal contacts were present in 100% of the restorations for both techniques. Postoperative sensitivity within 1 week posttreatment was reported for 11% of the direct restorations and for 13% of the indirect restorations, but decreased to 4% and 6%, respectively, after 1 month (chi-square, P > .05). Conclusion: The results of this study suggest that in the short term, both direct and indirect adhesive techniques are adequate to restore the morphology and function of premolars presenting with Class II caries lesions and a missing cusp.