AIM: This systematic review evaluated criteria used to determine the survival and success of the rehabilitation of the completely edentulous mandible with template guided implant placement and restoration via fixed prostheses. After reviewing these variables the intent was to propose a new set of criteria that addresses current expectations of success and facilitates a better comparison of future materials, rehabilitation protocols, and comparative studies MATERIALS AND METHODS: Using a systematic search process guided by PICOS and PRISMA, two electronic databases, PubMed and Science Direct, were searched for clinical studies to evaluate the definition of success regarding the restoration of a complete mandibular implant supported fixed dental prosthesis. The analysis was confined to prospective studies with a minimum follow-up of 3 years and a minimum of 10 patients per study published prior to June 24th, 2021. RESULTS: The preliminary search defined with PICOS-derived MeSH terms resulted in 781 publications. The titles and abstracts were evaluated using both the PRISMA checklist and defined inclusion and exclusion criteria, resulting in inclusion of 10 articles. Analysis of the selected articles resulted in the following:1. It is difficult to derive a definitive conclusion since there was little uniformity in study design or the individual investigator’s criteria used to evaluate the data. 2. Implant and fixed prosthesis survival rates can be high in the short-term when at least 2 implants are placed. 3. The survival and success of implants and implant supported fixed prostheses was not dependent upon the type of surgical guide used. 4. The success and survival of implants and implant supported fixed prostheses was not affected by immediate loading of the prostheses. 5. Immediate loading of the prostheses did not affect the success and survival of implant and implant supported fixed prostheses. CONCLUSION: New criteria that are widely accepted, reproducible, and easy to implement should be established to address current expectations of success and facilitate a better comparison of future materials, rehabilitation protocols, and comparative studies (Table 11).

The rate of tooth decay has declined since the start of fluoridation in the United States. Fluoridation was initiated when evidence of fluoride’s ability to make teeth stronger and more resistant to acid was reported. Despite the benefits of fluoride, many researchers using inbred mice have shown that excessive amounts of this trace element leads to fluorosis and eventually skeletal fluorosis, which can lead to osteoporosis. Interestingly, the downward trend in the rate of decline in tooth decay is also observed in various countries that do not participate in fluoridation programs, including both developed and developing countries. This decline is likely due to the high fluoride concentration within their natural waters in combination with improved oral hygiene care. Since excessive amounts of fluoride have been known to cause discoloring of teeth, decalcification of enamel, lower intelligence quotient, arthritis, osteoporosis, etc., it is also surprising that the United States consumes more fluoride than the rest of the world combined. Although fluoridation of water remains the most cost effective treatment for tooth decay in the United States its use has decreased, suggesting it may no longer be needed. To test the need of fluoridation a comparison of developed countries, which participate in fluoridation, including the United States and the United Kingdom was made with developing counties that do not participate in fluoridation programs, such as Sudan, China, and India. Observations made from several studies and discussed here demonstrate that tooth decay is positively influenced by fluoridation but can also contribute negatively to fluorosis. Even though medical treatment is more advanced in developed countries than in developing countries, tooth decay still is a major health concern in both. Factors such as socioeconomic status and lifestyle behaviors are influential and need to be considered when determining the best approach to decrease tooth decay in communities.

Introduction:One of the most important steps in endodontic treatment includes the shaping and instrumentation of the root canal system. If not done properly, it may lead to errors including canal transportations and uncentered preparations. Over the last decades, nickel-titanium (NiTi) rotary instruments have enhanced the quality of root canal shaping for clinicians. Currently, two common NiTi rotary instruments, WaveOne Gold and ProTaper Gold, function by two different forms of kinematics: a reciprocating and rotating movement respectively. Currently, preclinical curricula in dental schools do not have a standardized rotary file in which dental students are introduced into endodontics with. This study looks at the use of these two rotary systems by novice sophomore dental students on the quality of their root canal preparations. Purpose: This study aims to examine the influence of kinematics of nickel-titanium instruments (reciprocation vs rotation) on the shaping ability, canal transportation and centering ratio, of novice pre-doctoral sophomore dental students and their preference after its use. Materials and Methods: Forty two identical pre-accessed mandibular left first molar 3-dimensional printed replicas’ mesial canals (TrueTeeth; PlanBDental) were instrumented by 21 novice pre-doctoral sophomore dental students. Each canal was previously hand instrumented to a size #15 K file by a single provider. The students were recruited using a random number generator. The teeth were divided up into 2 groups for each rotary file system being used: ProTaper Gold (PTG) (n=21) and WaveOne Gold (WOG) (n=21). Each student instrumented both the mesiobuccal (MB) and mesiolingual canals (ML) using each system. The total instrumentation time was recorded. Micro-computed tomography was used to scan the teeth before and after instrumentation. Centering ratios and canal transportation were calculated at the apical, middle and coronal levels. A questionnaire was completed after instrumentation regarding students’ perception with a 5-point Likert scale: ease of use, flexibility, cutting efficiency, screwing effect and overall impression. Conclusion: Compared to a rotation NiTi file system, reciprocation NiTi file system was preferred by novice sophomore dental students, and it also showed less canal transportation and better centering ability with shorter instrumentation times. Future studies are still needed in order to assess if there are further advantages to training novice dental students with reciprocating rotary systems when learning endodontics, but this study can serve as a framework to answer the question. / Oral Biology

Objective: Failed root canals have been associated with a variety of microorganisms, such as Entercoccus faecalis (E. faecalis) and Candida albicans (C. albicans). The goal of the present study is to better understand the interactions between E. faecalis and C. albicans. Specifically, the cellular morphology of these interactions and the effect on cell aggregation and biofilm formation. Since much of C. albicans’ adhesion mechanisms are regulated by high iron levels, this study also seeks to analyze the role of iron in the interactions between C. albicans and E. faecalis. Methods: Individual cultures of E. faecalis and C. albicans as well as co-cultures of both were prepared in 1:1 mixture of brain heart infusion and RPMI media in high and low iron conditions. Growth curves were created for each culture. Biofilm formation of cultures was measured through crystal violet analysis. Sedimentation assay at OD600 was used to measure cellular aggregation. Cells were observed under microscope to view cellular interactions. Results: Regardless of iron levels, growth of C. albicans was reduced when grown in co-culture with E. faecalis (p < 0.0001). Biofilm formation was reduced in cocultures of E. faecalis and C. albicans under high iron conditions, OD600=2.13, compared low iron conditions, OD600=3.60 (p < 0.0001). Microscopy showed a lack of aggregation of E. faecalis along C. albicans hyphae. Conclusion: E. faecalis and C. albicans show an antagonistic relationship that restricts normal biofilm formation and growth in high iron conditions. / Oral Biology

Objectives: Orthodontic patients treated with traditional metal braces exhibit an increased risk of forming enamel decalcifications known as white spot lesions (WSLs) on facial surfaces of teeth. This is due to the increased surface area around which plaque can adhere with brackets bonded. It is not currently known whether malocclusion complexity contributes to WSL formation. The Salzmann Index (SI) is a set of criteria that quantifies malocclusion complexity. In Pennsylvania, it is used in patients under 21 years to determine eligibility for orthodontic Medicaid insurance coverage. This study aims to determine if SI score impacts the incidence of WSLs among patients treated with traditional braces. Methods: 200 subjects between 10-18 years who completed >12 months of orthodontic treatment with metal braces were compared for SI scores and oral hygiene (OH). Pre-treatment OH was obtained from clinical exam forms. Pre- and post- intraoral photos of facial surfaces of upper and lower anterior dentition segments were analyzed. Presence and severity of WSLs, and mid- and post-treatment OH were determined by amount of tooth surface with lesion involvement, and localized vs. generalized gingival swelling, redness, and plaque, respectively. Hygiene and WSL’s were scored on 3-point scales. Statistical analysis was performed for each variable using R2 values. Results: There was a significant difference in WSLs pre- versus post-treatment (p<0.001). Higher SI score, average overall OH, and pre-treatment WSLs were all significant predictors of post-treatment WSLs (p=.007, p=.014, p=.000, respectively). Salzmann Index score and OH showed moderate level correlation to WSLs (R2=0.22 for both), while pre-treatment WSLs showed low level correlation (R2=0.07). Duration of treatment was not a significant predictor of post-treatment WSLs (p=.654). Conclusion: Findings suggest that patients with higher SI scores may be advised on greater predilection to WSL development regardless of treatment duration. Those with poor pre-treatment OH may benefit from greater reinforcement and monitoring of OH. Placement of orthodontic sealants on facial tooth surfaces prior to bonding fixed appliances should be considered to increase prevention of WSLs. / Oral Biology

Introduction: When evaluating the etiology of a malocclusion, a multitude of analyses exist for evaluating skeletal, dental, and soft tissue features of the patient. However, there is no current systemized orthodontic protocol for evaluating the tongue position and size. The tongue is the largest organ in the oral cavity and has a significant impact on the positioning of the dentoalveolar structures. The Modified Mallampati Tongue (MMT) score is a reliable method of estimating tongue size and position relative to the oral cavity. While the MMT is commonly used in anesthesiology for pre-anesthetic airway assessment, it is a simple and reproducible test to evaluate the tongue size and position. This study aims to determine if the Modified Mallampati Tongue Score, along with cephalometric evaluation of the tongue height and size, can be used as a diagnostic tool to assist in determining the etiology of certain malocclusions.Materials and Methods: Pre-treatment photographs, lateral cephalograms, and intraoral dental scans of 450 patients treated at Temple University Kornberg School of Dentistry (TUKSoD) Department of Orthodontics were studied. The sample includes patients of any age group, gender, or ethnicity. Cephalometric linear measurements of tongue height and length, as well as molar position, were conducted on Amira Morphometrics software. Angular measurements of upper and lower incisor inclination were computed from lateral cephalograms on Dolphin Imaging software. Three- dimensional digital cast analysis, acquired from intraoral dental scans, were performed on Invisalign ITERO software to measure dentometric dimensions, such as arch perimeter, arch length, and arch width. Quantitative analysis was completed to compare tongue position and size to dentoalveolar arch dimensions, as well as tooth position and angulation. Probability values of <0.05 were accepted as significant. Results: A total of 189 patients (72.5% Female, 27.5% Male, 54% African American), with a mean age of 20 (Range 7-73), were included for the study. Lower incisor angulation was the only dental cephalometric measurement with positive correlation to MMT (p=0.038). Tongue length, however, correlated positively with all but one dental cephalometric measurement (p 0.004 to <0.001). Tongue height had positive correlations with both dental cephalometric and arch dimensional measurements: maxillary and mandibular molar position (p=<0.001), maxillary canine width (p=<0.001) and premolar width (p=0.011), and maxillary arch perimeter (p=0.046). Regression analysis showed that gender and ethnicity have statistically significant effects on multiple variables, where males and African Americans frequently had greater dentoalveolar measurements compared to females or other ethnicities, respectively. Conclusion: MMT scores do not help estimate dental arch size or tooth location. Tongue length and height, however, showed significant relationships to dental arch dimensions and tooth positions. This suggests that cephalometric soft tissue analysis of the tongue position is an effective predictor of dentoalveolar positioning, enhancing diagnosis, prognosis, and retention decisions in orthodontic treatment planning. / Oral Biology

Objectives: The Salzmann Evaluation Index (SEI) is the malocclusion index used by Medicaid insurance administrators in Pennsylvania. An SEI of 25 is regarded as the threshold for approval. The SEI is broken into three subsections: intra-arch deviations (IAD; discrepancies within an arch), anterior Inter-arch deviations (AIAD; incisor antagonist relationships) and posterior inter-arch deviations (PIAD; posterior antagonist). This study identified discrepancies amongst the overall SEI score and subsection scores, in approved or denied cases with a SEI>25. Differences in subsection scores may identify malocclusion characteristics, other than overall scores, which drive insurance approval. Methods: The study sample included 570 subjects (295 approved and 275 denied). All subjects had a SEI>25. These scores along with a cephalogram, panorex, and intra/extra oral photographs, were previously sent to the administrator and a funding decision was rendered. SEI and subsection scores were compared between approved or denied treatment funding by T-Tests. Results: There was a significant difference in the overall SEI score between approved and denied records (p<0.001), with higher scores more likely to obtain approval. No difference was found for the IAD (p=0.195). Significant difference between approved and denied scores were found for both AIAD and PIAD (p<0.001). Effective subsection weight of contribution to the overall SEI was: IAD=55.38%, AIAD=24.86%, and PIAD=19.76%. Conclusions: Only 51.75% of subjects that had an SEI> 25 were awarded treatment funding. Although IAD contributes over half the total SEI, differences in this portion did not effectively influence insurance administrator decisions. There may be an inherent approval bias favoring malocclusions with crossbite, open bite, overbite, overjet, and sagittal tooth positions, rather than tooth-in-arch positions or overall SEI score. / Oral Biology

Objectives: The aim of this systematic review was to collect and review literature that used cone beam computer tomography (CBCT) imaging to study changes in the upper airway of adults who have undergone orthodontic treatment which retracted incisors. Methods: Pubmed, Mbase, Dentistry and Oral Science Source, and Web of Science databases were searched for relevant articles in English which met the inclusion criteria. Included articles had adult subjects orthodontically treated to retract incisors with pre- and post- treatment CBCT images. Excluded studies were case studies, opinion pieces, studies with adolescent subjects under 18 years old, or subjects with medical conditions or respiratory diseases. Studies were appraised using Joanna Briggs Institute appraisal index for cohort studies. Data collected included the sample size, age, treatment type, changes in airway volume, minimum cross-sectional area, and incisor retraction. Outcomes were analyzed using Forest Plots. Results: Of the 1,314 studies found through search, 3 retrospective cohort studies were included. These studies represented 229 total participant, 154 extraction and 75 non-extraction. All studies found no significance between incisor retraction and airway dimensions between extraction and non-extraction groups. However, within the extraction group, one study found an increase in oropharyngeal volume, while another found a significant inverse correlation of maxillary distalization and airway volume. One study found significant posterior position of hyoid in the extraction group. The studies had moderate risk of bias. Conclusion: Included studies have varying results on airway dimensions and volume that are small, and risk of bias cannot be ignored. The latest evidence for changes in arch length and incisor position on the airway with 3D imaging is weak. There is evidence that airway dimensions change in an adaptive manner to compensate for arch length and incisor position changes, which explains lack of significant changes in airway volume. / Oral Biology

Objective: The aim of this study was to investigate the effect of extraction and non-extraction orthodontic treatments on oral commissures.Materials & Methods: Pre- and post-treatment 3dMD images of 47 patients aged 10-19 were studied for changes in inner and outer commissure width, philtrum height and buccal corridor width. The subjects either had extractions of all four first premolars, upper first premolars only, or were treated non-extraction. The superimposed 3dMD images were collected and qualitative and quantitative analyses were completed using 3dMD Vultus software. Interincisal angle and upper incisor to NA changes were also calculated using pre- and post-treatment lateral cephalograms. Regression analyses were applied controlling for age, gender, ethnicity, angle classification, and treatment time. Results: While all groups showed a nominal increase in the inner and outer commissure widths from T0 to T1, only the non-extraction group revealed a statistically significant change (p < .05). Buccal corridor width increased in all three groups but was only statistically significant in the extraction of four first premolar extraction group (p < .02). Treatment type had no statistically significant influence on philtrum height and interincisal angle among the three groups. Qualitatively, the commissures exhibited variable changes regardless of treatment type but trended to exhibit more of a positive change for the extraction of upper/lower first premolar group. Conclusion: Extraction of either all four premolars or upper premolars only does not appear to be associated with a measurable change in the commissure width. An increase in buccal corridor width was highly associated with four first premolar extractions and increased with age. Incisor inclination was strongly correlated with four first premolar extractions and resulted in a greater change in outer commissure width. Philtrum height remained relatively unchanged in all three groups accounting for age, treatment time, and gender indicating that this is a relatively stable structure during growth and shows minimal change with orthodontic treatment. / Oral Biology

Introduction: Localized infection to pulp tissue results in a vascular response. The endothelial cells of the microvasculature contract and become leaky, so that high molecular weight plasma proteins accumulate in the affected site. This inflammation is initiated and controlled by chemical mediators known as the kinins. The kininogens are multifunctional plasma proteins that participate in various phases of the inflammatory process. Both high molecular weight kininogen (HK) and low molecular weight kininogen (LK) contain the vasodilatory nonapeptide bradykinin (Bk). The interaction of kininogen with bacteria frequently found in infections of the pulp has not been investigated. Hence, we propose to study the in vitro effect of three endodontic pathogens on kininogen. A related aim is to characterize the kininogenase activity of Porphyromonas endodontalis.Purpose: This study aims to determine the significant in vitro interaction between P. endodontalis, an endodontic pathogen, and the plasma proteins kininogen, a modulator of the inflammatory response, and fibrinogen, a major protein substrate of the coagulation cascade. Materials and Methods: Whole cells (105 cells/µl) or sonic extracts (1mg/ml) of the endodontic pathogens P. endodontalis, Enterococcus faecalis, and Fusobacterium nucleatum were incubated with low molecular weight kininogen (LMWK) (0.1mg/ml) and fibrinogen (0.1mg/ml) for 1 hour, 4 hours and 24 hours at 37C. Degradation of these proteins was detected by polyacrylamide gel electrophoresis (PAGE). Kininogenase activity was assayed by incubating P. endodontalis sonic extracts (PESE, 30l, 1mg/ml) or purified fractions of PESE with either chromogenic amide substrate N-benzoyl-pro-phe-arg-pNA (70l, 7M) or LMWK (70l, 0.1mg/ml, 10-3M). Release of pNA was determined spectrophotometrically and release of bradykinin from kininogen was measured by a competitive enzyme-linked immunosorbent assay (ELISA). Kinogenase activity was partially purified from PESE by gel chromatography and characterized by assaying in the presence of protease inhibitors. Results: P. endodontalis sonic extract (PESE) degraded both kininogen and fibrinogen as evidenced by PAGE. Sonic extracts of E. faecalis and F. nucleatum did not exhibit this activity. PESE also cleaved the protease substrate at the arginine residue releasing pNA linearly. Bradykinin (100pg/ml) was released from LMWK when incubated with PESE. Kininogenase activity of P. endodontalis was purified 17 fold and characterized as a kallikrein-like serine protease. Conclusion: PGSE degrades both kininogen and fibrinogen in vitro. These data suggest that P. endodontalis may contribute to the pathogenesis of pulpitis and periodontitis by modulating the inflammatory response via its effect on LMWK as well as hemostasis by its ability to degrade fibrinogen. / Oral Biology