N.H.J. Creugers

Implant Surface Roughness and Bone Healing: a Systematic Review

A systematic review was performed on studies investigating the effects of implant surface roughness on bone response and implant fixation. We searched the literature using MEDLINE from 1953 to 2003. Inclusion criteria were: (1) abstracts of animal studies investigating implant surface roughness and bone healing; (2) observations of three-month bone healing, surface topography measurements, and biomechanical tests; (3) provision of data on surface roughness, bone-to-implant contact, and biomechanical test values. The literature search revealed 5966 abstracts. There were 470, 23, and 14 articles included in the first, second, and third selection steps, respectively. Almost all papers showed an enhanced bone-to-implant contact with increasing surface roughness. Six comparisons were significantly positive for the relationship of bone-to-implant contact and surface roughness. Also, a significant relation was found between push-out strength and surface roughness. Unfortunately, the eventually selected studies were too heterogeneous for inference of data. Nevertheless, the statistical analysis on the available data provided supportive evidence for a positive relationship between bone-to-implant contact and surface roughness.

Tooth loss and oral health-related quality of life: a systematic review and meta-analysis

BackgroundIt is increasingly recognized that the impact of disease on quality of life should be taken into account when assessing health status. It is likely that tooth loss, in most cases being a consequence of oral diseases, affects Oral Health-Related Quality of Life (OHRQoL). The aim of the present study is to systematically review the literature and to analyse the relationship between the number and location of missing teeth and oral health-related quality of life (OHRQoL). It was hypothesized that tooth loss is associated with an impairment of OHRQoL. Secondly, it was hypothesized that location and distribution of remaining teeth play an important role in this.MethodsRelevant databases were searched for papers in English, published from 1990 to July 2009 following a broad search strategy. Relevant papers were selected by two independent readers using predefined exclusion criteria, firstly on the basis of abstracts, secondly by assessing full-text papers. Selected studies were grouped on the basis of OHRQoL instruments used and assessed for feasibility for quantitative synthesis. Comparable outcomes were subjected to meta-analysis; remaining outcomes were subjected to a qualitative synthesis only.ResultsFrom a total of 924 references, 35 were eligible for synthesis (inter-reader agreement abstracts κ = 0.84 ± 0.03; full-texts: κ = 0.68 ± 0.06). Meta-analysis was feasible for 10 studies reporting on 13 different samples, resulting in 6 separate analyses. All studies showed that tooth loss is associated with unfavourable OHRQoL scores, independent of study location and OHRQoL instrument used. Qualitative synthesis showed that all 9 studies investigating a possible relationship between number of occluding pairs of teeth present and OHRQoL reported significant positive correlations. Five studies presented separate data regarding OHRQoL and location of tooth loss (anterior tooth loss vs. posterior tooth loss). Four of these reported highest impact for anterior tooth loss; one study indicated a similar impact for both locations of tooth loss.ConclusionsThis study provides fairly strong evidence that tooth loss is associated with impairment of OHRQoL and location and distribution of tooth loss affect the severity of the impairment. This association seems to be independent from the OHRQoL instrument used and context of the included samples.

The shortened dental arch concept and its implications for oral health care.

The minimum number of teeth needed to satisfy functional demands has been the subject of several studies. However, since functional demands--and consequently the number of teeth needed--can vary from individual to individual, this minimum number cannot be defined exactly. In general, occlusion of a complete dental arch is preferable. However, this goal might be neither attainable, for general, dental or financial reasons, nor necessary. Many studies demonstrate that shortened dental arches comprising the anterior and premolar regions can meet the requirements of a functional dentition. Consequently, when priorities have to be set, restorative therapy should be aimed at preserving the most strategic parts of the dental arch: the anterior and premolar regions. This also implies that in cases of a shortened dental arch, the prompt replacement of absent posterior molars by free-end removable partial dentures leads to overtreatment and discomfort. The shortened dental arch concept is based on circumstantial evidence: it does not contradict current theories of occlusion and fits well with a problem-solving approach. The concept offers some important advantages and may be considered a strategy to reduce the need for complex restorative treatment in the posterior regions of the mouth.

Systematic review of the prevalence of tooth wear in children and adolescents.

Data on the prevalence of tooth wear among children and adolescents are inconsistent. Given the impact of extensive tooth wear for over a lifetime, evidence on the extent is required. The aim was to systematically review the literature on the prevalence of tooth wear in children and adolescents. A PubMed literature search (1980–2008) used the keywords ‘tooth’ AND ‘wear’; ‘dental’ AND ‘attrition’ AND ‘prevalence’; ‘dental’ AND ‘wear’ AND ‘prevalence’; ‘erosion AND prevalence’ AND ‘abrasion AND prevalence’. Following exclusion criteria, 29 papers were reviewed using established review methods. There was a total of 45,186 subjects (smallest study 80 and largest study 17,047 subjects) examined from thirteen multiple random clusters, eight multiple convenience clusters and eight convenience clusters. Nine different tooth wear indices were used, but the common denominator among studies was dentin exposure as an indicator of severe wear. Forest plots indicated substantial heterogeneity of the included studies. Prevalence of wear involving dentin ranged from 0 to 82% for deciduous teeth in children up to 7 years; regression analysis showed age and wear to be significantly related. Most of the studies in the permanent dentition showed low dentin exposure, a few reported high prevalence (range 0–54%); age and wear were not related (regression analysis). The results of this systematic review indicate that the prevalence of tooth wear leading to dentin exposure in deciduous teeth increases with age. Increase in wear of permanent teeth with age in adolescents up to 18 years old was not substantiated.

A Seven-and-a-half-year Survival Study of Resin-bonded Bridges

A clinical trial, concerning 203 resin-bonded bridges (RBBs), was performed for investigation of the influence of retainer-type and cementation materials on the survival of these restorations. The survival rates after a 7.5-year follow-up were 75% for anterior RBBs and 44% for posterior bridges. Etched metal RBBs (E-bridges) were significantly more retentive than perforated RBBs (P-bridges); the survival rates were 78% and 63%, respectively. With respect to the cementation materials, Clearfil F, in combination with E-bridges, had the best overall survival (89%, anterior and posterior). Maxillary anterior RBBs were more susceptible to failure than mandibular anterior RBBs.

An analysis of durability data on post and core restorations

An attempt was made to review the dental literature since 1970, presenting clinical data of posts and core restorations, by the use of a meta-analytic procedure. Fourteen publications were found that contained durability data on post and core systems. According to the exclusion criteria 11 studies were excluded for further analysis of the data. The survivals of these studies varied from 98.6% survival after a follow-up period of more than 10 years (F.S. Weine et al. 1991, J. Endodont. 17, 293-297) to 77.6% survival after a mean follow-up period of 5.2 years (D.H. Roberts, 1970, Br. Dent. J. 128, 117-124). The data of the three selected studies were reconstructed according to the method of Kaplan-Meier but could not be combined for an overall survival assessment because the study characteristics were too heterogeneous. Therefore the survivals were presented separately. The reconstructed survivals of the studies after 6 years were 81% survival (standard error 6%) for resin composite build-ups in combination with screw posts and 91% survival for two studies including cast posts and cores (standard errors respectively 3% and 2%). Although it was not meaningful to combine the data for an overall survival, the meta-analytic method of this study revealed homogenic survival data and as such the followed procedure is considered to be an appropriate method to obtain insights in clinical durability data.

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.

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.

Four bonding systems for resin-retained cast metal prostheses

Abstract The aim of this study was to test and evaluate 4 resin-metal bonding systems for tensile bond strength. The resin-metal bonds were established between pairs of similar, and simultaneously treated Co−Cr and Ni−Cr cylinders. Before testing, the bonds were stored for 1 h dry at room temperature or in water 37°C for 1 week. The systems tested were: (1) silicoating (Micropont), (2) sandblasting (Panavia Ex), (3) electroplating (Panavia Ex) and (4) etching (Clearfil F). Highest bond strength values were found for silicoated and sandblasted Co−Cr samples whereas lowest bond strength values were found for etched Ni−Cr samples.

Long-term survival data from a clinical trial on resin-bonded bridges

OBJECTIVES A clinical trial, involving 203 resin-bonded bridges (RBBs) was undertaken to investigate the influence of retainer-type and luting material on the survival of these restorations. METHODS For this evaluation, 157 patients were available (14% of the original sample was lost to follow-up or excluded from the study following the stopping criteria). Fifty per cent of the patients were questioned concerning the fate of the RBBs and 59% of questioned patients were examined clinically. The patients that were seen for examination were representatives of the experimental groups. The findings from the clinical examination were compared with the data obtained from the questionnaire. Missing data were censored at the date of the last available information. Kaplan-Meier estimates were calculated to assess the survivals at the endpoints and compared using Coxs proportional hazards procedure. RESULTS A significant difference was found between perforated (P-type) and etched (E-type) RBBs (P = 0.05) for original bonded restorations but not when rebonded RBBs were taken into account. The results of the survival analysis were: anterior P-type, 49 +/- 7% after 10.5 years: anterior E-type, 57 +/- 7% after 10.5 years; posterior P-type, 18 +/- 11% after 6.8 years; posterior E-type, 37 +/- 13% after 10.2 years. Survivals of RBBs that were rebonded once during the evaluation period were 62 +/- 9% (11.0 years) for anterior RBBs and 51 +/- 11% (10.2 years) for posterior RBBs. CONCLUSIONS The factor location (anterior versus posterior) was as in previous analyses, highly significant. Differences in survival between cementation materials were not significant.