Clinical Oral Investigations Research Articles

Top 100 Most Cited Articles on the use of Ozone in Dentistry: Bibliometric Analysis

Introduction: c density (number of citations per year), first author's country, year of publication, study design and subject. VOSviewer software was used to create graphical bibliometric maps. Results: The total number of citations papers which from 13 to 180, and only eight were cited more than 100 times. Papers were published from 1997 to 2022, mainly in dentistry journals. The studies originated from 30 different countries and the most papers were from Germany (16%) and Turkey (15%). In total, 250 keywords were used and the most used were ozone 50 (20%), dentistry 8 (3,2%) and periodontitis 7 (2,8%). Conclusions: 1) Germany was the main country that contributed to field research on the use of ozone in dentistry 2) The University of Basel was the most productive university in the researched field; 3) Clinical Oral Investigations was the journal that led the ranking with the most articles published, 4) The keyword ozone was the most used in the articles; 5) Oral and maxillofacial surgery was the research area most addressed by the 100 most cited articles.

Letter to the Editor about the article published in Clinical Oral Investigations titled "The contralateral-based submental artery island flap: feasibility and oncological safety in oral cancer-related defect reconstruction" (Ma J, Zhai X, Huang M, Li P, Liang Y, Ouyang D, Su YX, Yang WF, Liao G, Zhang S. Clin Oral Investig, https://doi.org/10.1007/s00784-023-05103-1).

Letter to the Editor about the article published in Clinical Oral Investigations titled "The contralateral-based submental artery island flap: feasibility and oncological safety in oral cancer-related defect reconstruction" (Ma J, Zhai X, Huang M, Li P, Liang Y, Ouyang D, Su YX, Yang WF, Liao G, Zhang S. Clin Oral Investig, https://doi.org/10.1007/s00784-023-05103-1).

How do periodontal indices compare among non-smokers, tobacco and e-cigarette smokers?

Design Systematic review and network meta-analysis.Data sources Medline (PubMed), ISI Web of Science and Scopus. Additionally, the following journals were hand-searched between 2000 and December 2021: Journal of Periodontology, Journal of Clinical Periodontology, Clinical Oral Investigations, International Journal of Periodontics and Restorative Dentistry. Citations of included articles and relevant systematic reviews were also screened.Study selection Cross-sectional and observational studies were included which compared periodontal indices in non-smokers, tobacco and e-cigarette smokers. A minimum sample of 25 patients in each group was required, as was reporting of bleeding on probing (BOP), plaque indices (PI) and probing depth (PD) outcomes.Data extraction and synthesis Two independent authors examined titles, abstracts and full texts of relevant articles against the inclusion criteria, with any disagreements resolved by discussion, or a third reviewer. Data was collected using an Excel spreadsheet and risk of bias assessed via the NIH quality assessment tool for observational cohort and cross-sectional studies. Results were pooled and checked for suitability before network meta-analysis for each separate outcome.Results In total, 279 studies were screened from electronic and hand searching with 28 full text articles assessed for eligibility. Twenty-three were excluded at full text, with five included for quantitative synthesis and review. The included studies incorporated a total of 512 patients encompassing 170 non-smokers, 176 tobacco smokers (mean duration 10.7 years) and 166 e-cigarette smokers (mean duration 3.7 years). All studies were based in Saudi Arabia only and 99% of patients were male with mean ages 37.8 (non-smokers), 39.5 (tobacco) and 33.5 (e-cigarette). No studies adjusted for key confounding variables, which limited risk of bias to fair or good in all cases. Meta-analysis suggested PD and PI were significantly worse in tobacco smokers compared to both non-smokers and e-cigarette smokers. BOP was significantly reduced in both smoking groups versus non-smokers.Conclusions Notwithstanding the limitations of this review, there is some evidence that supports accepted understanding that tobacco smoking can compromise periodontal health. E-cigarette smoking in this cohort showed no significant difference to non-smokers in terms of probing depth or plaque index and may be a safer source of nicotine for patients in terms of periodontal health. Greater understanding may be drawn from analysis of randomised controlled trials in wider populations that account for important confounding variables.

Effectiveness of root canal filling materials and techniques for treatment of apical periodontitis: A systematic review.

Apical periodontitis (AP) is an inflammatory disease of the apical periodontium as sequelae of pulp death. It is managed by disinfection and filling of the root canal space. The aim of this systematic review was to investigate whether obturation techniques and materials used for root canal filling led to the management of AP. A systematic review protocol was written following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and registered on the international prospective register of systematic reviews (PROSPERO; CRD42021260275) including two populations, interventions, comparisons, outcomes and time (PICOT) for the research questions querying the effectiveness of obturation techniques (PICOT 1) and materials (PICOT 2) for the management of AP. Electronic searches were conducted on PubMed, ScienceDirect, Scopus and Embase search engines. Searches on International Endodontic Journal, Journal of Endodontics, Clinical Oral Investigations, Journal of Dental Research and Journal of Dentistry websites were also conducted, until May 2021. Both primary (tooth survival) and secondary outcomes were evaluated. The risk of bias was assessed by Cochrane RoB2 for the randomized and ROBINS-I for the nonrandomized trials. The search strategy identified 1652 studies, with 1600 excluded on the title and abstract screening, leaving 52 studies for full-text screening. In total, 10 studies met the inclusion criteria. The obturation technique and materials used did not affect the outcome of AP. Vertical compaction resulted in faster resolution of periapical lesions. The oral health-related quality of life of patients treated with lateral condensation exhibited poorer outcomes compared with single matched cone after 6months of recall. The inclusion and exclusion criteria used for this systematic review enabled the capture of all the literature available on the effect of obturation techniques and materials on the outcome of AP. The data were heterogenous, and a number of articles investigating obturation techniques had no information on the materials and techniques used as they looked at the quality of fill. Included studies did not find any difference between different procedures (PICOT 1) and materials (PICOT 2). The risk of bias was high, thus the findings should be interpreted with caution. PROSPERO registration number: CRD42021260275.

Associations between Bolton ratio and overjet deviations in a Finnish adult population

Objective To determine the anterior Bolton ratio for a Finnish adult population and to investigate its associations with overjet. Material and methods This study is part of the Northern Finland Birth Cohort 1966. Clinical oral investigations, including three-dimensional intraoral scanning and registration of occlusion, were performed in connection with the 46-year follow-up for 1,961 subjects. Subjects with normal occlusion (n = 149), extreme overjet ≥ 8 mm (n = 49), large overjet 6–7 mm (n = 86), and negative overjet (n = 16) and no orthodontic treatment history were selected for further analysis. The mesiodistal widths were measured from canine to canine to evaluate the anterior Bolton ratio. Results A mean anterior Bolton ratio of 78.6 (SD 3.1) was found for the normal occlusion group. Subjects with extreme overjet had smaller Bolton ratios compared to the normal occlusion group and the negative overjet group (p = .005, p = .019, respectively). Overjet deviations were associated with upper canine and incisor widths. Conclusions The mean anterior Bolton ratio in subjects with normal occlusion was larger compared to the original Bolton ratio. Tooth size discrepancy was associated with extreme and negative overjet at population level.

What's new for the clinician? - Excerpts from and summaries of recently published papers

1. Is there an association between stress and periodontitis? JM Coelho, SS Miranda, SS da Cruz, et al. Is there association between stress and periodontitis? Clinical Oral Investigations. 2020; 24: 2285-94.
 2. Is there an association between periodontitis and all-cause and cancer mortality? P Chung, T Chan. Association between periodontitis and all-cause and cancer mortality: retrospective elderly community cohort study. BMC Oral Health. 2020; 20: 168.

Insomnia and psychological reactions during the COVID-19 outbreak in China.

Citation:Li Y, Qin Q, Sun Q, Sanford LD, Vgontzas AN, Tang X. Insomnia and psychological reactions during the COVID-19 outbreak in China. J Clin Sleep Med. 2020;16(8):1417–1418.

Correction to: Influence of surface treatment on osseointegration of dental implants: histological, histomorphometric and radiological analysis in vivo.

Dear Professor Dr. Matthias Hannig. Editor-in-Chief Clinical Oral Investigations. Following the publication of our paper by Calvo Guirado et al, 2015 [1] in Clinical Oral Investigations, it came to light that a certain part of the text at the materials and methods and results sections were similar.

No clear evidence on the clinical performance of different removable prosthetic options in partially edentulous patients.

Data sourcesMedline/PubMed, Embase, BIOSIS/Ovid, SciSearch/DIMDI, Cochrane library, FIZ Technik Web and hand searches of the journals; Clinical Oral Investigations, International Journal of Prosthodontics, Journal of Prosthetic Dentistry, Deutsche Zahnärztliche Zeitschrift, Swiss Dental Journal, Journal of Dentistry and the Journal of Dental Research.Study selectionRandomised controlled trials, prospective and retrospective studies on survival rates of removable dental prostheses in the moderately reduced dentition with at least 15 participants having an observation period of at least two years, and a dropout rate of less than 25% were considered.Data extraction and synthesisTwo reviewers abstracted data. A qualitative summary of the included studies was carried out. Studies providing data that permitted a Kaplan-Meier analysis were included in meta-analysis.ResultsThe review included 19 studies, six of which were in multiple publications. Cast-metal framework dentures showed failure rates of 33% and 50% after five years. One study with a 25-year observation period reported failure rates of 50%. Proper pretreatment and a good recall scheme improve the results. Bilateral attachment prostheses showed failure rates of 11% and 30% after five years. Unilateral attachment prostheses showed failure rates of 75% after five years. Double-crown prostheses dentures show failure rates of 0% to 21.7% after three to six years.ConclusionsWithin the limitations of this study, it seems that removable partial dentures, (RPD), given suitable pretreatment and follow-up regimes, can provide a satisfactory treatment option. Based on only one paper, they revealed acceptable results even over a very long observation period (25 years).

Impact of the CONSORT Statement endorsement in the completeness of reporting of randomized clinical trials in restorative dentistry

ObjectivesThe aim of this study was to assess if journal endorsement of the CONSORT Statement is associated with improved completeness of reporting of randomized controlled trials (RCTs) in restorative dentistry. Materials and methodsRCTs in restorative dentistry published in two journals that have (Journal of Dentistry and Clinical Oral Investigations) and have not (Operative Dentistry and Journal of Prosthetic Dentistry) endorsed the CONSORT Statement were selected. We compared the completeness of reporting between comparison groups (endorsers versus non-endorsers, before versus after endorsement) using a risk ratio (RR) with a 99% confidence interval for each outcome of CONSORT 2010. Also, the risk of bias of each study was evaluated. ResultsThe electronic search retrieved a total of 3701 records. After the title and abstract evaluation, 169 full texts were screened and 79 RCTs identified. Considering CONSORT-endorsing journals before and after CONSORT endorsement, six items had effect estimates indicating a relatively higher proportion of completely reported RCTs published after CONSORT endorsement. Considering CONSORT-endorsing journals compared to non-endorsing journals, twelve items indicated a relatively higher proportion of completely reported RCTs published in CONSORT-endorsing journals. In both analyses the overall evidence did not present statistical significance. ConclusionAlthough CONSORT endorsement has been linked with some improvement in the completeness of RCTs reports in the biomedical literature, this was not reflected in the present analysis confined to restorative dentistry. More innovative and involved approaches to enhancing reported may therefore be required.Clinical significance: Inadequate reporting of randomized controlled trials can produce important consequences for all stakeholders including waste of resources and implication on healthcare decisions. A broad understandment of the use of reporting guidelines is necessary to lead to better results.

Frequency of Obstructive Sleep Apnea Syndrome in Dental Patients with Tooth Wear

To estimate the frequency of obstructive sleep apnea syndrome (OSAS) in dental patients with tooth wear, and to assess the role of dentists in the identification of patients at risk of OSAS. Dental patients with tooth wear and treated with occlusal splint were prospectively recruited to perform sleep study. The severity of tooth wear was established by the treating dentist before patient referral to sleep disorders unit. Sleep questionnaires, anthropometric measurements, and validated respiratory polygraphy were performed. All patients with dental wear were offered a sleepiness analysis. Of 31 recruited patients, 30 (77% males) participated in this study. Patients' mean age was 58.5 ± 10.7 years (range: 35-90 years) and the body mass index was 27.9 ± 3.4 kg/m(2). Tooth wear was mild in 13 patients, moderate in 8 and severe in 9. The mean apnea-hypopnea index (AHI) was 32.4 ± 24.9. AHI < 5 was reported in 2 patients, AHI of 5-29 in 17, and AHI ≥ 30 in 11. A statistically significant association was found between AHI severity and tooth wear severity (Spearman R = 0.505; p = 0.004). Tooth wear could be a tool to identify those patients at risk of having OSAS. This highlights the importance of dental professionals to identify and refer patients with OSAS.

A three-year clinical evaluation of a one-step self-etch and a two-step etch-and-rinse adhesive in non-carious cervical lesions

ObjectivesThe aim of the study was to assess a one-step self-etch adhesive (Futurabond M, 1-SE) and a two-step etch-and-rinse adhesive (Solobond M, 2-ER) used in combination with the nano-hybrid composite (Amaris) in a prospective clinical study on non-carious cervical lesions. Methods110 restorations were placed in 40 patients and graded over 36 months according to aesthetical, functional and biological criteria (Clinical Oral Investigations 2007;11:5). The four-step etch-and-rinse adhesive Syntac classic (4-ER) combined with the nano-hybrid composite Tetric EvoCeram was used as a control. Cumulative failure rates (CFR), retention rates and Kaplan–Meier survival curves were calculated for each observation period. ResultsAfter 3 years, the CFR of 33.3% in the 2-ER group was significantly higher compared to those of the 1-SE group (9.1%, p=0.019) and of the 4-ER group (8.3%, p=0.035). Additionally, retention rates in the 1-SE and the 4-ER groups were higher compared to 2-ER (p=0.012 each) after 36 months. Annual failure rates ranged between 2.8% for 4-ER, 3.0% for 1-SE and 11.1% for 2-ER. During the study, restorations in all groups showed progressive marginal deterioration within the limits of clinical acceptance. After 3 years, restorations in the 2-ER and the 4-ER group showed more small defects at dentin than at enamel margins. ConclusionsThe 1-SE group was clinically as successful as the 4-ER, with both performing better than the 2-ER group. Futurabond M/Amaris can be recommended for the restoration of sclerotic non-carious cervical lesions. Clinical significanceNumber protocol 192/2008.

Periodontitis and dental implant loss

Medline, the Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effect, Science Direct, and SCOPUS databases were searched. A manual search was performed of issues of the last 15 years of the Journal of Periodontology, International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Journal of Dentistry, Clinical Oral Investigations, Clinical Oral Implant Research and Clinical Implant Dentistry and Related Research. Prospective cohort studies that compared patients with periodontal disease (PD) to periodontally healthy patients and that reported data on implant loss, peri-implant bone changes or incidence of peri-implantitis were included. Case series, reviews, case reports and retrospective studies were not included. Study selection and risk of bias assessment using the Newcastle-Ottawa Scale was undertaken independently by two reviewers. Dichotomous data were expressed as risk ratios (RRs) and 95% confidence intervals (CIs). Continuous data were expressed as standardised mean differences (SMDs) and random-effects meta-analysis conducted. Fourteen studies were included with sample sizes ranging from 10-717. Meta-analysis (11 studies) showed a higher and significant risk for implant loss in patients affected by PD (RR: 1.89, 95% CI: 1.35-2.66, P = 0.0002) with no evidence of heterogeneity (v2 = 4.31, P = 0.93; I2 = 0%). Significant implant bone loss was present in patients with PD compared with periodontally healthy patients (SMD: 0.44, 95% CI: 0.19-0.69, P = 0.0006) (three studies), with no evidence of heterogeneity (v2 = 2.463, P = 0.27; I2 = 24%). Periodontally compromised patients also showed an increased risk of peri-implantitis compared with patients without PD (RR: 2.21, 95% CI: 1.42-3.43, P = 0.0004), with moderate but not significant heterogeneity (v2 = 7.35, P = 0.12; I2 = 46%). Meta-analysis (seven studies) found that patients with both aggressive and chronic periodontitis had an increased risk of implant loss. The risk was greater for patients with aggressive periodontitis (RR: 4.04, 95% CI: 1.81-8.98, P = 0.0006) compared with patients with chronic periodontitis (RR: 1.59, 95% CI: 1.10-2.32, P = 0.01).When stratifying only those patients with chronic periodontitis, those with severe periodontitis had increased risks of implant loss (RR: 1.89, 95% CI: 1.16-3.07, P = 0.01). Higher risks were also seen for patients with moderate (RR: 2.54, 95% CI: 0.65-9.93, P = 0.18) and severe periodontitis (RR: 3.12, 95% CI: 0.92-10.57, P = 0.07). Strong evidence suggests that periodontitis is a risk factor for implant loss; moderate evidence revealed that periodontitis is a risk factor for peri-implantitis and that patients with periodontitis have higher implant-bone loss.

Comment on “Development of digital shade guides for color assessment using a digital camera with ring flashes [Oi-Hong Tung et al., Clinical Oral Investigations (2011) 15:49–56

Comment on “Development of digital shade guides for color assessment using a digital camera with ring flashes [Oi-Hong Tung et al., Clinical Oral Investigations (2011) 15:49–56

Is It Time to Consider Photobiomodulation As a Drug Equivalent?

The question of whether photobiomodulation should be used as a drug equivalent arose in my mind after listening to presentations at the recent conference of the World Association for Laser Therapy (WALT)-2012 (Gold Cost City, Australia), and later at home when searching MEDLINE for the years 2009–2012. Photobiomodulation (earlier terms: low level laser therapy, LLLT, laser biostimulation) has been used in clinical practice for >40 years by now, and its action mechanisms on cellular and molecular levels have been studied for > 30 years. Enthusiastic medical specialists successfully used photobiomodulation in treating healing-resistant wounds and ulcers (e.g., chronic diabetic ulcers), in pain management, and in spinal cord and nervous system injuries when other methods had had limited success. However, photobiomodulation is still not a part of mainstream medicine. The goal of the present Editorial is to highlight some important recent developments in clinical applications and in studies of cellular and molecular mechanisms behind the clinical findings. One of the impressive and perspective challenges for photobiomodulation is its use in cases of Parkinson’s disease. Research in recent years evidenced that neuroprotective treatment with red and near infrared radiation (NIR) prevented mitochondrial dysfunction and dopamine loss in Parkinson’s disease patients. In another set of experiments, NIR normalized mitochondrial movement and axon transport, as well as stimulating respiration in cytoplasmic hybrid (‘‘cybrid’’) neurons. It is important to recall that reduced axonal transport contributes substantially to the degeneration of neuronal processes in Parkinson’s disease. Another development in recent years is the successful stimulation of stem cells with red and NIR radiation. One example is the treatment of myocardial infarction. The heart has been considered a post-mitotic organ lacking the capacity for self-renewal after injury. Surprisingly enough, human cardiac stem cells, in combination with bone marrow mesenchymal stem cells, were found to reduce infarct size and restore cardiac functions after myocardial infarction. This positive effect can even be increased by irradiation of stem cells. Mesenchymal stem cells were derived from bone marrow and adipose tissue, and stimulated by irradiation at k = 810 nm. Implantation of irradiated cells into the infarcted rat heart resulted in an *50% decrease in cardiac infarct size. An increase in proliferation rates and membrane potential was established after 532 nm irradiation of adipose tissue-derived stem cells. A recent review summarized data about enhancement of the proliferation of various cultured cell lines, including stem cells, as well as cell lines used for the production of viral vaccines and hybrid cell lines. The review underlined that photobiomodulation improves the proliferation of cells without causing any cytotoxic effects. One has to emphasize that laser therapy shares none of the risks associated with stem cell therapy, requires no anesthesia, and is painless. The optimal light parameters in this review were found to be as follows: doses were 0.5–4.0 J/ cm and wavelengths ranged from 600 to 700 nm. It is important to recall that, in this particular wavelength range, two peaks in absorption and action spectra connected with activation of cytochrome c oxidase (the primary photoacceptor for photobiomodulation effects) are situated. The peak at 620 nm belongs to reduced CuA, and that at 680 nm, to oxidized CuB atoms in cytochrome c oxidase molecule. The treatment of vitiligo (a depigmentary disorder) remains a challenge for clinical dermatologists. He-Ne laser irradiation was found to stimulate melanocyte proliferation. The expression of phosphorylated cyclic-adenosine monophosphate (AMP) response element-binding protein, an important regulator of melanocyte growth, was upregulated by He-Ne laser treatment. He-Ne laser irradiation imparted a growth stimulatory effect on functional melanocytes via mitochondria-related pathways. Irradiation with red light caused gene and noncoding RNA regulation for photoacceptor protection in the retina. This finding may open a new challenge for photobiomodulation. One of the major dose-limiting effects of chemotherapy drugs is oral mucositis of treated patients. Oral mucositis can affect up to 100% of patients undergoing high-dose chemotherapy and hematopoietic stem cell transplantation. Photobiomodulation can improve tissue repair and immune response in these patients. Photobiomodulation has been shown to improve functional outcome after surgical intervention to repair injured nerves. LED irradiation at 810 nm accelerated functional recovery and improved the quality of nerve regeneration after autograft repair of severely injured peripheral nerves. Forehead treatments with NIR reversed major depression and anxiety. Transcranial NIR laser therapy was investigated

Accuracy of peri-implant bone thickness and validity of assessing bone augmentation material using cone beam computed tomography—is this correct?

We were interested to read the paper by Wang D and colleagues published in the Oct 2012 issue of Clinical Oral Investigations. The authors assessed the accuracy of measuring bone thickness surrounding dental implants and the reliability of assessing existence and completion of osseous integration of augmentation material using a cone beam computed tomography (CBCT) system [1]. They reported that the mean and the standard deviation of the differences between radiological and histological measurements of periimplant bone thickness were −0.22 and 0.77 mm, respectively. Sensitivity and specificity were 0.77 and 0.60 for existence of bone augmentation materials (BAM), 0.59 and 0.74 for completed integration and 0.39 and 0.71 for full covering of the implant surface [1]. As the authors point out in their conclusion, the PaX Duo3D® CBCT system allows measurements of periimplant bone thickness at an accuracy of half a millimeter and—within limits—the assessing of the existence and integration of BAM. The common practice is to employ relevant well-known statistical tests for assessing accuracy and reliability of a test, and it is unclear why the authors did consider employing only sensitivity and specificity. The authors did not apply positive and negative predictive value likelihood ratio positive and negative (LR+ and LR−) as well as odds ratio (true/false), which are among the tests to evaluate the validity (accuracy) of a single test compared to a gold standard [2–4]. Applying these tests would have added value to the study. They also did not apply any of the well-known statistical tests for reliability analysis such as intraclass correlation coefficient and weighted kappa for quantitative and qualitative variables, respectively [2–5]. Reliability and validity are two completely different methodological issues in researches. As a take-home message, for reliability and validity analysis, appropriate tests should be applied; otherwise, we will face misinterpretation of the results leading to mismanagement of our patients.

Reliability of shade selection using an intraoral spectrophotometer: common mistakes in reliability analysis

We were interested to read the paper by Witkowski S and colleagues published in the June 2012 issue of Clinical Oral Investigations. The authors’ aim was to evaluate the accuracy and reproducibility of human tooth shade selection using a digital spectrophotometer. They report the mean colour difference from the mean metric for measurement precision (reliability)! Also, least square test was used to assess interand intra-observer reliability [1]. Why did the authors not use well-known statistical tests for reliability analysis such as intra-class correlation coefficient for quantitative variables, weighted kappa for qualitative ones [2–5] or other methods such as coefficient of variance for repeatability [2–5], considering that the mean of the variables and using paired t test, least square test or correlation coefficient (r) are among the common mistakes in reliability analysis [2–5]? Regarding reliability or agreement, it is good to know that not only avoiding common mistakes in reliability analysis but also taking into account clinical importance instead of statistical significance is a crucial issue in clinical reliability researches [2–5]. The authors computed the confidence interval (CI) value 5.23 (4.66–5.86) to represent the accuracy (validity) of the measurements! As the authors point out in their conclusion, the accuracy and reproducibility of dental shade selection using the tested spectrophotometer with respect to examiner and illumination conditions reflected the reliability of this device [1]. A narrow CI has nothing to do with accuracy. We have seven well-known statistical tests for validity (accuracy) analysis, as follows: sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratio positive (LR+), likelihood ratio negative (LR−) and finally odds ratio [2–5]. Briefly, accuracy and precision (validity and reliability) are two completely different methodological issues in clinical researches, having their own statistical tests, and should not be confused with each other; otherwise, misdiagnosis, mistreatment and mismanagement of the patients will be the result of such researches.

Are lasers as effective as scaling for chronic periodontitis?

Medline, Cochrane Database of Systematic Reviews (CDSR), Database of Abstracts of Reviews of Effects (DARE), CINAHL, Science Direct, ISI Web of Science, and SCOPUS. The following journals were hand searched: Journal of Periodontology, International Journal of Periodontics and Restorative Dentistry, Journal of Clinical Periodontology, Journal of Dental Research, Journal of Periodontal Research, Periodontology 2000, Journal of Dentistry, Journal of American Dental Associations, Journal of Clinical Dentistry, Lasers in Medical Science, Lasers in Surgery and Medicine, Clinical Oral Investigations, and Photomedicine and Laser Surgery as well as the reference lists of included articles. Randomised controlled clinical trials (RCTs) comparing Er:YAG laser with manual or ultrasonic SRP alone were included. No language restrictions were applied. Data were collected by two independent reviewers with only numeric data being extracted. Data were combined for meta-analysis with the effect size being estimated and reported as the mean difference (MD) for continuous variables using a random effects model. Heterogeneity was assessed using the ÷2-based Q-statistic method and I(2) measurement. Five trials met the inclusion criteria. Five trials (85 patients and 3,564 sites) were entered in the meta-analysis to investigate clinical attachment level (CAL) gain, pocket depth (PD) reduction and gingival recession (GR). All studies reported significant intragroup improvement in clinical and microbiological parameters in patients treated with the Er:YAG laser. However, three studies did not report a significant difference between Er:YAG laser and SRP groups in CAL gain, PD reduction or GR changes. The meta-analysis revealed no significant differences for any investigated parameters at six and 12 months. Significant heterogeneity, a high risk of bias in three of the five included studies, and methodological shortcomings indicate that the results should be considered with caution. Future long-term, well-designed RCTs are needed to assess the scientific evidence of Er:YAG laser efficacy as an alternative treatment strategy to SRP.

Randomized Trials Published in the Journal of Dental Research are Cited More Often Compared with Those in Other Top-Tier Non–Specialty-Specific Dental Journals

Randomized controlled trials (RCTs) are viewed as the gold standard for clinical research. Oftentimes the citation counts serve as an important measure for assessing the significance of an RCT to promote the dissemination of science. This study attempts to identify the factors associated with the number of times RCTs are cited within the first 24 months since publication. RCTs published between January 1, 2002, and November 30, 2006, in 4 journals (Journal of Dental Research, European Journal of Oral Sciences, Journal of Dentistry, and Clinical Oral Investigations) were selected for analysis. Citation counts of RCTs in the first 24 months since publication was the outcome variable. The independent variables included journal of publication, geographic region of origin of study, number of authors, financial support, number of references, presentation of a statistically significant result, and if the study was conducted on animals. Bivariate associations between the outcome and independent variables were examined by Kruskal-Wallis test, Mann-Whitney U test, and Spearman rank correlations where appropriate. A multivariable negative binomial regression model was also built to examine the association. A total of 163 RCTs were selected for analysis. The mean citation count for the first 24 months count was 2.61. Close to 20% of RCTs were not cited even once in this observation period. RCTs published in the highest impact factor journal (Journal of Dental Research) tended to be cited most often (P < .05). Based on our initial analysis of 4 journals, publishing randomized trials in high-impact journals will likely provide better dissemination of research findings.

Recommendations for conducting controlled clinical studies of dental restorative materials

About 35 years ago, Ryge provided a practical approach to evaluation of clinical performance of restorative materials. This systematic approach was soon universally accepted. While that methodology has served us well, a large number of scientific methodologies and more detailed questions have arisen that require more rigor. Current restorative materials have vastly improved clinical performance and any changes over time are not easily detected by the limited sensitivity of the Ryge criteria in short term clinical investigations. However, the clinical evaluation of restorations not only involves the restorative material per se but also different operative techniques. For instance, a composite resin may show good longevity data when applied in conventional cavities but not in modified operative approaches. Insensitivity, combined with the continually evolving and non-standard investigator modifications of the categories, scales, and reporting methods, has created a body of literature that is extremely difficult to meaningfully interpret. In many cases, the insensitivity of the original Ryge methods is misinterpreted as good clinical performance. While there are many good features of the original system, it is now time to move to a more contemporary one. The current review approaches this challenge in two ways: (1) a proposal for a modern clinical testing protocol for controlled clinical trials, and (2) an in-depth discussion of relevant clinical evaluation parameters, providing 84 references that are primarily related to issues or problems for clinical research trials. Together, these two parts offer a standard for the clinical testing of restorative materials/procedures and provide significant guidance for research teams in the design and conduct of contemporary clinical trials. Part 1 of the review considers the recruitment of subjects, restorations per subject, clinical events, validity versus bias, legal and regulatory aspects, rationales for clinical trial designs, guidelines for design, randomization, number of subjects, characteristics of participants, clinical assessment, standards and calibration, categories for assessment, criteria for evaluation, and supplemental documentation. Part 2 of the review considers categories of assessment for esthetic evaluation, functional assessment, biological responses to restorative materials, and statistical analysis of results. The overall review represents a considerable effort to include a range of clinical research interests over the past years. As part of the recognition of the importance of these suggestions, the review is being published simultaneously in identical form in both the “Journal of Adhesive Dentistry” and the “Clinical Oral Investigations.” Additionally an extended abstract will be published in the “International Dental Journal” giving a link to the web full version. This should help to introduce these considerations more quickly to the scientific community.